JPH07226864A - Device for emphasizing contour of video signal - Google Patents

Abstract

PURPOSE:To obtain an inexpensive device with high stability by changing-over the plural longitudinal contour emphasizing means of a video signal so as to permit the corresponding one to be cooperatively used with the changeover operation of the horizontal contour emphasizing means of the video signal. CONSTITUTION:A coefficient equipment 5 inverts the polarity of a signal supplied to it and also outputs the signal Sa whose amplitude is made to be a half. The coefficient equipment 6 outputs the signal Sb whose amplitude is made to be twice as big as the supplied signal. The coefficient equipment 7 inverts the polarity of the signal supplied to it and also outputs the signal Sc whose amplitude is made to be a half. When the respective signals Sa-Sc outputted from the respective coefficient equipments 5-T are added in an adder 8, the video signal Sd where contour emphasis is conducted in both edges is transmitted to an output terminal 2. Then, in accordance with the detection result of a horizontal scanning cycle in a change-over signal generating part 27, change-over is automatically conducted by change-over switches SW1 and SW2 so as to permit a prescribed delay element to be selected within the respective delay elements 3a-3d and 4a-4d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal contour enhancement apparatus.

[0002]

2. Description of the Related Art Transmission and recording of an image as a video signal (image signal) corresponding to a specific pixel array on the time axis according to a predetermined scanning standard has been conventionally performed in the technical field of television, recording. It is well known that it is widely used in the technical field of reproduction, the technical field of image processing and the like, and that the above-mentioned scanning standard is appropriately selected from many types and adopted. By the way, when a video signal is supplied to a display and an image is displayed on the display surface of the display, as one means for meeting the demand for high quality of the display image, the sharpness of the display image is improved. Therefore, horizontal contour enhancement and vertical contour enhancement may be performed on the video signal.

FIGS. 5 to 7 are views for explaining a conventional example of a contour enhancement apparatus for a video signal. In each drawing, 1 is an input terminal of a contoured video signal and 2 is a contour. This is an output terminal for the emphasized video signal. First,
In the video signal contour enhancement apparatus illustrated in FIG. 5,
Reference numerals 3 and 4 are delay elements capable of delaying the video signal targeted for contour enhancement by a predetermined time length (1S), and 5 to 7 are coefficient multipliers, respectively. 8 is an adder. The coefficient unit 5 is
A signal Sa whose polarity is inverted and the amplitude of which is halved is supplied to the signal Sa (Sa shown in (a) of FIG. 5).
Is output, and the coefficient unit 6 can output a signal Sb obtained by doubling the amplitude of the signal supplied thereto (see Sb shown in (b) of FIG. 5). Further, the coefficient unit 7 inverts the polarity of the signal supplied thereto and also halves the amplitude of the signal Sc {see Sc shown in (c) of FIG. 5}. It is configured to output.

When the signals Sa to Sc output from the coefficient units 5 to 7 are added by the adder 8, the adder 8 outputs the signals Sa to Sc as shown in (d) of FIG. The video signal Sd in which both edges (both edges) are edge-enhanced is sent to the output terminal 2. In the contour emphasizing device shown in FIG. 5, if the delay amount (1S) of the delay elements 6 and 4 corresponds to one horizontal pixel, the contour emphasizing device shown in FIG. , And again,
If the delay amount (1S) of the delay elements 3 and 4 corresponds to one horizontal scanning period, the contour emphasizing device shown in FIG. 5 operates as a vertical contour emphasizing device.

Next, in the contour enhancement apparatus for the video signal illustrated in FIG. 6, 9 is capable of delaying the contour of the video signal targeted for contour enhancement by a predetermined time length (1S). Delay elements, such as 10, 11,
Is a coefficient unit, and 12 is an adder. The coefficient unit 10 has a signal Sa having the same amplitude as that of the input only by inverting the polarity of the signal supplied thereto (Sa shown in (a) of FIG. 6).
Is output, and the coefficient unit 11 can output a signal Sb obtained by doubling the amplitude of the signal supplied thereto (see Sb shown in (b) of FIG. 6). Is configured.

When the signals Sa and Sb output from the coefficient units 10 and 11 are added by the adder 12, the adder 12 outputs the signals Sa and Sb as shown in (c) of FIG. Video signal Sc in a state where contour enhancement is applied to one edge (one edge)
Is sent to the output terminal 2. Also in the contour emphasizing device shown in FIG. 6, if the delay amount (1S) of the delay element 9 corresponds to one horizontal pixel, the contour emphasizing device shown in FIG. Of the
If the delay amount (1S) of the delay element 9 corresponds to one horizontal scanning period, the contour emphasizing device shown in FIG. 6 operates as a vertical contour emphasizing device. In the contour emphasizing apparatus having the configuration shown in FIG. 6, the main line signal is prevented from passing through the delay element so that the amplitude characteristic and the phase characteristic of the delay element do not adversely affect the main line signal. However, the contour enhancement is applied only to one edge (trailing edge).

Next, the contour enhancement apparatus for a video signal illustrated in FIG. 7 performs contour enhancement operation by digital signal processing, and is generally called a Laplacian filter. In FIG. 7, reference numeral 13 is an analog-digital converter for converting an analog video signal, which is supplied from the input terminal 1 and is subjected to contour enhancement, into a digital video signal, and 14, 15 are for one horizontal scanning period. A delay element that gives a time delay to a digital video signal,
Reference numerals 16 to 19 denote delay elements that give a time delay of one pixel period to the digital video signal, 20 to 24 are coefficient units, 25 is an adder, and 26 is a digital-analog converter.

In the coefficient units 20 to 24, the coefficient values Ko, K1 and K2 shown in the figure are calculated as Ko + 2K1 + 2K2.
The coefficient multiplier 22 configured to have a coefficient value defined to satisfy the relation = 1 holds the center signal Ko times the center signal, and The vertical (vertical) direction is multiplied by K1 by the coefficient units 20 and 24 having the coefficient value K1, and further, K2 is multiplied by the coefficient units 21 and 23 having the coefficient value K2 in the horizontal (horizontal) direction with respect to the center signal. By multiplying, the digital video signal, which functions as a Laplacian filter and is subjected to horizontal contour enhancement and vertical contour enhancement, is supplied from the adder 25 to the digital-analog converter 26, and from the digital-analog converter 26. An analog video signal subjected to horizontal contour enhancement and vertical contour enhancement is output via the output terminal 2.

[0009]

5 to 7 described above.
In the conventional video signal contour enhancement apparatus described with reference to FIG. 5, the conventional video signal contour enhancement apparatus described with reference to FIGS. 5 and 6 applies contour enhancement to an analog video signal. In addition, the delay element configured as having a predetermined fixed time delay amount is used as a part of the constituent members. By the way, the above delay element becomes expensive when the delay time is long, and becomes extremely expensive when the delay element has a wide band. The delay time of the delay element is determined according to the horizontal scanning frequency (horizontal synchronization frequency) in the video signal targeted for contour enhancement. If it is not limited to the above, it is necessary that the contour enhancement device for the video signal is configured by using the delay element having the specific delay time for each video signal complying with the different scanning standard. It is said that

Therefore, for example, when a video signal conforming to a specific scanning standard is supplied from among many video signals conforming to different scanning standards as a video signal to be selectively subjected to contour enhancement, In order to be able to perform a predetermined contour enhancement operation regardless of which video signal among the many video signals according to each of the different scanning standards of FIG.
When data is included, it is necessary to prepare a delay element of a delay time type corresponding to a number close to infinity), but such a thing is not feasible. Further, in the case where the video signals to be subject to edge enhancement are many video signals that respectively comply with different scanning standards, the video signal with the maximum horizontal scanning frequency among the many video signals described above is
Assuming that the horizontal scanning frequency is 90 KHz and the horizontal resolution is equivalent to 1500 pixels, the delay element used in the contour emphasizing device to perform contour emphasizing on such a video signal is a blanking period. Also considering about 15
A wide band such as 0 MHz is required, but it is extremely difficult to realize the wide band delay element as described above by a current delay element for analog signals such as a glass delay line. is there. Since the delay element for the analog signal has poor amplitude characteristics and phase characteristics, a contour enhancement apparatus for a video signal that contour enhances an analog video signal cannot have good overall characteristics.

