JP2002369016A - Image reading system and control program for image reading system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an image reading system that automatically determines the type of a film and performs an appropriate process according to the type. An image reading system includes an image scanner and a personal computer (PC). The PC executes the control program, first causes the image scanner to color-scan the transmitted light image of the film, and outputs negative image data representing the characteristic values of each of the RGB colors which are weighted independently and color by color of the transmitted light image (S11). ), A histogram for the characteristic values of each of the RGB colors is generated as frequency distribution data based on the negative image data output from the image scanner (S1).
2), the type of the film is determined based on the generated frequency distribution data (S15). Output positive image data representing the characteristic value of each color of RGB not weighted for each (S
18).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an image reading system and a control program for the image reading system.

[0002]

2. Description of the Related Art Conventionally, as a system for reading a document image recorded on a document, an image reading system including an image reading unit such as an image scanner and an image processing unit such as a personal computer (hereinafter referred to as a PC) is known. Have been. In such an image reading system, when reading various films such as a positive film, a color negative film, and a monochrome negative film, different processes are performed according to the type of the film. For example, a negative film has the property that B (Blue) light among the three primary color lights is most difficult to transmit. Therefore, when reading a negative film, the exposure time of the image sensor and the amplification factor of the output signal of the image sensor are particularly related to the B light. Become

Therefore, in order to perform an appropriate process for each film to be read in the image reading system, it is essential to specify the type of the film before reading the film. Therefore, conventionally, the type of the film is determined based on information input by the user to the image processing unit.

[0004]

However, since the conventional method of discriminating the type of film largely depends on artificial processing, if a user inputs the film type incorrectly, the image recorded on the film is deleted. Reading cannot be performed properly. The occurrence of such a situation contrary to the user's intention is not preferable because it leads to a decrease in the reliability of the image reading system.

[0005] The present invention has been made in view of the above problems, and has as its object to provide an image reading system that automatically discriminates the type of a film and performs appropriate processing according to the type. is there. It is another object of the present invention to provide a control program for an image reading system that allows a computer to automatically determine the type of a film to be read and execute an appropriate process according to the type.

[0006]

According to the first aspect of the present invention, the imaging means performs color scanning of the transmitted light image of the film by photoelectric conversion, and independently weights the three colors of the transmitted light image for each color. Negative image data representing characteristic values or positive image data representing characteristic values of three colors of the transmitted light image that are independent of each other and are not weighted for each color are output, and the first processing unit outputs the negative image data to the imaging unit. The frequency distribution data representing the frequency distribution of the characteristic value is output based on the output negative image data, the second processing means determines the type of the film based on the frequency distribution data, and the third processing means The negative image data or the positive image data is output to the imaging means according to the type of the film.

According to the first aspect of the present invention, the frequency distribution data output by the first processing means based on the negative data represents a unique frequency distribution for each film type. The type of film can be accurately determined based on the frequency distribution data. Further, according to the first aspect of the invention, the third processing means causes the imaging means to output one of the negative image data and the positive image data suitable for the type of film determined by the second processing means. Therefore, according to the first aspect of the present invention, it is possible to provide an image reading system that automatically determines the type of a film and performs an appropriate process according to the type. The “color characteristic value” described in the claims is, for example, 3 representing the property of the color stimulus value.
The stimulus value of the primary color, and the “film type” includes, for example, a positive film, a color negative film, and a monochrome negative film.

According to the second aspect of the present invention, the second processing means determines the type of the film in accordance with the degree of deviation of the frequency distribution of the characteristic values of the weighted colors of the transmitted light image, whereby the positive type is determined. Film can be accurately identified. Incidentally, the "bias of the frequency distribution" described in the claims is, for example, using the cumulative frequency of a predetermined section in each frequency distribution, a median value, a mode, an average value, a central class value in a predetermined distribution range, and the like. Can be specified.

According to the third aspect of the present invention, the three independent colors are composed of R (red), G (green) and B (blue), and the second processing means performs R (R) for the transmitted light image. When the frequency distribution of the characteristic value of B is biased to a value larger than the frequency distribution of the characteristic value of B, the film is determined to be a color negative film, and the frequency distribution of the characteristic value of B is larger than the frequency distribution of the characteristic value of R. When the value is biased, it is determined that the film is a monochrome negative film. Therefore, according to the third aspect of the invention, the film is a color negative film or a monochrome negative film by focusing on the relative bias between the frequency distribution of the characteristic value of B and the frequency distribution of the characteristic value of R. Can be accurately determined.

According to the fourth aspect of the present invention, the image pickup means performs color scanning of the transmitted light image of the film by photoelectric conversion, and weights R (red) and G weighted for each color of the transmitted light image.
Negative image data representing characteristic values of (green) and B (blue) or positive image data representing characteristic values of R, G, and B not weighted for each color of the transmitted light image; The positive image data is output to the imaging unit, and based on the output positive image data, frequency distribution data representing a frequency distribution of R, G, and B characteristic values is output, and the second processing unit is configured to output the frequency distribution data based on the frequency distribution data. The type of the film is determined, and the third processing unit causes the imaging unit to output the negative image data or the positive image data according to the type of the film.

According to the fourth aspect of the present invention, the frequency distribution data output from the first processing means based on the positive image data represents a unique frequency distribution for each film type. The type of film can be accurately determined based on the frequency distribution data. Further, according to the invention according to claim 4, the third processing means causes the imaging means to output one of the negative image data and the positive image data suitable for the type of film determined by the second processing means. Therefore, according to the invention according to claim 4, the type of the film is automatically determined by a configuration different from the invention according to any one of claims 1 to 3, and an appropriate process is performed according to the type. An image reading system can be provided.

According to the fifth aspect of the invention, the second processing means sets the type of the film according to the degree of correlation between the frequency distribution of the characteristic value of B and the frequency distribution of the characteristic value of R for the transmitted light image. By making the determination, the positive film can be accurately determined. According to the invention according to claim 6, the second processing means further determines the type of the film according to the degree of deviation of the frequency distribution of the characteristic value of R with respect to the frequency distribution of the characteristic value of B for the transmitted light image. This makes it possible to accurately determine whether the film is a positive film or a color negative film.

According to the seventh aspect of the present invention, the second processing means further controls the film to be positive according to the degree of deviation of the frequency distribution of the characteristic value of R from the frequency distribution of the characteristic value of B in the transmitted light image. It is determined that the film is a film or a negative film. Then, when the second processing means determines that the film is a negative film, the second processing means further determines the transmission light image according to the degree of correlation between the frequency distribution of the characteristic values of G and the frequency distribution of the characteristic values of B with respect to the transmitted light image. It is determined that the negative film is a color negative film or a monochrome negative film. Therefore, according to the invention of claim 7, B
By paying attention to the relative deviation between the frequency distribution of the characteristic value of R and the frequency distribution of the characteristic value of R, it is possible to accurately determine the positive film, and further, the frequency distribution of the characteristic value of G and the frequency distribution of the characteristic value of B By paying attention to the degree of correlation with, it is possible to accurately determine whether the film is a color negative film or a monochrome negative film.

According to an eighth aspect of the present invention, in the first scanning control procedure, the computer for controlling the image pickup means of the image reading system for scanning an optical image by photoelectric conversion performs color scanning of the transmitted light image of the film on the image pickup means. Then, negative image data representing characteristic values of three colors weighted independently for each color of the transmitted light image is output, and in the first processing procedure, the characteristic values of the three colors are calculated based on the negative image data output by the imaging unit. A frequency distribution data representing a frequency distribution is output, a type of the film is determined based on the frequency distribution data in a second processing procedure, and a transmission of the film to the imaging unit is performed according to the type of the film in a second scanning control procedure. The light image is scanned in color and the negative image data or the transmitted light image is independent of each other and is not weighted for each color.
Outputs positive image data representing color characteristic values.

According to the present invention, the frequency distribution data output to the computer based on the negative image data represents a frequency distribution unique to each film type. Can be accurately determined. Also,
According to the invention of claim 8, the computer causes the image pickup means to output one of the negative image data and the positive image data suitable for the film type determined in the second processing procedure. Therefore, according to the invention according to claim 8, it is possible to provide a control program for an image reading system that causes a computer to automatically determine the type of a film to be read and execute an appropriate process according to the type. According to the ninth aspect of the present invention, in the second processing procedure, the computer is caused to determine that the film is a positive film in accordance with the degree of deviation of the frequency distribution of the weighted color characteristic values of the transmitted light image. . Therefore, according to the ninth aspect of the present invention, the positive film can be accurately determined based on the same principle as that of the second aspect of the present invention.

According to the tenth aspect, the three independent colors are composed of R (red), G (green), and B (blue).
When the frequency distribution of the characteristic value of R for the transmitted light image is biased to a value larger than the frequency distribution of the characteristic value of B, the film is determined to be a color negative film, and the frequency distribution of the characteristic value of B is the characteristic of R. When the value is biased to a value larger than the frequency distribution of the value, the film is determined to be a monochrome negative film. Therefore, according to the tenth aspect, it is possible to accurately determine whether the film is a color negative film or a monochrome negative film by the same principle as the third aspect.

According to the eleventh aspect of the present invention, a computer for controlling an image pickup means of an image reading system for scanning an optical image by photoelectric conversion, in the first scanning control procedure, scans the transmitted light image of the film with the image pickup means by color scanning. R (red) not weighted for each color of the transmitted light image,
Positive data representing the characteristic values of G (green) and B (blue) are output, and in the first processing procedure, frequencies representing the frequency distribution of the characteristic values of R, G and B based on the positive data output by the imaging means Output the distribution data, determine the type of the film based on the frequency distribution data in the second processing procedure, and color-scan the transmitted light image of the film by the imaging unit according to the type of the film in the second scanning control procedure. Then, the positive image data or the negative image data representing the characteristic values of R, G and B weighted for each color of the transmitted light image are output.

According to the eleventh aspect of the present invention, the frequency distribution data output to the computer based on the positive image data represents a unique frequency distribution for each type of film. Can be accurately determined. According to the eleventh aspect of the present invention, the computer causes the image pickup means to output one of the positive image data and the negative image data suitable for the film type determined in the second processing procedure. Therefore, according to the eleventh aspect of the present invention, the computer automatically determines the type of the film to be read by a configuration different from that of the invention according to any one of the eighth to tenth aspects, and an appropriate type corresponding to the type is read. It is possible to provide a control program of the image reading system that executes the processing.

According to the twelfth aspect of the present invention, in the second processing procedure, the computer is provided to the computer in accordance with the degree of correlation between the frequency distribution of the characteristic value of B and the frequency distribution of the characteristic value of R for the transmitted light image. The film is determined to be a positive film. Therefore, according to the invention of claim 12, according to the same principle as the invention of claim 5,
Positive film can be accurately identified.

According to a thirteenth aspect of the present invention, in the second processing procedure, the computer further controls the computer in accordance with the degree of deviation of the frequency distribution of the R characteristic value with respect to the frequency distribution of the B characteristic value for the transmitted light image. The film is determined to be a positive film or a color negative film. Therefore, according to the thirteenth aspect, it is possible to accurately determine whether the film is a positive film or a color negative film by the same principle as that of the sixth aspect.

According to a fourteenth aspect of the present invention, in the second processing procedure, the computer further controls the computer in accordance with the degree of deviation of the frequency distribution of the characteristic value of R with respect to the frequency distribution of the characteristic value of B for the transmitted light image. The film is determined to be a positive film or a negative film. And
In the second processing procedure, when the computer determines that the film is a negative film, the computer further determines, in accordance with the degree of correlation between the frequency distribution of the characteristic values of G and the frequency distribution of the characteristic values of B with respect to the transmitted light image. The computer determines that the negative film is a color negative film or a monochrome negative film. Therefore, claim 14
According to the present invention, it is possible to accurately determine whether the film is a positive film, a color negative film, or a monochrome negative film, based on the same principle as that of the seventh aspect.