Next, the contour enhancement device for a video signal described above with reference to FIG. 7, that is, the Laplacian filter in which the contour enhancement operation is performed by digital signal processing, performs calculation on adjacent pixels between horizontal and vertical directions. So, the clock signal (pulse) for digital signal processing,
Follows changes in the horizontal scanning frequency (horizontal synchronization frequency) in the video signal targeted for contour enhancement, with its repetition frequency being an integral multiple of the horizontal scanning frequency (horizontal synchronization frequency) in the video signal targeted for contour enhancement In this way, even if a video signal complying with a specific scanning standard is supplied as a video signal to be subjected to edge enhancement selectively from among many video signals complying with different scanning standards. It is considered that a predetermined contour enhancement operation can be performed.

However, in the case where a large number of video signals complying with different scanning standards are the video signals to be subjected to contour enhancement, the video signal having the maximum horizontal scanning frequency among the above-mentioned many video signals. But, for example, 90KH
Assuming that the number of pixels is 1500 at the horizontal scanning frequency of z, the clock signal for digital signal processing used in the edge enhancing device to apply edge enhancement to such a video signal is the blanking period. Considering also about 150MHz
The analog-to-digital converter, which has such a high frequency and satisfies the depth of 8 bits required when digitizing a video signal, is expensive, and therefore the outline of the above-described configuration is required. The highlighting device is not realistic.

When the clock signal for signal processing of the digital signal has a high repetition frequency of 150 MHz as described above, it is used as delay means for the digital video signal. Considering the stability of the memory operation, the signal processing of digital signals is performed in parallel, which makes the device configuration complicated and expensive, as well as the horizontal scanning of the video signal that is the object of contour enhancement. In the case where the ratio of the maximum value and the minimum value of the horizontal scanning frequency of the video signal targeted for contour enhancement is 6 times such that the frequency changes in the range of 15 KHz to 90 KHz, for example, the above digital Also as an oscillator used for generating a clock signal for signal processing of a signal, its oscillation frequency value is 6 with respect to the change of the horizontal synchronizing frequency of the input video signal. Although it is necessary to stably synchronize the change range and change a wide range of frequencies as described above, it is difficult to stably synchronize the horizontal synchronizing frequency of the input video signal.

As described above with reference to FIGS. 5 to 7, in the conventional contour emphasizing apparatus which performs the contour emphasizing operation with the analog signal, the video signal to be the object of the contour emphasizing is performed. As a result, it is technically difficult to have a structure that can cope with a case where a plurality of video signals with different horizontal scanning standards are selectively supplied. Even if a plurality of different horizontal scanning standards are selected and a contour emphasizing device is configured so that the contour emphasizing operation can be performed only for a video signal complying with the selected horizontal scanning standard, it is extremely expensive. That is a problem. Further, in the conventional contour emphasizing apparatus which performs the contour emphasizing operation by a digital signal, even if a plurality of video signals having different horizontal scanning standards are selectively supplied, it has a structure capable of coping with that. However, in addition to the fact that a very expensive component is required as a component for configuring the device, there is a problem in that synchronization stability is also difficult and jitter easily occurs. Therefore, a contour enhancement device that does not have the above-mentioned problems has been sought.

[0015]

According to the present invention, the frequency range of the horizontal synchronizing frequency in a video signal to be subjected to contour enhancement is divided into a plurality of predetermined frequency regions, and each of the regions obtained by the division is obtained. Each of the above-mentioned individual horizontal contour enhancement means is configured to perform horizontal contour enhancement on a video signal targeted for contour enhancement by the horizontal contour enhancement frequency set individually for each frequency region. Corresponding to the horizontal scanning standard of the video signal that is provided for each frequency region and is targeted for contour enhancement, a predetermined one of the horizontal contour enhancement means provided for each frequency region is switched. And a delay means having a specific delay time for each of the above-mentioned frequency regions, and a video signal between adjacent horizontal scanning lines is used. A vertical contour enhancement means of a plurality of video signal for vertical contour enhancement operation of the video signal by edge enhancement,
A means for switching and using a predetermined one of the vertical contour enhancing means for the video signal provided for each frequency region in conjunction with the switching operation of the horizontal contour enhancing means for the video signal. And a horizontal synchronizing frequency in a video signal targeted for contour enhancement so that a contour enhancement operation for a plurality of video signals having different horizontal scanning standards can be performed. The frequency range of is divided into a plurality of predetermined frequency regions, and the horizontal contour enhancement frequency is set individually for each frequency region obtained by the above-mentioned division, and horizontal contour enhancement is performed on the video signal in the analog signal form. An individual horizontal contour emphasizing circuit configured so that it can be performed is provided for each of the above frequency regions, and is supplied as a target of contour emphasizing. Corresponding to the horizontal scanning standard of the video signal, a means for switching and using a predetermined one of the horizontal contour emphasizing circuits of the analog video signal provided for each frequency region, and the adjacent horizontal scanning The vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal between lines divides the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions, and obtains each frequency region described above. A digital signal for performing vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines, as is performed for a video signal in a digital signal form in a predetermined state set for each As a processing circuit, an analog-digital converter, a delay unit for one horizontal scanning period by a digital memory, and an adder are used to form a vertical edge of a video signal by trailing edge enhancement. And a digital-analog converter for converting the vertical contour signal of the video signal outputted from the vertical contour signal generation means of the video signal by the above-mentioned trailing edge enhancement into a digital-analog signal and outputting it. Of the video signal, which is configured as described above and includes means for switching the repetition frequency of the pulse to a predetermined frequency value in conjunction with the switching operation of the horizontal contour emphasis circuit for the video signal. An edge-to-edge converter or a digital signal processing circuit for performing a vertical edge-enhancing operation of a video signal by trailing edge enhancement using an image signal between adjacent horizontal scanning lines as an analog-digital converter and one horizontal scanning period by a digital memory. A plurality of sets of vertical contour signal generating means for the video signal by the trailing edge enhancement configured using the delay means and the adding means of Means for operating each of the means for generating the vertical contour signal of the video signal by the trailing edge enhancement with a pulse having the same frequency and different phases from each other; It is configured to include means for converting vertical contour signals of video signals simultaneously output from the means for generating vertical contour signals into serial signals, and a digital-analog converter for performing digital-analog conversion of the serial signals and outputting the serial signals. And a means for switching the repetition frequency of the pulse to a predetermined frequency value in conjunction with the switching operation of the horizontal contour emphasizing circuit for the video signal described above. A vertical contour of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines An analog-to-digital converter as a digital signal processing circuit for performing the adjusting operation, a means for delaying one horizontal scanning period by a digital memory, and an adding means for generating a vertical contour signal of a video signal by trailing edge enhancement. A plurality of sets, each of the means for generating the vertical contour signal of the video signal by the trailing edge enhancement,
A serial signal is a vertical contour signal of a video signal that is simultaneously output from the means for generating a vertical contour signal of a video signal by a plurality of trailing edge enhancements, which are operated by pulses having the same frequency but different phases. With the configuration to output after digital-analog conversion after conversion to, set the repetition frequency value of the pulse to the frequency value of a specific magnification of the horizontal synchronizing frequency in the video signal that is the object of contour enhancement, The pulse is generated by a phase-locked loop including a programmable counter, and the frequency division ratio of the programmable counter corresponds to the horizontal synchronizing frequency in the video signal targeted for contour enhancement. A video signal contour enhancement device configured to be set to a predetermined value,
And in the above-described contour enhancement device for a video signal, the horizontal scanning cycle of the video signal supplied to be targeted for contour enhancement is detected, and the video signal is detected in correspondence with the horizontal scanning cycle of the detected video signal. The horizontal contour emphasis frequency set in each frequency region obtained by dividing the frequency range of the horizontal synchronization frequency is automatically switched, and the image supplied to be the target of contour emphasis is supplied. A digital signal that detects a horizontal scanning period of a signal and performs vertical edge enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines in correspondence with the detected horizontal scanning period of the video signal. The repetition frequency value of the pulse that operates the signal processing circuit is a frequency value that is a predetermined integer multiple of the horizontal synchronization frequency value in the video signal that is the target of edge enhancement. Providing a contour emphasizing device image signal ratio has to be automatically switched to setting.