According to the fifteenth aspect, the eighth aspect is provided.
15. A control program for the image reading system according to any one of the above-described items. Therefore, claim 1
According to the fifth aspect, the same effects as those of the invention according to any one of the eighth to fourteenth aspects can be obtained.

[0023]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 2 shows an image reading system 10 according to one embodiment of the present invention. The image reading system 10 includes the image scanner 1
1 and the PC 150.

As shown in FIG. 3, the image scanner 11 is of a so-called flat bed type having a document table 14 on an upper surface of a housing 12 having a generally box shape. Image scanner 1
Reference numeral 1 denotes an image sensor 20, an optical system 30 that forms a document image on the image sensor 20, a processing unit 100 that processes an output signal of the image sensor 20, and a driving unit 40 that drives the image sensor 20.
And a control unit 110.

The platen 14 is formed of a transparent plate such as a glass plate, and various kinds of films such as a positive film, a color negative film and a monochrome negative film, or reflection originals such as printing paper and photographic paper are placed on a board surface 15 thereof. Is done. The film is positioned on the board surface 15 of the document table 14 by the film holder 17. As the film holder 17, for example, as shown in FIGS. 3 and 4, one having a generally rectangular flat plate shape and having a film window 60 penetrating in a thickness direction thereof and a transparent reference white window 62 is used. The film holder 17 is positioned along the document guide 16 on the board surface 15 of the document table 14 with its back surface 18 facing downward.
The reflection document is moved by the document guide 16 to the surface 15 of the platen 14.
Is positioned on top. A white reference 28 for a reflective document having a high reflectance uniform reflection surface is provided at an edge of the document table 14.

Although a linear sensor is used for the image sensor 20, a contact type two-dimensional sensor may be used. The linear sensor 20 is mounted on the carriage 24 in such a manner that a plurality of photoelectric conversion elements are arranged substantially linearly in a direction perpendicular to a movement direction axis of the carriage 24 described later and parallel to the board surface 15 of the document table 14. A photodiode or the like is used as the photoelectric conversion element. The arrangement direction of the photoelectric conversion elements of the linear sensor 20 is the main scanning direction, and the moving direction of the carriage 24 (direction a in FIG. 3) is the sub-scanning direction. Linear sensor 2
As 0, visible light, infrared light, ultraviolet light, and the like, the electric charge obtained by photoelectrically converting light in a predetermined wavelength region is accumulated for a certain period of time,
A device that outputs an electric signal corresponding to the amount of received light using a CCD, a MOS transistor switch, or the like is used. In this embodiment, a lens-reduced linear image sensor is used as the linear sensor 20, but a contact-type linear image sensor may be used.

The color output system employs an on-chip system, and uses a three-line or six-line linear sensor 20 in which a color filter array is formed on-chip in a light receiving portion. The linear sensor 20 outputs an electric signal according to the arrangement state of the color filter array. As a color filter array, R (Red), G (G
reen) or B (Blue). The color output method may be any of a dichroic mirror method, a light source switching method, and a filter switching method. Also, C (Cyan), M (Magent
The color filter array may be composed of a) and three color filters of Y (Yellow), or a plurality of color filters may be arranged in one line.

Here, the linear sensor (CCD linear image sensor) 20 will be described in detail. The linear sensor 20 has a photoelectric conversion element, a shift gate, an analog shift register, and a charge-voltage converter, and operates as follows. (1) When light is received by each photoelectric conversion element, electric charges are accumulated in each photoelectric conversion element by photoelectric conversion. (2) The charge accumulated in the photoelectric conversion element is transferred to the analog shift register when the shift pulse is input to the shift gate by the main scanning drive unit 102 described later. This charge transfer is performed simultaneously for all the photoelectric conversion elements. The time for accumulating charges in the photoelectric conversion element, that is, the exposure time can be changed by changing the pulse interval of the shift pulse or by using the electronic shutter. (3) Based on the input of the transfer pulse to the analog shift register by the main scanning drive unit 102, the charges transferred to the analog shift register are transferred to the charge-voltage conversion unit. (4) The charge transferred to the charge-voltage converter is converted into a voltage signal.

An optical system 30 for forming a document image on the image pickup device 20 includes a light source 38 for a transmission document, a light source 22 for a reflection document, a mirror 34, a condenser lens 36 and the like.

In the housing 12, a transparent original unit 37 having a transparent original light source 38 is provided detachably.
The transparent original light source unit 37 is mounted on the housing 12 when reading a film, and is removed when reading a reflective original. In this embodiment, the light source 38 for the transparent original is
Tube illumination 39 such as a fluorescent tube lamp, diffuser plate 50 and reflecting member 5
2 is a surface light source. The illumination light of the tube illumination 39 is reflected directly or by the reflection member 52 and the diffusion plate 50
And is further diffused by the diffusion plate 50 and
The irradiation area on the board surface 15 of No. 4 is almost uniformly irradiated.
As shown by the broken line in FIG. 3, the transmitted light image of the film on the document table 14 illuminated by the transparent document light source 38 is converted into a linear sensor 2 by an optical system 30 such as a mirror 34 and a condenser lens 36.
It is imaged at 0. As the light source 38 for the transparent original, a light source in which the tube illumination 39 moves in the sub-scanning direction together with the main scanning line may be used.

A drive unit 40 for driving the linear sensor 20
Is composed of a main scanning drive unit 102 mainly operating electronically and a sub-scanning driving unit 26 mainly operating mechanically.
The main scanning drive unit 102 is an electronic circuit that generates drive pulses such as shift pulses and transfer pulses necessary for driving the linear sensor 20, and outputs the generated drive pulses to the linear sensor 20.
The main scanning drive unit 102 includes, for example, a synchronization signal generator, a drive timing generator, and the like. The sub-scanning drive unit 26 that moves the main scanning line in the sub-scanning direction includes a carriage 24, a belt locked to the carriage 24, and a stepping motor that rotates the belt, for example, is easily controlled. The carriage 24 is slidably engaged with a shaft or the like, and is provided so as to be reciprocally movable in a direction parallel to the board surface 15 of the document table 14. The carriage 24 conveys the linear sensor 20 in parallel with the board surface 15 of the document table 14 by, for example, belt driving.

As shown in FIG. 2, the processing section 100 includes an analog signal processing circuit 104, an A / D converter 106, and a digital signal processing section 108. In this embodiment, the analog signal processing circuit 104 and the A / D converter 106 of the processing unit 100 are mounted on the carriage 24 together with the main scanning drive unit 102, and the digital signal processing unit 108 is fixed on the housing 12 together with the control unit 110. Have been. The circuit mounted on the carriage 24 and the circuit fixed to the housing 12 are connected by a flexible flat cable (not shown).

The analog signal processing circuit 104 performs analog signal processing such as amplification and noise reduction processing on the analog electric signal output from the linear sensor 20 and sends the processed signal to the A / D converter 106. Output. Amplification in analog signal processing is, for example, preamplifier, auto
This is performed by a gain control circuit. The noise reduction processing is performed using, for example, a correlated double sampling method.

The A / D converter 106 quantizes the analog electric signal output from the analog signal processing circuit 104 into a digital image signal of a predetermined gradation, and outputs the image signal to the digital signal processing unit 108.

The digital signal processing unit 108 performs various processes on the image signal output from the A / D converter 106 and generates image data to be output to the PC 150.
Image data output from the digital signal processing unit 108 is transmitted to the PC 15 through an interface (I / F) 140.
0 is transferred. In this embodiment, the digital signal processing unit 1
The output of 08 is 8-bit, and the output image data is gradation data representing a stimulus value as a characteristic value for each of RGB colors (channels) in 256 gradation values from 0 to 255.

The digital signal processing unit 108 includes a shading correction unit 120 and a gamma correction unit 122
And a defective pixel correction unit 124. The shading correction unit 120 is caused by a variation in sensitivity for each pixel of the linear sensor 20 or for each block including several pixels, an irradiation light amount distribution in the main scanning direction of the light source 38 for the transparent original, an optical characteristic of the condenser lens 36, and the like. Correct shading. This shading correction is performed using white reference data acquired prior to scanning the original image by the linear sensor 20, or using the white reference data and a memory (for example, RO).
M134) is performed using the black reference data stored in advance. The white reference data is obtained by, for example, irradiating the light from the transparent original light source 38 when reading a film with the film holder 1.
7 through the white reference window 62 for the transparent original.
Can be obtained. The gamma correction unit 122 performs gamma correction of the image signal according to the gamma characteristics of the PC 150. The defective pixel correction unit 124 generates a signal of a defective pixel by interpolating a signal of a defective pixel with a signal of an adjacent pixel by a pixel interpolation method. Note that various processes performed by the digital signal processing unit 108 can be replaced with processes by a computer program executed by the control unit 110 or the PC 150.

The control unit 110 includes a CPU 130 and a RAM 13
2 and a ROM 134. CPU 130 is PC15
By executing various computer programs stored in the ROM 134 on the basis of the command signal from 0, the operation control of the linear sensor 20 (that is, the main scanning drive unit 10
2), control of the movement of the carriage 24 (ie, control of the operation of the sub-scanning drive unit 26),
Flashing and light amount control, operation control of the processing unit 100, etc.
The entire image scanner 11 is controlled. RAM 132
Temporarily stores an image signal processed by the digital signal processing unit 108, image data generated by the digital signal processing unit 108, and the like.

The image scanner 11 is connected to a PC 150 via an interface 140 provided on the housing 12.
Is electrically connected to The PC 150 includes a computer main body 152 to which the image scanner 11 is connected, and a C
It is composed of a monitor 154 such as an RT and an LCD, and an input device 156 such as a mouse and a keyboard. The computer main body 152 includes a CPU 160 and a storage unit 162 including a ROM, a RAM, a hard disk, and the like. CP
The U 160 controls the monitor 154 and the input device 156 by executing a computer program such as a film control program installed in the storage unit 162, and transmits a command signal for operating each element of the image scanner 11 to the control unit 110. I do. The control unit 110
Operates the respective elements of the image scanner 11 based on the received command signal. Therefore, the transmission of the command signal for operating the respective elements of the image scanner 11 to the control unit 110 by the CPU 160 means that the CPU 160 directly controls the respective elements. It is apparently equivalent to operating with Therefore, in the following, "transmitting a command signal for operating each element of the image scanner 11 to the control unit 110" will be described as "operating each element of the image scanner 11" for convenience.

The above-described film control program is an example of the “image reading system control program” described in the claims. The control program for film is
The information is provided by being recorded on a computer-readable recording medium such as a flexible disk, a CD-ROM, and a magneto-optical disk (MO), and is installed in the storage unit 162 and used. Thus, the recording medium on which the film control program is recorded and the storage unit 162 each constitute an example of the “recording medium” described in the claims. The film control program may be provided through an electric communication line such as the Internet. In this case, the film control program is stored in a storage device such as a server computer accessible by the PC 150. At this time, the storage device is an example of a “recording medium” described in the claims.

In the film control program, the user mounts the transparent document unit 37 on the housing 12, sets a desired film on the document table 14, and inputs an execution start command of the film control program via the input device 156. Executed in response to And as a result of the execution, C
The PU 160 sequentially performs each processing step shown in FIG. Specifically, first, step S11 (hereinafter simply referred to as S1
One. The same applies to other steps. )so,
The transmitted light image of the film is scanned by the linear sensor 20 while the transparent original light source 38 is turned on and the carriage 24 is moved at a constant speed. Further, an output signal of the linear sensor 20 that scans the transmitted light image is processed by the processing unit 110 to generate image data, and the image data is transferred to the PC 150 and stored in the storage unit 162. In this embodiment, this S11
The reading resolution of the transmitted light image at 100
By setting dpi, the reading speed of the transmitted light image is increased.