[0016]

When a plurality of video signals having different horizontal scanning standards are targeted for contour enhancement, the frequency range of the horizontal synchronizing frequency in the video signal is divided into a plurality of predetermined frequency regions, and the above-mentioned division is performed. The horizontal contour emphasis frequency is set individually for each frequency region obtained by. The horizontal contour emphasizing means including delay means having a specific delay time for each of the frequency regions is associated with the horizontal scanning standard of the video signal to be subjected to contour emphasizing. Switching is performed so that a corresponding predetermined one of the horizontal contour enhancing means provided for each frequency domain is used.
A plurality of delay units each having a specific delay time for each frequency region are included, and a plurality of vertical contour enhancement operations for a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines are performed. The vertical contour emphasizing means of the video signal is interlocked with the switching operation of the horizontal contour emphasizing means of the video signal described above, and a corresponding predetermined one of the vertical contour emphasizing means of the video signal provided for each of the frequency regions described above. Switch to one used.

In order to be able to perform the edge enhancement operation for a plurality of video signals having different horizontal scanning standards,
The frequency range of the horizontal synchronizing frequency in the video signal targeted for contour enhancement is divided into a plurality of predetermined frequency regions, and the horizontal contour enhancement is set individually for each of the divided frequency regions. In order to perform horizontal contour enhancement on a video signal in the form of an analog signal at a frequency, a horizontal contour enhancement circuit for an analog video signal configured by including delay elements having specific delay times for each frequency region is Provided in accordance with the horizontal scanning standard of the video signal targeted for contour enhancement based on the detection result of the horizontal scanning period performed on the video signal targeted for contour enhancement. The corresponding one in the horizontal contour enhancement circuit of the acquired analog video signal is automatically switched to be used.

In addition, the frequency range of the horizontal synchronizing frequency of the video signal is divided into a plurality of predetermined frequency regions, and each of the above-mentioned frequency regions is obtained as a digital signal in a predetermined state set individually. As a digital signal processing circuit for performing a vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines performed for the video signal of In the case where a digital signal processing circuit having a configuration using only one set of vertical contour signal generation means for a video signal by trailing edge enhancement constituted by delay means and addition means is used, the vertical contour is used. The vertical contour signal of the video signal output from the signal generating means is converted into an analog signal by the digital-analog converter and output.

The pulse for operating the digital signal processing circuit having the above-described structure for performing the vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal between the adjacent horizontal scanning lines is targeted for contour enhancement. Based on the detection result of the horizontal scanning cycle of the video signal that is present, the magnification for setting a frequency value that is a predetermined integral multiple with respect to the horizontal synchronization frequency value in the video signal that is the target of edge enhancement is The repetition frequency value of the video signal is automatically switched in conjunction with the switching operation of the horizontal contour emphasizing circuit of the video signal, the analog-digital converter and the delay means for one horizontal scanning period by the digital memory, A digital signal processing circuit having a configuration mode using only one set of a vertical edge signal generating means for a video signal by trailing edge emphasis configured by using an adding means. Thus, the video signal in the form of a digital signal in a predetermined state is set individually for each of the above-mentioned frequency regions obtained by dividing the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions. The vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal between adjacent horizontal scanning lines, which is performed on the signal, is favorably performed.

A digital signal form is set in a predetermined state individually set for each of the above-mentioned frequency regions obtained by dividing the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions. As a digital signal processing circuit for performing a vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines performed for the video signal, a plurality of frequency ranges of horizontal synchronizing frequencies of the video signal are predetermined. A trailing edge using a video signal between adjacent horizontal scanning lines, which is performed on a video signal in the form of a digital signal in a predetermined state set individually for each of the above-mentioned frequency regions obtained by dividing the frequency region. 1 horizontal scan by an analog-to-digital converter in a digital signal processing circuit that performs vertical contour enhancement operation of a video signal by enhancement and a digital memory In the case of a digital signal processing circuit having a plurality of sets of means for generating a vertical contour signal of a video signal by trailing edge emphasizing which is configured by using a delay means between Each of the means for generating the vertical contour signal of the video signal is operated by a pulse (clock signal) having the same frequency but different phases. Then, the vertical contour signals of the video signals simultaneously output from the plurality of means for generating the vertical contour signals of the video signal by the trailing edge enhancement described above are converted into serial signals by, for example, a latch circuit, and then converted into digital-analog signals. Is converted into an analog signal by the instrument and output.

Based on the detection result of the horizontal scanning cycle of the video signal which is the object of contour enhancement, the vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal between adjacent horizontal scanning lines is performed. The multiplication factor for setting the repetition frequency value of the pulse for operating the digital signal processing circuit to a frequency value that is a predetermined integer multiple of the horizontal synchronization frequency value in the video signal that is the object of contour enhancement is described above. The automatic switching is performed in conjunction with the switching operation of the horizontal contour enhancement circuit for the video signal. The repetition frequency value of the pulse is set to a frequency value of a specific scaling factor of the horizontal synchronizing frequency in the video signal targeted for contour enhancement, and the division ratio is targeted for contour enhancement. Is generated by a phase locked loop including a programmable counter set to a predetermined value corresponding to the horizontal synchronizing frequency in the video signal.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The concrete contents of the video signal contour emphasizing apparatus of the present invention will be described in detail below with reference to the accompanying drawings. Figure 1
3 and 4 are block diagrams of a contour enhancement apparatus for video signals according to the present invention, FIGS. 2 and 4 are partial block diagrams of the configuration of the contour enhancement apparatus for video signals according to the present invention, and FIGS. FIG. 8 is a block diagram of the contour enhancing apparatus of FIG. 8, and FIG. 8 is a block diagram of an example configuration of the vertical contour enhancing apparatus. First, FIG. 1 is a block diagram when the contour enhancement apparatus for a video signal of the present invention is implemented as a horizontal contour enhancement apparatus. In the figure, 1 is an input terminal of a video signal which is a target of contour enhancement, and 2 is a contour. This is an output terminal for the emphasized video signal. 3G in the figure, when performing horizontal contour enhancement on video signals having different horizontal scanning standards which are targets of contour enhancement,
A delay element group provided with delay elements 3a, 3b ... Which can be delayed by required predetermined different time lengths (1.tau .... 1 pixel period), respectively. 4G is a predetermined different time length (1τ ... 1 pixel period) required when performing horizontal contour enhancement on video signals having different horizontal scanning standards which are targets of contour enhancement. Is a delay element group including delay elements 4a, 4b ...

Each of the delay elements 3a, 3b, 3c ... Forming the delay element group 3G and each of the delay elements 4a, 4b, 4c ... Forming the delay element group 4G are targeted for contour enhancement. The frequency range of the horizontal scanning frequency (horizontal synchronization frequency) of the video signal being generated is divided into a plurality of predetermined frequency regions, and the horizontal contour emphasis frequency is set individually for each frequency region. When the horizontal contour emphasizing operation is performed, the delay time value can be selectively used. The numerical values shown in the column of the delay time value in "Table 1" below indicate that the horizontal scanning frequency (horizontal synchronizing frequency) of the video signal to be subjected to contour enhancement is within the frequency range of 15 KHz to 90 KHz, for example. In the case of a plurality of video signals as described above, the frequency range of the horizontal synchronizing frequency is divided into seven frequency regions as described in the column of the horizontal synchronizing frequency in "Table 1", and "Table 1" for each of the 7 frequency regions
When the emphasis frequency as described in the emphasis frequency column is set, the delay elements 3a, 3b, 3c ..., 4a, 4 forming the delay element groups 3G, 4G described above are set.
The delay time values required for b, 4c ...