In step S11, the linear sensor 2
The scanning of the transmitted light image by 0 is performed in a predetermined scan mode of the negative mode and the positive mode. In this embodiment, the scan mode is selected in advance by a user input from the input device 156, but may be fixed to one of the negative mode and the positive mode. Here, the negative mode is a mode in which the charge accumulation time of each photoelectric conversion element of the linear sensor 20 is made different according to the color of the color filter corresponding to each photoelectric conversion element in order to scan a normal negative film. In the example, the charge accumulation time of the photoelectric conversion element corresponding to each of the RGB color filters is set to be 1: 2: 3 in length ratio. In the negative image data, which is image data obtained in such a negative mode, RGB values are weighted at 1: 2: 3 for each pixel. On the other hand, the positive mode is a mode in which the charge accumulation time of each photoelectric conversion element of the linear sensor 20 is made constant regardless of the color of the color filter in order to scan a normal positive film. That is, the positive image data, which is image data obtained in the positive mode, is not weighted for each of the RGB values. Note that, in order to obtain image data in which each value of RGB is weighted for each pixel, as described above, the linear sensor 2 is used.
In addition to adjusting the charge accumulation time of 0, for example, the analog signal processing circuit 104 may make the amplification factors of the output signals of the RGB channels different from each other. Further, the weighting coefficients are not limited to the above values.

In step S12, a frequency distribution data generation routine is executed to generate frequency distribution data necessary for identifying a film from the image data in the storage unit 162.

As shown in FIG. 5, in S31 of the frequency distribution data generation routine, the luminance value of each pixel is extracted from the image data in the storage unit 162 to generate a luminance histogram.
FIG. 6 shows an example of this luminance histogram. As shown in the figure, pixels corresponding to the back surface 18 of the film holder 17 are accumulated in a low luminance value range (for example, 0 to 30), and a film is mounted in a high luminance value range (for example, 225 to 255). Pixels corresponding to the background of the film holder 17 such as the film window 60 that are not processed are accumulated, and pixels corresponding to the film mounted on the film window 60 are distributed in a range of other luminance values. Hereinafter, a pixel region corresponding to the back surface 18 of the film holder 17 is referred to as a film holder region, a pixel region corresponding to the background of the film holder 17 is referred to as a background region, and a pixel region corresponding to the film is referred to as a film region.

In the luminance histogram, the boundary luminance value between the film region and the background region is determined by the film holder 1.
7 can be set to a constant value irrespective of the type of the film holder 17, but the boundary luminance value between the film holder area and the film area greatly differs depending on the type of the film holder 17. In the present embodiment, since the pixel data of the film area is appropriately extracted and used in S33 and the like to be described later, it is necessary to set a boundary luminance value between the film holder area and the film area in advance.

Then, in S32, a threshold Threshold, which is a boundary luminance value between the film holder area and the film area, is set based on the luminance histogram. Specifically, first, as shown in FIG. 6, a search is made for a brightness value having a maximum frequency in a search range having a low brightness value, and the brightness value is determined as a determination value m_Threshold.
Is defined. Next, as shown in Table 1 below, the discrimination value m_Thre
If shold is less than a predetermined luminance value α (hereinafter, referred to as a reference value α) in the search range, the sum of the discrimination value m_Threshold and a predetermined first addition value β is set as the threshold Threshold. On the other hand, if the discrimination value m_Threshold is equal to or more than the reference value α, the sum of the discrimination value m_Threshold and the second addition value γ larger than the first addition value β is set as the threshold Threshold. Setting the threshold Threshold in this way is based on the discrimination value m
When _Threshold is smaller than the reference value α, the discrimination value m_Thre
This is because the film holder area converges to a narrow range centered on shold, while when the discrimination value m_Threshold is equal to or larger than the reference value α, the film holder area spreads over a relatively wide range. The reference value α, the first addition value β, and the second addition value γ can be set empirically by analyzing a luminance histogram obtained using various film holders 17, and in this embodiment, α = 15, β =
20, γ = 35.

[0046]

[Table 1]

Subsequently, in step S33, RGB values are extracted from the image data in the storage unit 162 for the pixels in the range from the threshold value Threshold to the predetermined upper limit value Max in the luminance histogram, and a histogram of the RGB values as frequency distribution data is extracted. Generate Here, the upper limit value Max corresponds to the boundary luminance value between the film area and the background area in the luminance histogram, and is set to 225 in this embodiment.

After the frequency distribution data is generated as described above, it is determined whether or not a film is mounted on the film holder 17 in the following S13. Specifically, first, the cumulative frequency F in the range from the threshold Threshold to the upper limit Max is calculated for the luminance histogram by the following (Equation 1). In the following (Equation 1), ylist [i] is the frequency of the class value i in the luminance histogram.

[0049]

(Equation 1)

In S13, if the cumulative frequency F is smaller than the minimum film pixel number as shown in Table 2 below, it is determined that the film is not mounted on the film holder 17, and the cumulative frequency F is set to the minimum film pixel number. If so, it is determined that the film is mounted. Here, the minimum film pixel number is a value obtained by converting the minimum readable film size into the number of pixels by the resolution of image data.
For example, assuming that the minimum film size is 13.2 mm and the resolution of image data is 100 dpi, the minimum film pixel number can be calculated as the following (Equation 2).

[0051]

[Table 2]

[0052]

(Equation 2)

If it is determined in S13 that the film is mounted on the film holder 17, it is determined in next S14 whether the scan mode adopted in S11 is the negative mode or the positive mode.

Here, the case where it is determined in S14 that the scan mode is the negative mode will be described. In this case, a negative mode type determination routine is executed in S15 to determine the type of the film.

As shown in FIG. 7, in the negative mode type discriminating routine, first in S51, the first discriminating process is performed.
As shown in FIG. 8, a peak appears in a range where the B value is high in the B value histogram of the negative image data of the positive film. This is because when the positive film is scanned in the negative mode, the exposure amount of the B channel becomes excessive due to the setting of the charge accumulation time of the linear sensor 20 described above. Therefore, in S51, first, as a numerical value indicating the bias of the distribution of the B-value histogram, the ratio Brate of the cumulative frequency of the range in which the B value is high (250 to 255 in this embodiment) to the total number of pixels in the B-value histogram is expressed by Calculated by 3).
In the following (Equation 3), blist [i] is the frequency of the class value i in the B-value histogram. Next, when the rate Brate is equal to or more than the predetermined reference value δ, the film is determined to be a positive film, and when the rate Brate is less than the reference value δ, the next determination processing is performed in S52. The reference value δ can be set empirically by analyzing negative image data of a positive film, and is set to 0.015 in this embodiment. As described above, in S51, the positive film is determined using the B value histogram, but may be determined using the G value histogram. Further, a median value, a mode value, an average value, or the like may be adopted as a numerical value representing the bias of the histogram in S51.

[0056]

(Equation 3)

As shown in FIG. 9A, the distribution of the R-value histogram is biased toward the side having a larger class value than that of the B-value histogram for the negative data of the color negative film. On the other hand, as for the negative image data of the monochrome negative film, as shown in FIG. 9B, the distribution of the B-value histogram is biased toward the side where the class value is larger than the distribution of the R-value histogram. In S52, based on such knowledge, first R
Median values (median) Rmed and Bmed for each of the R value and B value histograms are calculated as numerical values representing the relative distribution bias between the value histogram and the B value histogram. Subsequently, the median Rmed and Bmed are compared, and the median Rmed
Is greater than or equal to the median value Bmed, it is determined that the film is a color negative film. If the median value Rmed is less than the median value Bmed, the film is determined to be a monochrome negative film. In S52, a mode value, an average value, or the like may be adopted as a numerical value representing the deviation of the distribution relative to the histogram. In S52, it is possible to determine whether the film is a color negative film or a monochrome negative film by comparing the G value histogram with the R value histogram instead of the B value histogram to check the relative distribution bias. .

The case where the scan mode is determined to be the negative mode in S14 has been described above. Next, S1
The case where the scan mode is determined to be the positive mode in 4 will be described. In this case, the type of the film is determined by executing a positive mode type determination routine in S16.

As shown in FIG. 10, in the positive mode type determination routine, first, a first determination process is performed in S71. As shown in FIG. 11A, generally, each value histogram of positive image data of a positive film has a high correlation with each other. On the other hand, the positive image data of the color negative film and the monochrome negative film are shown in FIG.
As shown in (d), the correlation between the R value histogram and the B value histogram is low. In S71, based on these findings, first, a cross-correlation coefficient dbr indicating the degree of correlation between the R value histogram and the B value histogram is calculated according to the following (Equation 4). In the following (Equation 4), rlist [i] and blis
t [i] is the frequency of the class value i in the R value and B value histograms, respectively. Further, mr and mb are average values of the class value i in the R value and B value histograms, respectively, and can be calculated by the following (Equation 5). In S71, when the cross-correlation coefficient dbr is larger than the predetermined reference value ε, the film is determined to be a positive film,
If the cross-correlation coefficient dbr is equal to or smaller than the reference value ε, S72
Performs the second determination process. The reference value ε can be set empirically by analyzing positive image data of a positive film,
In this embodiment, it is set to 0.75.

[0060]

(Equation 4)

(Equation 5)

In S71, all the positive films cannot be determined. This is because, as shown in FIG. 11B, the correlation of each value histogram of positive image data is lower in a positive film on which an image close to a single color is recorded than in a positive film which does not. By the way, as shown in FIGS. 11B and 11C, in the case of positive image data of a positive film on which an image close to a single color is recorded, the R value for the distribution of the B value histogram is larger than that of the positive image data of a color negative film. The bias of the histogram distribution is small. Therefore, in S72, first, as a numerical value representing the bias of the relative distribution between the R value histogram and the B value histogram, R
The average value mr and mb of the class value i in the value and B value histograms are calculated by the above (Equation 5). Next, the average value mr and
If the ratio mr / mb with respect to mb is less than a predetermined first reference value ζ, the film is determined to be a positive film, and if the ratio mr / mb is greater than a predetermined second reference value η, the film is determined to be positive. If it is determined that the film is a color negative film, and the ratio mr / mb is equal to or more than the first reference value か つ and equal to or less than the second reference value η, S7
At 3, the third determination process is performed. The first reference value ζ and the second reference value η can be set empirically by analyzing positive image data of a positive film and a color negative film, respectively. In this embodiment, ζ = 1.3, η = 1.6. Is set to In step S72, an average value, a cumulative frequency, a median value, a mode value, or the like may be used as a numerical value representing the deviation of the distribution relative to the histogram.

According to S71 and S72, a positive film and a color negative film can be distinguished, but a monochrome negative film cannot be distinguished. By the way, FIG.
As shown in (c) and (d), in the color negative film and the monochrome negative film, due to the characteristics of the film, the distribution of the R value histogram for the positive image data is remarkably higher than the distribution of the B value histogram on the side of the larger class value. Biased.
In the color negative film and the monochrome negative film, the former has a lower correlation between the G value histogram and the B value histogram for positive image data.

Based on the above findings, in S73, first, R
The relative distribution bias between the value histogram and the B-value histogram is expressed by comparing ranges in which the frequency is not 0 for these two histograms. Specifically, a range in which the frequency is not 0 for each of the R value and the B value histograms is specified as a numerical value indicating the relative distribution bias, and a class value at the center of the range (hereinafter, simply referred to as a central class value). ) Calculate rr and rb. For example, when the class whose frequency is not 0 in the R value histogram is 20 or more and 200 or less, rr = (20 + 200) / 2 = 110.
Second, the cross-correlation coefficient dgb representing the degree of correlation between the G-value histogram and the B-value histogram is represented by the cross-correlation coefficient dbr of S71.
It is calculated in the same manner as described above. Next, the ratio of the center gradation value rr to rb
If rr / rb is equal to or less than a predetermined ratio reference value θ, it is determined that the film is a positive film, and the ratio rr / rb is compared with the ratio reference value θ.
If the value is larger and the cross-correlation coefficient dgb is less than the predetermined coefficient reference value ι, it is determined that the film is a color negative film, and the ratio rr / rb is larger than the ratio reference value θ and If the number dgb is equal to or more than the coefficient reference value ι, it is determined that the film is a monochrome negative film.
The ratio reference value θ and the coefficient reference value ι can be set empirically by analyzing positive image data of various films. In this embodiment, θ = 1.15, ι = 0.7 I have. In step S73, an average value, a cumulative frequency, a median value, a mode value, or the like may be employed as a numerical value representing the deviation of the distribution relative to the histogram.