[0024]

[Table 1]

.. constituting the delay element group 3G shown in FIG. 1 and delay elements 4a, 4b, 4c .. constituting the delay element group 4G. Is a changeover switch SW to which the changeover control signal generated by the changeover signal generator 27 is supplied via the transmission line 29.
With 1 and SW2, the corresponding delay elements (for example, delay elements 3a and delay elements 4a, delay elements 3b and delay elements 4b, which have the same subscript) are synchronized. Can be switched. Delay element group 3G described above
Of the delay elements 3a, 3b, 3c ... and the delay elements 4a, 4b, 4c of the delay element group 4G.
.., the delay element 3a and the delay element 4a are each configured to have a delay time of 71 nanoseconds, and the video signal subjected to the edge enhancement has a frequency of 15 kHz to 15 kHz.
When the horizontal scanning frequency (horizontal synchronizing frequency) is present within the frequency range of 16 KHz, it is selected by the switching operation of the changeover switches SW1 and SW2, and within the above-mentioned frequency range of 15 KHz to 16 KHz. The video signal having the horizontal scanning frequency (horizontal synchronizing frequency) as present in the above is subjected to the horizontal contour enhancement operation at the enhancement frequency of 3.5 MHz (see also Table 1). ).

Further, each of the delay elements 3a, 3b, 3c, ... And the delay element group 4G constituting the delay element group 3G described above.
In each of the delay elements 4a, 4b, 4c, ..., The delay element 3b and the delay element 4b are configured to have a delay time of 41 nanoseconds, respectively, and the video signal subjected to the edge enhancement. But 16 KHz to 20 KH
In the frequency region of 16 KHz to 20 KHz, which is selected by the switching operation of the changeover switches SW1 and SW2 when it has a horizontal scanning frequency (horizontal synchronizing frequency) that exists in the frequency region of z. The video signal having the horizontal scanning frequency (horizontal synchronizing frequency) as present in the above is subjected to the horizontal contour enhancement operation at the enhancement frequency of 6.0 MHz (see also "Table 1"). ).

Thereafter, in the same manner, the delay element group 3 described above is used.
The delay elements 3c, 3d, ..., Which constitute G, the delay elements 4c, 4d, etc., Which constitute the delay element group 4G, and the like, the video signals subjected to the edge enhancement are shown in “Table 1”. In the case where the horizontal scanning frequency (horizontal synchronizing frequency) exists in the sequential frequency region shown, the sequential selection is made by the switching operation of the changeover switches SW1 and SW2. Corresponding to the video signal having the horizontal scanning frequency (horizontal synchronizing frequency) existing in the frequency region of the horizontal contour enhancement operation with the enhancement frequency of the frequency value as shown in "Table 1". To do so. In FIG. 2, which shows a specific configuration example of the switching signal generating unit 27 that supplies the switching control signal to the above-mentioned changeover switches SW1 and SW2 via the transmission path 29, 28 is a composite of video signals to be subjected to contour enhancement. It is an input terminal to which a synchronization signal is supplied. Depending on the configuration of the sync separation circuit provided in the switching signal generator 27, the input terminal 28 of the switching signal generator 27 may be supplied with the video signal targeted for contour enhancement. .

Reference numeral 30 is a horizontal sync separation circuit, 31 is a frequency-voltage converter, 32 is an analog-digital converter, 33 is a switching signal generator constituted by using, for example, a microcomputer, and an input terminal of the switching signal generating section 27. The horizontal sync separation circuit 30, to which the composite sync signal in the video signal targeted for contour enhancement is supplied via 28, separates the horizontal sync signal accompanying the video signal targeted for contour enhancement, It is given to the frequency-voltage converter 31. The frequency-voltage converter 31 supplies the analog-digital converter 32 with an output signal having a voltage value corresponding to the frequency of the horizontal synchronizing signal input thereto. The analog-to-digital converter 32 outputs digital data indicating the frequency of the horizontal synchronizing signal in the video signal targeted for contour enhancement, and the switching signal generator 33 is constructed by using a microcomputer. Given to.

In the switching signal generator 33, "Table 1" is used.
A changeover control signal for selecting a delay element capable of performing a horizontal contour emphasis operation by the changeover switches SW1 and SW2 at a predetermined emphasis frequency indicated by the correspondence relation of each column therein via the transmission line 29. SW1,
Give to SW2. The above-described switching operation by the changeover switches SW1 and SW2 is performed when the video signal targeted for edge enhancement is changed to one having a scanning standard different from the conventional scanning standard. Even if the response time of the switching operation is long, no trouble occurs. As has been clarified in the above description, in the horizontal outline emphasizing device for a video signal shown in FIG. 1, a delay element group including a plurality of delay elements each having a specific delay time for each frequency region is provided. In 3G and 4G, the horizontal synchronization frequency value in the video signal targeted for edge enhancement is
For example, delay elements each having a predetermined delay time value are selected and used according to which of the seven frequency regions listed in the horizontal synchronization frequency column in "Table 1" belongs.

In FIG. 1, 5 to 7 are coefficient units,
Reference numeral 8 denotes an adder, and the coefficient unit 5 inverts the polarity of the signal supplied thereto and halves the amplitude Sa (see, for example, Sa shown in (a) of FIG. 5). }
Is configured to output. Further, the coefficient unit 6 is configured to be able to output a signal Sb obtained by doubling the amplitude of the signal supplied thereto (for example, refer to Sb shown in (b) of FIG. 5). Further, the coefficient unit 7 is configured so as to output a signal Sc (for example, refer to Sc shown in (c) of FIG. 5) whose polarity is inverted and the amplitude thereof is halved. Therefore, the signals Sa to Sc output from the coefficient units 5 to 7 are
When added by the adder 8, the adder 8 sends to the output terminal 2 a video signal Sd in which both edges (both edges) are contour-emphasized as shown in (d) of FIG. To be done.

In the embodiment of the video signal contour enhancing apparatus of the present invention shown in FIG. 1, the frequency range of the horizontal scanning frequency (horizontal synchronizing frequency) of the video signal targeted for contour enhancement is predetermined. An image targeted for contour enhancement so that the horizontal contour enhancement operation can be performed at the individually set horizontal contour enhancement frequency for each frequency domain obtained by dividing the frequency domain. Regarding the signal, each of the delay elements 3a, 3b, 3c ... And the delay element group 4G, which constitute the delay element group 3G as described above, according to the detection result of the horizontal scanning period performed in the switching signal generating unit 27.
Of the delay elements 4a, 4b, 4c ...
By automatically switching by the change-over switches SW1 and SW2 so that a predetermined delay element provided corresponding to the horizontal scanning standard of the video signal targeted for contour enhancement is selected and used, Horizontal scanning frequency (horizontal synchronization frequency) in the video signal that is the target of edge enhancement
Can be set to a good horizontal contour enhancement operation regardless of any frequency value within the frequency range of, for example, 15 KHz to 90 KHz.

According to the present invention, as described above, even if the range of the horizontal scanning frequency (horizontal synchronizing frequency) in the video signal to be subjected to the edge enhancement is wide, for example, 15 KHz to 90 KHz, the above wide frequency range is set. The frequency is divided into any desired number (in the example of Table 1, it is divided into seven frequency regions, but the number of divisions is arbitrary when the present invention is carried out), and each frequency is divided as described above. Each delay element group 3G, 4G should be provided so that the emphasis frequency value can be arbitrarily set for each area and a good horizontal contour emphasis operation can be performed at the emphasis frequency set for each frequency area. Each delay element 3a, 3b, 3c ... 4a,
The delay time values of 4b, 4c ... Are determined, and the delay time values of the delay elements 3a, 3b, 3c ... 4a, 4b, 4c. For example, as in the example shown in "Table 1," the delay element groups 3G and 4 are of the order of nanoseconds.
Since each delay element to be provided in G can be easily configured to have a predetermined performance at a low cost even with a general lumped constant circuit, a plurality of types of delay elements are required to perform signal processing in an analog signal state. Even if the horizontal contour enhancement device is configured as a configuration mode in which
The above-mentioned problems with the conventional device do not occur.

Before going into the description of the vertical contour emphasizing apparatus illustrated in FIG. 3 as an embodiment of the vertical contour emphasizing apparatus of the present invention, first, the description will be made so far with reference to FIG. As in the case of the horizontal contour emphasizing device, the vertical contour emphasizing device also sets the frequency range of the horizontal scanning frequency (horizontal synchronizing frequency) of the video signal targeted for contour emphasizing to a plurality of predetermined frequency regions. A vertical contour emphasizing device as illustrated in FIG. 8 in which the vertical contour emphasizing operation at the vertical contour emphasizing frequency set individually for each frequency region obtained by dividing into think about.

In FIG. 8, reference numeral 1 is an input terminal for a video signal to be subjected to contour enhancement, 2 is an output terminal for a video signal subjected to vertical contour enhancement, and 34 is a low-pass filter. The low pass filter 34 is provided to limit the band of the vertical contour enhancement signal generated by the vertical contour enhancement device. That is, in the vertical contour emphasis device, the delay elements 36 to 39 used in the construction thereof have a delay time corresponding to one horizontal scanning period (1H) in the video signal targeted for contour emphasis. The frequency band of the vertical edge enhancement signal is 1 of the frequency band of the video signal (main line signal) targeted for edge enhancement.
This is because a satisfactory vertical contour enhancement effect can be obtained even when it is about / 4.

The delay elements 36 to 39 have a range of horizontal scanning frequency (horizontal synchronizing frequency) in a video signal which is subject to a plurality of contour enhancements having different scanning standards, for example, a frequency range such as 15 KHz to 90 KHz. Is a delay element having a delay time of 1 horizontal scanning period (1H) set for each frequency region obtained by dividing it into any desired number, 40 and 41 are coefficient units, and 43 is a switching unit. A switch, 42 is an adder, and 35 is a delay element for delay matching. The delay element for delay adjustment 35 is provided with a main line signal so that the video signal (main line signal) to be subjected to contour emphasis and the vertical contour signal can be added in an appropriate state on the time axis in the adder 42. It is to give a time delay to.

The vertical contour emphasizing device shown in FIG. 8 adds the contour emphasizing signal formed by using the narrow band signal obtained by band-limiting the main line signal by the low-pass filter 34 and the main line signal. By doing so, the 1H delay element in the vertical contour enhancing device configured so that the vertical contour enhancing operation by the trailing edge enhancement is performed by the analog video signal,
The frequency range of the horizontal scanning frequency (horizontal synchronizing frequency) of the target video signal is divided into a plurality of predetermined frequency regions, and each frequency region obtained by dividing the frequency range into 1H .. are provided as the delay elements 36 to 39, and each of the 1H delay elements 36 to 39 for analog video signals described above is a predetermined delay element corresponding to the horizontal scanning standard of the video signal subjected to the edge enhancement. Is selectively used by the change-over switch 43 so that a predetermined vertical contour emphasizing operation is performed {see (a) to (d) of FIG. 8}.

When the vertical contour emphasizing device is configured as shown in FIG. 8, the narrow band narrow band obtained by band limiting the main line signal by the low pass filter 34 is used. Since the vertical contour enhancement signal is generated by using the signal, a narrow band element can be adopted as the 1H delay element for the analog video signal used in the configuration of the apparatus, so that the apparatus can be easily realized. But,
(1) The video signal to which the vertical contour enhancement should be applied is limited depending on how the delay time of the 1H delay element for the analog video signal used is set. (2)
Even a narrow band 1H delay element for analog video signals is expensive. Due to such problems as described above, it is not possible to employ the vertical contour enhancement device having the configuration as illustrated in FIG.

FIG. 3 is a block diagram of an example configuration in which the contour enhancement apparatus for a video signal according to the present invention is implemented as a vertical contour enhancement apparatus. In FIG. 3, reference numeral 1 denotes an input of a video signal to be contour enhanced. Terminals 2 are output terminals for the video signal with contour enhancement. The video signal, which is supplied to the video signal input terminal 1 and is targeted for contour enhancement, is supplied to the low-pass filter 34 and the delay element 35 for delay adjustment. The delay element 35 for delay adjustment described above, like the delay element 35 for delay adjustment in FIG. 8, adds the video signal (main line signal) to be subjected to vertical contour emphasis and the vertical contour signal. Is to give a time delay to the main line signal so that the signals can be added in an appropriate state on the time axis. The low-pass filter 34 described above is provided for the same reason as the reason for the low-pass filter 34 shown in FIG.
In 4, the band limitation of the vertical contour enhancement signal generated by the vertical contour enhancement device is performed. For example, the aforementioned low pass filter 34
Thus, the frequency band of the vertical contour emphasis signal is limited to a narrow band of about 1/4 of the frequency band of the video signal (main line signal) targeted for contour emphasis.

The video signal band-limited by the above-mentioned low-pass filter 34 is supplied to a vertical contour signal generator 44 which is configured to perform signal processing by a digital signal. The vertical contour signal generator 44 is
Analog-to-digital converter ADC and delay means (1H delay element) 1HDL for one horizontal scanning period by digital memory
, An inverter INV, an adder ADD, and a digital-analog converter DAC. For example, the vertical contour signal generation unit 44 includes one analog-digital converter ADC, one horizontal scanning period delay means (1H delay element) 1HDL by one digital memory, and one inverter INV. Also, in the case of being configured by one adder ADD and one digital-analog converter DAC, the adder 42 outputs the vertical contour emphasis signal (vertical contour emphasis signal of analog signal) by the trailing edge emphasis. Can be supplied to.

However, the vertical contour signal generator 44 described above is used.
As a configuration mode of the one analog-to-digital converter AD
C, delay means (1H delay element) 1HDL for one horizontal scanning period by one digital memory, and one inverter I
A plurality of sets (arbitrary number of two or more sets) of component parts, each of which has an NV and one adder ADD and is configured to generate a vertical contour enhancement signal in a digital signal form, are provided. Each of the constituent parts of the set is operated by clock signals (pulses) having the same frequency but different phases from each other, and digital signals respectively output from the plurality of constituent parts at the same time. The vertical contour signal of the signal,
A configuration mode in which the latch circuit LAT converts the serial signal into a serial signal, and the digital-analog converter DAC converts the serial signal into an analog signal so that the vertical contour emphasis signal of the analog signal can be supplied to the adder 42. However, a clock signal having a low repetition frequency can be used as a clock signal used for digital signal processing, an inexpensive analog-to-digital converter ADC, a memory, and the like can be used, and stable digital signal processing can be performed. It is advantageous because various advantages such as being possible can be obtained.

In the vertical contour emphasizing apparatus illustrated in FIG. 3, the two component parts 44a and 44b in the vertical contour signal generating section 44 of the vertical contour emphasizing device are one analog digital converter ADC and one analog digital converter ADC, respectively. Delay means (1H delay element) 1HD for one horizontal scanning period by the digital memory of
L, one inverter INV, and one adder ADD
And a vertical contour emphasis signal generation section 44 in the vertical contour emphasis apparatus illustrated in FIG. 3 is configured to generate a vertical contour emphasis signal in the form of a digital signal. Two constituent parts 44a,
44b each have the same frequency and a phase of 1
After being operated by clock signals (pulses) different by 80 degrees, the vertical contour signals of the digital signals simultaneously output from the two component parts 44a and 44b are converted into serial signals by the latch circuit LAT, and then, It is converted into an analog signal by the digital-analog converter DAC and supplied to the adder 42.

That is, in the vertical contour emphasizing apparatus illustrated in FIG. 3, the frequency band of the signal to be processed by the vertical contour signal generator 44 by the low-pass filter 34 is, for example, the frequency band of the main line signal. After being limited to a frequency band of 1/4 of the above, the two component parts 44a and 44b are respectively supplied to the analog-digital converters ADC provided therein. , 44b are respectively supplied with sampling signals (pulses) having the same frequency and phases different from each other by 180 degrees from the analog-digital converters ADC respectively provided. The analog-digital converter ADC provided in each of the two constituent portions 44a and 44b is provided in the vertical contour signal generation unit 44 as described above. Components 44a, when 44b is had only provided one, one sampling signal to be supplied to the analog-to-digital converter ADC (pulse)
Since it is possible to operate with a pulse having a period of 1/2 that of the above, the vertical contour emphasizing device illustrated in FIG. , Compared with the clock signal required for digital signal processing, (1/4) × (1/2)
This means that it can operate with a clock signal having a repetition frequency of = 1/8.

That is, in the vertical contour emphasizing apparatus illustrated in FIG. 3, as the clock signal required for digital signal processing, a clock signal having a repetition frequency of ⅛ as compared with the conventional apparatus can be used. Therefore, as described above, for example, when the video signal having the maximum horizontal scanning frequency has a horizontal scanning frequency of 90 KHz and the number of pixels is 1500, for example, contour enhancement is applied to the video signal. In FIG. 3, the clock signal for digital signal processing used in the contour enhancement apparatus is required to have an extremely high frequency of about 150 MHz in consideration of the blanking period. In the illustrated vertical contour emphasis device, digital signal processing can be performed with a clock signal of 20 MHz having a frequency value of ⅛ of 150 MHz. It becomes door. And the above 20 MH
A digital circuit that operates with a clock signal of z can be inexpensively obtained as a general-purpose product that operates stably. Since the vertical contour enhancement signal does not affect the main line signal, a 6-bit resolution is sufficient for the analog-digital converter ADC used for generating the vertical contour enhancement signal.

By the way, when a plurality of analog-digital converters ADC are operated in parallel, vertical stripes are generally generated in a reproduced image based on the difference in linearity between the individual analog-digital converters ADC. However, like the vertical contour signal generator 44 shown in FIG. 3, two series of individual signals generated in the component portions 44a and 44b configured to generate the vertical contour emphasis signal in the form of a digital signal are used. Vertical contour enhancement signal in digital signal form,
For example, when the latch circuit LAT is used to convert the signals into serial signals, each component 4 is configured to generate the vertical contour emphasis signal in the digital signal form described above.
Regarding 4a and 44b, for example, when a white signal is considered, a signal having the same signal level as the signal before the 1H period and the current signal is subtracted by the adder ADD (one of the signals is inverted by the inverter INV and added). Therefore, the output of the adder becomes zero, so that vertical stripes do not occur even due to the difference in linearity of the analog-digital converter ADC provided in each of the above-mentioned constituent portions 44a and 44b. Therefore, there is no problem even if the number of components configured to generate the vertical contour enhancement signal in the form of a digital signal is increased.

By the way, in the case where the video signal to be subjected to the edge enhancement by the vertical edge enhancement apparatus illustrated in FIG. 3 has a frequency ratio of 6 times, such as a horizontal scanning frequency change range of 15 KHz to 90 KHz. When the clock signal is generated so that the frequency ratio of the clock signal used for digital signal processing in the vertical contour enhancement device also changes in the range of 6 times, the clock signal can be generated stably. The difficulties are as described above. The clock signal generation unit 45 shown in FIG. 4 is a configuration example of the clock signal generation unit 45 that does not cause the above problem. FIG. 4 is a block diagram showing a specific configuration example of the clock signal generator 45. In FIG. 4, HSEP is a horizontal sync separation circuit, and PLL is a phase locked loop.

Phase Locked Loop PLL
Is a phase comparison circuit PC, a low-pass filter LPF,
It is constituted by a closed loop of a voltage controlled oscillator VCO and a programmable counter (programmable frequency divider) PCUT. The frequency division ratio of the programmable counter (programmable frequency divider) PCUT in the phase-locked loop PLL is the horizontal scanning frequency (horizontal synchronization frequency) in the video signal targeted for edge enhancement in the vertical edge enhancement device. Corresponding to, the division ratio data generator 4 for generating division ratio data
6 through the data bus 47, the frequency division ratio data given to the programmable counter (programmable frequency divider) PCUT.

The above-mentioned frequency division ratio data generator 46 is shown in FIG.
The configuration of the switching signal generator 27 described above with reference to FIG. 8 can be used. In other words, the frequency division ratio data generation unit 46 uses the horizontal synchronization signal that separates the horizontal synchronization signal from the composite synchronization signal of the video signal that is supplied through the input terminal 45b of the clock signal generation unit 45 and is the target of the edge enhancement. Separation circuit (corresponds to the horizontal synchronization separation circuit 30 in FIG. 2 .... The clock signal generation unit 45 depends on the configuration of the synchronization separation circuit provided in the division ratio data generation unit 46.
The video signal to be subjected to contour enhancement may be supplied via the input terminal 45b of the above) and the horizontal sync separation circuit (corresponding to the horizontal sync separation circuit 30 in FIG. 2). A frequency-voltage converter that outputs an output signal having a voltage value corresponding to the frequency of the horizontal synchronizing signal (corresponding to the frequency-voltage converter 31 in FIG. 2), and an analog that converts the output voltage from the frequency-voltage converter into a digital signal. A digital converter (corresponding to the analog-digital converter 32 in FIG. 2) and digital data indicating the frequency of the horizontal synchronizing signal in the video signal targeted for contour enhancement output from the analog-digital converter are given. Frequency division ratio data generator (for example, frequency division ratio data generator configured using a microcomputer ... Corresponding to the switching signal generator 33 in FIG. 2) Or it may be what was.

When the digital data indicating the frequency of the horizontal synchronizing signal in the video signal targeted for contour enhancement is given to the above-mentioned frequency division ratio data generator, the correspondence relation between each column in "Table 2" is given. Data having a predetermined frequency division ratio indicated by is given to the programmable counter (programmable frequency divider) PCUT via the transmission line 47.

[0049]

[Table 2]

In the configuration example shown in FIG. 3, the numerical value shown in the column of 1H delay element (number of pixels) in "Table 2" is 1/2. The values shown in the column of the frequency range of the clock signal in "Table 2" are shown in FIG.
The case of the configuration example shown in FIG. In the 1H delay element (the number of pixels) shown in "Table 2", the frequency band of the signal to be processed by the vertical contour signal generation unit 44 is 1/4 of the frequency band of the main line signal. The value is limited so that Assuming a horizontal 1500-pixel video signal, the minimum number of pixels is about 400 in this case. Therefore, assign it to the frequency range of the horizontal sync signal in the video signal that is the target of edge enhancement,
Further, "Table 2" shows an example in which the change range of the frequency of the clock signal used for digital signal processing is set to be small.

The 1H delay element (number of pixels) shown in "Table 2" is equal to the frequency division ratio of the programmable counter (programmable frequency divider) PCUT, and corresponds to the frequency division ratio described above. The frequency values shown in the column of the variation range of the frequency of the clock signal in "Table 2" are obtained. The range of the frequency value shown in the column of the range of change of the frequency of the clock signal in "Table 2" is about 1.5 at the maximum, but this ratio of 1.5 shows that the range of change of the horizontal scanning frequency is 1
1/4 compared to 6 times at a frequency ratio of 5 KHz to 90 KHz
Therefore, as compared with the case where the clock signal is generated so that the frequency ratio of the clock signal used for digital signal processing changes in the range of 6 times, the clock signal should be generated in a stable state. It is easy to see that you can. The clock signal generated by the clock signal generator 45 is supplied to the vertical contour signal generator 44 through the transmission line 45d, and the clock signal generated by the clock signal generator 45 is transmitted by the transmission line 45d. The address signal supplied to the vertical contour signal generation unit 44 via 45d is supplied to the delay means (1H delay element) 1HDL etc. of one horizontal scanning period by the digital memory in the vertical contour signal generation unit 44 via the address bus 45c. To be done.

Also in the vertical contour emphasizing apparatus illustrated in FIG. 3, after the video signal between the adjacent horizontal scanning lines is used based on the detection result of the horizontal scanning period of the video signal targeted for the contour emphasis. The pulse repetition frequency value for operating the digital signal processing circuit for performing the vertical contour enhancement operation of the video signal by edge enhancement is predetermined with respect to the horizontal synchronization frequency value in the video signal targeted for contour enhancement. The scaling factor for setting a frequency value of an integral multiple is automatically switched in conjunction with the switching operation of the horizontal contour emphasis circuit of the video signal described above. The horizontal sync frequency of the target video signal is set to a frequency value of a specific scaling factor, and the division ratio is the water content of the target video signal for contour enhancement. Corresponds to the synchronization frequency is generated by a predetermined configured to include a programmable counter PCUT in FIG set to be that value was phase-locked loop PLL. Of course, in carrying out the present invention, a contour emphasizing signal generating means for generating the contour emphasizing signal by second-order differentiation of the video signal may be used.

[0053]

As is apparent from the above description in detail, the contour enhancement apparatus for video signals according to the present invention, when a plurality of video signals having different horizontal scanning standards are targeted for contour enhancement, The frequency range of the horizontal synchronizing frequency in the video signal is divided into a plurality of predetermined frequency regions, and the horizontal contour emphasis frequency set individually for each frequency region obtained by the division is used as a target of contour emphasis. A horizontal scanning standard of the video signal which is the target of the contour enhancement, by providing an individual horizontal contour enhancement means configured to perform the horizontal contour enhancement for the video signal being enhanced for each frequency region. Correspondingly, switching is performed so that a predetermined one of the horizontal contour emphasizing means provided for each of the above-mentioned frequency regions is used, and for each of the above-mentioned frequency regions. A vertical contour emphasizing means for a plurality of video signals, which is configured to include a delay means having a specific delay time, and which performs vertical contour emphasizing operation of the video signal by trailing edge enhancement using video signals between adjacent horizontal scanning lines. Interlocking with the switching operation of the horizontal contour emphasizing means of the video signal, switching is performed so that a corresponding predetermined one of the vertical contour emphasizing means of the video signal provided for each frequency region is used. Therefore, the contour enhancement operation for a plurality of video signals having different horizontal scanning standards can be easily realized by the contour enhancement device for video signals having a simple configuration, and the horizontal scanning standards are different. In order to be able to perform contour enhancement operation for multiple video signals,
The frequency range of the horizontal synchronizing frequency in the video signal targeted for contour enhancement is divided into a plurality of predetermined frequency regions, and the horizontal contour enhancement is set individually for each of the divided frequency regions. In frequency, for each frequency region obtained by the above division, horizontal contour enhancement is performed for an analog signal form video signal,
By the horizontal contour emphasis frequency set individually,
A video signal targeted for contour enhancement is provided for each of the frequency regions by providing individual horizontal contour enhancement means configured to perform horizontal contour enhancement for the video signal targeted for contour enhancement. Corresponding to the horizontal scanning standard of, the horizontal contour enhancement circuit for the analog video signal provided for each frequency region described above is based on the detection result of the horizontal scanning cycle performed for the video signal targeted for contour enhancement. Corresponding predetermined ones are used among the horizontal contour emphasizing circuits for analog video signals provided for each of the above-mentioned frequency regions in correspondence with the horizontal scanning standard of the video signal targeted for contour emphasizing. The above-mentioned frequencies obtained by dividing the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions. Digital signal processing for performing vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines which is performed on a video signal in a digital signal form in a predetermined state set individually for each region As a circuit, only one set of a vertical contour signal generating means for a video signal by trailing edge enhancement, which is configured by using an analog-digital converter, a delay means for one horizontal scanning period by a digital memory, and an adding means, is used. When the digital signal processing circuit of the configuration mode is used, the vertical contour signal of the video signal output from the vertical contour signal generating means is
The digital signal is converted into an analog signal by the digital-analog converter and output, and the digital signal having the above-described structure for performing the vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal between the adjacent horizontal scanning lines. The pulse repetition frequency for operating the signal processing circuit is based on the detection result of the horizontal scanning cycle of the video signal targeted for contour enhancement, and is based on the horizontal synchronization frequency value in the video signal targeted for contour enhancement. Between the adjacent horizontal scanning lines by automatically switching the magnification for setting a frequency value of a predetermined integral multiple by interlocking with the switching operation of the horizontal contour emphasis circuit of the video signal described above. The digital signal processing circuit having the configuration for performing the vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal is performed by the digital signal processing circuit. Adjacent horizontal scanning performed on a video signal in a digital signal form in a predetermined state set individually for each of the above-mentioned frequency regions obtained by dividing the frequency range of the synchronization frequency into a plurality of predetermined frequency regions. The vertical edge enhancement operation of the video signal by the trailing edge enhancement using the video signal between lines is favorably performed, and the frequency range of the horizontal synchronizing frequency of the video signal is set to a plurality of predetermined frequency regions. For each of the above-mentioned frequency regions obtained by division, the video signal by the trailing edge enhancement using the video signal between the adjacent horizontal scanning lines which is performed for the video signal in the digital signal form in the individually set predetermined state As a digital signal processing circuit that performs vertical contour enhancement operation,
For a video signal in the form of a digital signal in a predetermined condition set individually for each of the above-mentioned frequency regions obtained by dividing the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions. Analog-to-digital converter in a digital signal processing circuit for performing vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines, delay means for one horizontal scanning period by digital memory, and adding means In the case of a digital signal processing circuit having a configuration in which a plurality of means for generating a vertical contour signal of a video signal by trailing edge enhancement configured by using Each of the generating means is operated with a pulse (clock signal) having the same frequency but different phases from each other, whereby The vertical contour signals of the video signals simultaneously output from the means for generating the vertical contour signals of the video signal by edge enhancement are converted into serial signals by, for example, a latch circuit, and then converted into analog signals by a digital-analog converter. Based on the detection result of the horizontal scanning cycle of the video signal targeted for edge enhancement, the vertical of the video signal by the trailing edge enhancement using the video signal between adjacent horizontal scanning lines. Set the pulse repetition frequency value that operates the digital signal processing circuit for performing the edge enhancement operation to a frequency value that is a predetermined integer multiple of the horizontal synchronization frequency value of the video signal that is the object of edge enhancement. The magnification for automatically switching in conjunction with the switching operation of the above-mentioned horizontal contour emphasis circuit for the video signal, and the pulse is repeated. The frequency value is set to the frequency value of a specific scaling factor of the horizontal synchronization frequency in the video signal targeted for contour enhancement, and the frequency division ratio is set to the horizontal synchronization in the video signal targeted for contour enhancement. The horizontal synchronization frequency is distributed over a wide frequency range by being generated by a phase locked loop including a programmable counter set to a predetermined value corresponding to the frequency. In such a state, even if a plurality of types of video signals having different scanning standards are supplied as the video signals targeted for contour enhancement, the video signals are supplied in advance according to the horizontal synchronizing frequency of the supplied video signals. About the frequency range of the horizontal synchronizing frequency in the video signal Set for a predetermined frequency range in the frequency range that was divided into multiple frequency ranges The optimum contour enhancement operation is automatically switched so that the contour enhancement operation is performed without performing signal processing that adversely affects the main line signal. Therefore, a video signal having good characteristics is obtained, and a vertical contour signal of the video signal is generated by the trailing edge enhancement constituted by a delay unit for one horizontal scanning period by a digital memory and an adding unit. A plurality of sets of means are provided, and each of the means for generating the vertical contour signal of the video signal by the trailing edge enhancement is operated by pulses having the same frequency but different phases, and digital signal processing is performed in parallel. Since it is processed, the frequency of the clock signal for digital processing and the resolution can be lowered, so that a stable device can be provided stably. Furthermore, since the frequency range of the clock signal for digital signal processing can be narrowed despite the wide variation range of the horizontal synchronizing frequency, the device can be operated in a stable state. According to the present invention, it is possible to provide a contour enhancement apparatus for a video signal which does not have various problems in the above-described conventional apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram of a contour enhancement apparatus for video signals according to the present invention.

FIG. 2 is a block diagram of a part of the configuration of a contour enhancement apparatus for video signals according to the present invention.

FIG. 3 is a block diagram of a contour enhancement apparatus for video signals according to the present invention.

FIG. 4 is a block diagram of a part of a configuration of a video signal contour enhancement apparatus of the present invention.

FIG. 5 is a block diagram of a conventional contour enhancement device.

FIG. 6 is a block diagram of a conventional contour enhancement device.

FIG. 7 is a block diagram of a conventional contour enhancement device.

FIG. 8 is a block diagram of an example configuration of a vertical contour enhancement device.

[Explanation of symbols]

1 ... an input terminal of a video signal which is a target of contour enhancement,
2 ... Output terminal of video signal with contour enhancement, 3, 4,
3a, 3b, 3c, 4a, 4b, 4c, 9, 16-1
9, 36 to 39 ... Delay element, 3G, 4G ... Delay element group,
5-7,10,11,20-24 ... Coefficient unit, 8,12,
25 ... Adder, 13, ADC ... Analog-digital converter, 14, 15 ... Delay element for giving time delay of one horizontal scanning period to digital video signal, 26 ... DAC ... Digital-analog converter, 27 ... Switching signal generating section, 30 ... Horizontal sync separation circuit, 31 ... Frequency-voltage converter, 32 ... Analog-digital converter, 33 ... Switching signal generator constituted by using microcomputer, 34 ... Low-pass filter, 35
... Delay elements for delay adjustment, 40, 41 ... Coefficient multiplier, 42
... Adder, 43, SW1, SW2 ... Changeover switch, 44 ...
Vertical contour signal generation unit, 45 ... Clock signal generation unit, 46
... division ratio data generator, 47 ... data bus, 1HDL ...
Delay means for one horizontal scanning period by digital memory (1H
Delay element), INV ... Inverter, ADD ... Adder, L
AT ... Latch circuit, DAC ... Digital-analog converter,
HSEP ... Horizontal sync separation circuit, PLL ... Phase locked loop, PC ... Phase comparison circuit, LPF ... Low pass filter, VCO ... Voltage controlled oscillator, PCUT ... Programmable counter (programmable frequency divider),

Claims (6)

[Claims] 1. A video signal contour enhancement apparatus capable of performing a contour enhancement operation on a plurality of video signals having different horizontal scanning standards, wherein the horizontal synchronization frequency of the video signal to be subject to contour enhancement is provided. The frequency range of is divided into a plurality of predetermined frequency regions, and the horizontal outline emphasis frequency that is individually set for each frequency region obtained by the division, for the video signal that is the target of outline emphasis. An individual horizontal contour emphasizing unit configured to perform horizontal contour emphasizing is provided for each of the frequency regions, and corresponds to the horizontal scanning standard of the video signal supplied so as to be the object of the contour emphasizing. A means for switching and using a predetermined one of the horizontal contour emphasizing means provided for each of the above frequency regions, and a special feature for each of the above frequency regions. A vertical edge enhancing means for a plurality of video signals, the vertical edge enhancing means for performing a vertical edge enhancing operation of a video signal by trailing edge enhancement using an image signal between adjacent horizontal scanning lines. Means for interlocking with the switching operation of the horizontal contour emphasizing means of the video signal described above so that a predetermined one of the vertical contour emphasizing means of the video signal provided for each frequency region is switched and used. And a contour enhancement device for a video signal. 2. A frequency range of a horizontal synchronizing frequency in a video signal targeted for contour enhancement is predetermined so that a contour enhancement operation can be performed on a plurality of video signals having different horizontal scanning standards. Horizontal contour enhancement is performed on a video signal in an analog signal form, which is a target of contour enhancement, at a horizontal contour enhancement frequency that is divided into a plurality of frequency regions and is set individually for each frequency region obtained by the division. An individual horizontal contour emphasizing circuit configured to be capable of performing is provided for each of the frequency regions, and in correspondence with the horizontal scanning standard of the video signal supplied to be the target of contour emphasizing, Means for switching and using a predetermined one of the horizontal contour emphasizing circuits for analog video signals provided for each frequency region, and adjacent horizontal scanning The vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal between lines divides the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions, and obtains each frequency region described above. A digital signal for performing vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines, as is performed for a video signal in a digital signal form in a predetermined state set for each As a processing circuit, an analog-digital converter, delay means for one horizontal scanning period by a digital memory, and means for generating a vertical contour signal of a video signal by trailing edge enhancement configured by adding means, and the trailing edge enhancement A digital-analog converter for converting the vertical contour signal of the video signal output from the vertical contour signal generating means of An image which is configured to include the above and which is provided with means for switching the repetition frequency of the pulse to a predetermined frequency value in conjunction with the switching operation of the horizontal contour enhancement circuit for the video signal. Signal contour enhancement device. 3. A frequency range of a horizontal synchronizing frequency in a video signal targeted for contour enhancement is predetermined so that a contour enhancement operation can be performed on a plurality of video signals having different horizontal scanning standards. Horizontal contour enhancement is performed on a video signal in an analog signal form, which is a target of contour enhancement, at a horizontal contour enhancement frequency that is divided into a plurality of frequency regions and is set individually for each frequency region obtained by the division. An individual horizontal contour emphasizing circuit configured to be capable of performing is provided for each of the frequency regions, and in correspondence with the horizontal scanning standard of the video signal supplied to be the target of contour emphasizing, Means for switching and using a predetermined one of the horizontal contour emphasizing circuits for analog video signals provided for each frequency region, and adjacent horizontal scanning The vertical contour enhancement operation of the video signal by the trailing edge enhancement using the video signal between lines divides the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions, and obtains each frequency region described above. A digital signal for performing vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines, as is performed for a video signal in a digital signal form in a predetermined state set for each As a processing circuit, a plurality of sets of a vertical contour signal generating means for a video signal by trailing edge emphasis configured by using an analog-digital converter, a delay means for one horizontal scanning period by a digital memory, and an adding means are provided.
Means for operating each of the means for generating the vertical contour signal of the video signal by the trailing edge enhancement with a pulse having the same frequency and different phases from each other; It is configured to include means for converting vertical contour signals of video signals simultaneously output from the means for generating vertical contour signals into serial signals, and a digital-analog converter for performing digital-analog conversion of the serial signals and outputting the serial signals. And a means for switching the repetition frequency of the pulse to a predetermined frequency value in conjunction with the switching operation of the horizontal contour emphasizing circuit for the video signal described above. Emphasis device. 4. A frequency range of a horizontal synchronizing frequency in a video signal targeted for contour enhancement is predetermined so that a contour enhancement operation can be performed on a plurality of video signals having different horizontal scanning standards. It is divided into a plurality of frequency regions, and horizontal contour enhancement can be performed on an analog video signal at a horizontal contour enhancement frequency set individually for each frequency region obtained by the division. An individual horizontal contour emphasizing circuit is provided for each frequency region, and each frequency region is provided corresponding to the horizontal scanning standard of the video signal supplied so as to be the object of contour emphasizing. Means for switching and using a corresponding one of the horizontal contour enhancement circuits of the analog video signal, and using the video signal between adjacent horizontal scanning lines. The vertical contour enhancement operation of the video signal by the edge enhancement is performed by dividing the frequency range of the horizontal synchronizing frequency of the video signal into a plurality of predetermined frequency regions and individually setting the predetermined frequency regions. An analog-to-digital converter is used as a digital signal processing circuit for performing a vertical contour enhancement operation of a video signal by trailing edge enhancement using a video signal between adjacent horizontal scanning lines, as is performed for a video signal in a digital signal form in the above state. , A plurality of sets of vertical contour signal generating means for the trailing edge emphasizing video signal, which are constituted by a delay means for one horizontal scanning period by a digital memory and an adding means, are provided. Each of the means for generating the contour signal,
A serial signal is a vertical contour signal of a video signal that is simultaneously output from the means for generating a vertical contour signal of a video signal by a plurality of trailing edge enhancements, which are operated by pulses having the same frequency but different phases. With the configuration to output after digital-analog conversion after conversion to, set the repetition frequency value of the pulse to the frequency value of a specific magnification of the horizontal synchronizing frequency in the video signal that is the object of contour enhancement, The pulse is generated by a phase-locked loop including a programmable counter, and the frequency division ratio of the programmable counter corresponds to the horizontal synchronizing frequency in the video signal targeted for contour enhancement. A contour enhancement device for a video signal configured to be set to a predetermined value. 5. A frequency of a horizontal synchronizing frequency in a video signal, which corresponds to the horizontal scanning cycle of the detected video signal and which detects the horizontal scanning cycle of the video signal supplied so as to be a target of contour enhancement. 5. The video signal contour enhancement apparatus according to claim 1, wherein the horizontal contour enhancement frequencies individually set for the respective frequency regions obtained by dividing the range are automatically switched. . 6. A video signal between adjacent horizontal scanning lines, which detects a horizontal scanning cycle of a video signal supplied so as to be an object of contour enhancement, and which corresponds to the horizontal scanning cycle of the detected video signal. The repetition frequency value of the pulse for operating the digital signal processing circuit that performs the vertical edge enhancement operation of the video signal by the trailing edge enhancement using is determined in advance with respect to the horizontal synchronization frequency value of the video signal targeted for edge enhancement. 5. A contour enhancement apparatus for a video signal according to claim 3, wherein a scaling factor for setting the frequency value of the obtained integral multiple is automatically switched.