After the type of film is determined in S15 or S16 as described above, in S17, a screen for instructing the user to input a document reading start command is displayed on the monitor 154. It waits until a document reading start command is input.

When the user inputs a document reading start command, in step S18, the light source 38 for the transparent document is turned on at a luminance suitable for the determined film type, and the carriage 24 is moved in the scan mode corresponding to the film type. The transmitted light image of the film is scanned by the linear sensor 20. Then, the output signal of the linear sensor 20 is processed by the processing unit 110 to generate image data, and the generated image data is transferred to the PC 150. In this embodiment, the reading resolution of the transmitted light image in S18 is set to the resolution input by the user together with the document reading start command, for example, 800 dpi, 1600 dpi, or the like higher than that in S11. As described above, the PC 150 acquires the image data representing the density of the original image recorded on the film.

As described above, when the CPU 160 of the PC 150 executes the film control program, the histogram of each of the RGB values generated based on the negative data or the positive image data shows a unique frequency distribution for each film type. The reading system 10 can automatically and accurately determine the type of the film by paying attention to such a difference in the distribution of each value histogram. In addition, since the image reading system 10 determines the type of the film and then performs the film reading processing according to the type, the desired film can be read properly.

As is clear from the above description, in this embodiment, the linear sensor 20, the light source 38 for the transparent original, the mirror 3
4, the condenser lens 36, the drive unit 40, and the processing unit 110 constitute an example of the “imaging unit” described in the claims.

In this embodiment, the CPU 160 and the C
The PU 130 constitutes an example of the “first processing means” and an example of the “third processing means” according to claim 1 and claim 4,
The PU 160 constitutes an example of the “second processing means” according to claim 1 and claim 4, and the part of the CPU 160 that performs the processing of S <b> 51 is the “second processing means” according to claim 2.
The part of the CPU 160 that performs the processing of S52 forms an example of the “second processing unit” according to claim 3, and the part of the CPU 160 that performs the processing of S71 is defined by claim 5. A part of the CPU 160 that performs the processing of S72 constitutes an example of the “second processing means” described in claim 6,
The part of the PU 160 that performs the processing of S73 constitutes an example of the “second processing means” according to claim 7.

Further, in this embodiment, the CPU 160
S11 constitutes an example of the “first scanning control procedure” according to claims 8 and 11, among the processing steps performed by
12 constitutes an example of the “first processing procedure” described in claims 8 and 11, S15 constitutes an example of the “second processing procedure” described in claim 8, and S16 describes in claim 11 An example of the “second processing procedure” described above is configured, and S18 is an example.
S51 constitutes an example of the "second scanning control procedure" according to claim 11, S51 constitutes an example of the "second processing procedure" according to claim 9, and S52 forms the "second scanning control procedure" according to claim 10. S71 constitutes an example of the "second processing procedure", and S72 constitutes an example of the "second processing procedure".
And S73 constitutes an example of the “second processing procedure” according to claim 14.

Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention is not construed as being limited by the description of the embodiment.

For example, in the above embodiment, the image reading system 10 is different from the image scanner 11 and the PC
150. On the other hand, the image reading system described in the claims may be configured to integrally include an image reading unit such as a scanner and an image processing unit such as a computer.

[Brief description of the drawings]

FIG. 1 is a flowchart showing each processing step executed by a personal computer (PC) of an image reading system according to an embodiment of the present invention executing a film control program.

FIG. 2 is a block diagram illustrating an image reading system according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view schematically illustrating an image reading system according to an embodiment of the present invention.

FIG. 4 is a plan view showing a film holder used in the image scanner of FIG. 3;

FIG. 5 is a flowchart showing each processing step of a frequency distribution data generation routine executed in S12 of FIG. 1;

FIG. 6 is a graph showing an example of a luminance histogram obtained in S31 of FIG.

FIG. 7 is a flowchart showing each processing step of a negative mode type determination routine executed in S15 of FIG. 1;

FIG. 8 is a graph showing a B value of negative image data obtained by scanning a positive film in a negative mode by the image scanner of FIG. 3;
It is a graph which shows a value histogram.

9 shows the R value and B for negative image data obtained by scanning a color negative film (a) or a monochrome negative film (b) in a negative mode by the image scanner of FIG. 3;
It is a graph which each shows a value histogram.

FIG. 10 is a flowchart showing each processing step of a positive mode type determination routine executed in S16 of FIG. 1;

11 is a graph showing RGB value histograms for positive image data obtained by scanning various films in the positive mode by the image scanner of FIG. 3, wherein (a) to (d) are general positive images, respectively. 3 shows the case of a film (a), a positive film (b) close to a single color, a color negative film (c), and a monochrome negative film (d).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Image reading system 11 Image scanner 17 Film holder 20 Image sensor (linear sensor) 26 Sub-scanning drive unit 30 Optical system 37 Transmission original unit 38 Light source for transmission original 40 Drive unit 100 Processing unit 102 Main scanning drive unit 110 Control unit 130 CPU 150 Personal computer (PC) 160 CPU 162 Storage unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/04 H04N 1/04 D 5C079 1/60 1/40 D (72) Inventor Tetsuya Mizuno Suwa, Nagano 3-5-5 Yamato-shi, Seiko Epson Corporation (72) Inventor, Yasuo Asagi 1077, Ogata Shimonosato, Ueda-shi, Nagano Prefecture Epson Kowa Co., Ltd. No. 5 Epson Kowa Co., Ltd. (72) Inventor Hiroyuki Kawajiri 1077-5, Shimonosato Oto, Oda, Ueda-shi, Nagano Epson Kowa Co., Ltd. F term (reference) 5B047 AA05 AB04 BB02 5B057 AA20 BA02 BA26 BA30 DA12 DB02 DB06 DB09 DC19 5C062 AB03 AB17 AB40 AC02 5C072 AA01 BA19 EA05 VA03 5C077 MM03 MP08 PP32 PQ12 PQ18 PQ19 PQ20 PQ22 5C079 HB01 JA01 JA23 LA02 LA03 MA01 MA11 NA18

Claims (15)

[Claims] 1. A negative image data representing characteristic values of three colors weighted independently for each color of a transmitted light image of a film by color-scanning a transmitted light image of the film by photoelectric conversion, or independently for each color of the transmitted light image. Imaging means for outputting positive image data representing characteristic values of the three colors which are not weighted; and frequency distribution data representing the frequency distribution of the characteristic values based on the output of the negative image data to the imaging means. A first processing unit that outputs the negative image data or the positive image data to the imaging unit according to the type of the film. An image reading system comprising: three processing means. 2. The method according to claim 1, wherein the second processing unit determines that the film is a positive film in accordance with a degree of deviation of a frequency distribution of characteristic values of weighted colors of the transmitted light image. 2. The image reading system according to 1. 3. The three independent colors are R (red), G
(Green) and B (blue), wherein the second processing means is configured such that when the frequency distribution of the characteristic value of R is biased to a value larger than the frequency distribution of the characteristic value of B in the transmitted light image, 2. The film according to claim 1, wherein the film is determined to be a color negative film, and the film is determined to be a monochrome negative film when the frequency distribution of the characteristic value of B is biased to a value larger than the frequency distribution of the characteristic value of R. Or the image reading system according to 2. 4. An R image weighted for each color of the transmitted light image by scanning the transmitted light image of the film by photoelectric conversion.
Negative data representing characteristic values of (red), G (green) and B (blue) or R not weighted for each color of the transmitted light image,
Imaging means for outputting positive image data representing the characteristic values of G and B; and a frequency distribution representing the frequency distribution of the characteristic values of R, G and B based on the output of the positive image data to the imaging means. First processing means for outputting data; second processing means for determining the type of the film based on the frequency distribution data; and outputting the negative data or the positive image data to the imaging means according to the type of the film. An image reading system comprising: a third processing unit. 5. The second processing means determines that the film is a positive film according to a degree of correlation between a frequency distribution of characteristic values of B and a frequency distribution of characteristic values of R for the transmitted light image. 5. The image reading system according to claim 4, wherein: 6. The second processing means, wherein the film is a positive film or a color negative film according to the degree of deviation of the frequency distribution of R characteristic values with respect to the frequency distribution of B characteristic values for the transmitted light image. The image reading system according to claim 5, wherein the determination is made as follows. 7. The second processing means, wherein the film is a positive film or a negative film according to the degree of deviation of the frequency distribution of R characteristic values with respect to the frequency distribution of B characteristic values for the transmitted light image. When the film is determined to be a negative film, the negative film is further converted into a color negative film according to the degree of correlation between the frequency distribution of the characteristic values of G and the frequency distribution of the characteristic values of B for the transmitted light image. 7. The image reading system according to claim 6, wherein the image is determined to be a monochrome negative film. 8. A computer for controlling an imaging unit of an image reading system that scans an optical image by photoelectric conversion. The imaging unit performs a color scan of a transmitted light image of a film, and weights the transmitted light images independently of each other for each color. A first scanning control procedure for outputting the negative image data representing the characteristic values of the three colors, and a first processing for outputting frequency distribution data representing the frequency distribution of the characteristic values of the three colors based on the negative image data output by the imaging means. A procedure, a second processing procedure for determining the type of the film based on the frequency distribution data, and color-scan the transmitted light image of the film to the imaging means according to the type of the film, the negative image data or the transmitted light image A second scanning control procedure for outputting positive image data representing characteristic values of three colors independent of each other and not weighted for each color, and Image reading system control program that. 9. The film processing apparatus according to claim 2, wherein in the second processing procedure, the film is determined to be a positive film according to a degree of deviation of a frequency distribution of characteristic values of weighted colors of the transmitted light image. 8. A control program for the image reading system according to 8. 10. The three independent colors are R (red), G
(Green) and B (blue). In the second processing procedure, when the frequency distribution of the characteristic value of R in the transmitted light image is biased to a value larger than the frequency distribution of the characteristic value of B, 9. The film according to claim 8, wherein the film is determined to be a color negative film, and the film is determined to be a monochrome negative film when the frequency distribution of the characteristic value of B is biased to a value larger than the frequency distribution of the characteristic value of R. Or a control program for the image reading system according to 9. 11. A computer for controlling an imaging unit of an image reading system that scans an optical image by photoelectric conversion, wherein the imaging unit performs color scanning of a transmitted light image of a film and does not weight each color of the transmitted light image. R (red), G
A first scanning control procedure for outputting positive image data representing characteristic values of (green) and B (blue); and a frequency distribution representing a frequency distribution of characteristic values of R, G, and B based on the positive data output by the imaging means. A first processing procedure for outputting data, a second processing procedure for determining the type of the film based on the frequency distribution data, and performing color scanning of the transmitted light image of the film by the imaging unit according to the type of the film. A second scanning control procedure for outputting positive image data or negative image data representing R, G, and B characteristic values weighted for each color of the transmitted light image, and a control program for an image reading system. 12. In the second processing procedure, the film is determined to be a positive film according to a degree of correlation between a frequency distribution of characteristic values of B and a frequency distribution of characteristic values of R for the transmitted light image. The control program for an image reading system according to claim 11, wherein: 13. In the second processing procedure, the film is a positive film or a color negative film according to the degree of deviation of the frequency distribution of R characteristic values with respect to the frequency distribution of B characteristic values for the transmitted light image. 13. The control program for an image reading system according to claim 12, wherein: 14. In the second processing procedure, the film is a positive film or a negative film according to the degree of deviation of the frequency distribution of R characteristic values with respect to the frequency distribution of B characteristic values for the transmitted light image. When the film is determined to be a negative film, the negative film is further converted into a color negative film according to the degree of correlation between the frequency distribution of the characteristic values of G and the frequency distribution of the characteristic values of B for the transmitted light image. 14. The control program according to claim 13, wherein the program is determined to be a monochrome negative film. 15. A computer-readable recording medium storing a control program for the image reading system according to claim 8. Description: