JP3294249B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for converting an input image having a certain resolution into a plurality of output images having different resolutions in which pattern edges are smoothed.

[0002]

2. Description of the Related Art As this kind of prior art, for example, an image processing apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 5-17767 is known. This conventional apparatus uses, for example, a laser beam printer to set the output image resolution to 300 dpi (dots / inch) and 6 dpi.
00 dpi, two interpolation logic circuits connected between the printer controller and the printer engine. One of the two interpolation logic circuits is selected by a signal for selecting the resolution of the printer engine. It is selectively activated. And
One of the two interpolation logic circuits receives a 300 × 300 dpi image from the printer controller and smoothes the edges of the pattern of the input image to 1200 × 300 dpi.
It has a function of converting to an output image of 300 dpi. Also, the other interpolation logic circuit doubles the resolution of the input image and smoothes the pattern edge to 1200
It has a function of converting to an output image of × 600 dpi.

[0003]

One problem of this conventional device is that the number of interpolation logic circuits corresponding to the number of selectable resolutions is required, so that the amount of hardware increases and the cost increases. It is.

Accordingly, it is an object of the present invention to provide an image processing apparatus for converting an input image having a certain resolution into an output image having a plurality of different resolutions. By doing
The object is to reduce the total hardware amount.

[0005]

Means for Solving the Problems The present invention is an image processing apparatus for converting an input image of a resolution smoothed output images, receives an input image, a first output resolution that is smoothed Correction amount calculating means for calculating a first edge correction amount to be applied to an input image in order to obtain an output image, and an output image having a second output resolution subjected to smoothing processing in response to the first edge correction amount Resolution conversion means for converting the input image into a second edge correction amount to be applied to the input image, and selectively inputting one of the first edge correction amount and the second edge correction amount to obtain the input edge correction Output image creating means for creating an output image having a corresponding resolution by performing a process for applying the amount to the input image.

[0006]

The image processing apparatus of the present invention can selectively output at least two types of output images of the first output resolution and the second output resolution. This device includes three components: a correction amount calculation unit, a resolution conversion unit, and an output image creation unit.

The correction amount calculating means performs a smoothing process for converting an input image into an output image having a first output resolution, and performs a first process for smoothing an edge of a pattern of the input image. Is calculated.

On the other hand, the resolution conversion means receives the first edge correction amount and converts it into a second edge correction amount for obtaining an output image of the second output resolution.

Either the first edge correction amount or the second edge correction amount is selectively input to the output image creating means. The output image creating means performs a process for applying the input edge correction amount to the input image. Therefore, when the first edge correction amount is input, an output image with the first output resolution is created, and when the second edge correction amount is input,
An output image of the second output resolution is created.

In this apparatus, the correction amount calculating means and the output image creating means are commonly used through the first and second output resolutions. Only the resolution conversion means is dedicated to the second output resolution. Therefore, an increase in the amount of hardware due to an increase in the selectable resolutions is only for the resolution conversion means, so that the total amount of hardware can be reduced as compared with the prior art.

The preferred embodiment has an output resolution of 300
Although dpi and 600 dpi can be selected, the ratio of the resolution converter corresponding to the resolution converter to the entire apparatus is very small. Therefore, the hardware amount of the device of this embodiment is not much different from the hardware amount of the conventional device which outputs only 300 dpi.

[0012]

FIG. 1 shows a hardware configuration of an embodiment of a control device of a laser printer to which the present invention is applied.

The control device 1 receives print data from an external device 3 such as a personal computer, creates bitmap data of an output image based on the print data, and converts the bitmap data into actual image formation. This is output to the laser beam modulation circuit 5 for performing the operation.
Here, the resolution of the laser beam modulation circuit 5 (hereinafter referred to as output resolution) can be selected, for example, between two types of 300 dpi and 600 dpi, and a bit generated by the control device 1 in accordance with the selected output resolution. The resolution of the map data is also changed. One feature of the present invention is embodied in a configuration for changing the resolution of the bitmap data, specifically, a bitmap data generation circuit 27 described later.

The control device 1 includes a central processing unit (CPU) 11 for processing print data, a RAM 13 used as a main memory, a work area, a reception buffer, and the like.
A ROM 15 storing an operation program of the PU 11, a character generator 17 containing font data for converting a character code in the print data into bitmap data of characters, and a page-based image generated based on the print data. A page frame buffer 19 for storing bitmap data is provided. C
The PU 11 operates in synchronization with the clock signal from the clock signal generation circuit 21.

The print data received from the external device 3 is
The data is taken into the bus 25 via the interface circuit 23, processed by the CPU 11, converted into basic bitmap data for modulating the laser beam, and stored in the page frame buffer 19. The resolution of this basic bitmap data is 300 dpi × horizontal.
The vertical direction is 300 dpi.

In the following description, the resolution is set to, for example, "12".
00 dpi × 300 dpi ”, where the number before“ x ”indicates the resolution in the horizontal direction and the number after it indicates the resolution in the vertical direction.

The basic bitmap data of 300 dpi × 300 dpi is read into the bitmap data generating circuit 27, and is subjected to a process for smoothing the edge of the pattern (hereinafter, referred to as a smoothing process). Is converted to bitmap data. This final bitmap data is created at a resolution corresponding to the selected output resolution, as described above.
That is, when the output resolution is 300 dpi, the resolution of the final bitmap data is 1200 dpi × 300.
If the resolution is 600 dpi and the output resolution is 600 dpi, it is 1200 dpi × 600 dpi. Here, the reason why the horizontal resolution becomes 1200 dpi is a result of performing the smoothing process. That is, in the smoothing process, a dot having a width equivalent to one quarter of one pixel of the basic bitmap data is added or deleted to the step-shaped portion of the edge of the pattern, so that the edge is smoothly formed without a step. It is modified so that it can be seen.

The final bitmap data is output to the laser beam modulator 5 to perform on / off modulation of the laser beam. Further, the CPU 11 controls the driving of the photosensitive drum 7 via the bit shift circuit 29 and the address circuit 31 to control the rotation of the photosensitive drum 1 so as to be suitable for writing bitmap data. As a result, the laser beam draws an electrostatic latent image corresponding to the final bitmap data on the surface of the photosensitive drum 7.

The CPU 11 further includes an I / O control circuit 33
And various kinds of control signals to the bitmap data generation circuit 27. The laser beam modulation circuit 5 also sends necessary control signals to the bitmap data generation circuit 27. The control signals include, for example, a video clock signal synchronized with the on / off modulation cycle of the laser beam, a horizontal synchronization signal synchronized with the cycle of the horizontal scanning of the laser beam, and a resolution selection signal for selecting an output resolution. and so on.

Of the above configuration, a bitmap data generation circuit 27 embodying one feature of the present invention.
Will be described in detail below.

FIG. 2 shows a bit map data generation circuit 27.
2 shows the internal configuration of FIG.

In FIG. 2, basic bitmap data of 300 dpi.times.300 dpi is supplied from a page frame buffer 19 (not shown), starting from the leftmost pixel of the top horizontal line of the page, and moving down each horizontal line from left to right. The data is read out at a fixed timing by the raster scan method in the order from the upper horizontal line to the lower horizontal line. The read pixel data of one horizontal line is written to the RAM 43 through the latch 41.

The RAM 43 has nine FIFOs each having a capacity to hold bit map data for one horizontal line.
This is equivalent to a configuration in which O memories are arranged in parallel, and data of one horizontal line from the latch 41 described above is written to the first FIFO memory. Data of eight horizontal lines from eight latches 45 to 59 described later are stored in RAM.
43 are written to the second to ninth FIFO memories, respectively. Therefore, the RAM 43 stores bitmap data for nine consecutive horizontal lines.

From the RAM 43, the stored 9
The data of the nine pixels located at the same horizontal position that is read first in the horizontal line of the book is read out in synchronization. Pixel data at the same position on these nine horizontal lines is 9
The data are input to nine nine-stage shift registers 63 to 79 through the latches 45 to 61, respectively. The shift registers 63 to 79 sequentially shift the input pixel data of the horizontal line to the subsequent stages. Therefore, the shift registers 63 to 79 hold bitmap data of an area of 9 pixels × 9 pixels.
The nine-pixel area is shifted in the horizontal direction one pixel at a time at a fixed timing. When the horizontal shift reaches the end of the horizontal line, the area is shifted vertically by one horizontal line, and the same horizontal shift is repeated again. In other words, 300 dpi × 300 dpi stored in the page frame buffer
One page of the basic bitmap data of i is scanned in the horizontal and vertical directions by windows of 9 × 9 pixels created by the shift registers 63 to 79 (hereinafter, the above window is scanned). Window).

In this scanning window, 9 pixels ×
The 9-pixel bitmap data is supplied to the horizontal line edge calculation unit 81.
And the vertical line edge calculation unit 83. The horizontal line edge calculation unit 81 calculates the vertical differentiation (= black and white change) of the input 9 pixel × 9 pixel bitmap data, thereby obtaining the horizontal line (= horizontal component) of the black pattern existing in the scanning window. ) Is detected. That is, the black pixel at the position where the differential in the vertical direction has risen (= changed from white to black) is defined as the rising edge (= upper edge) of the horizontal line, and the position of the fall (= changed from black to white). Are detected as falling edges (= lower edges) of horizontal lines.

On the other hand, the vertical line edge calculating section 83 calculates the horizontal differentiation of the input 9-pixel × 9-pixel bitmap data, thereby obtaining the vertical lines (= vertical lines) of the black pattern existing in the scanning window. (Direction component). That is, the black pixel at the position where the differential in the horizontal direction has risen is defined as the rising edge of the vertical line (=
A black pixel at a falling position is detected as a falling edge (= right edge) of a vertical line.

The data indicating the rising edge and the falling edge of the horizontal line and the vertical line detected by the horizontal line edge calculating section 81 and the vertical line edge calculating section 83 are obtained by a horizontal line edge feature extracting calculating section 85 and a vertical line edge calculating section 87. Are input respectively.

The horizontal line edge feature calculation unit 85 determines the relative positions of the detected rising edge and falling edge of the horizontal line with respect to the pixel DX (hereinafter, referred to as a target pixel) located at the center of the scanning window. Focusing on whether there is, the rising edge and the falling edge are classified. That is, with respect to the rising edge (= upper edge), first, out of all the rising edges, a predetermined positional relationship (for example, a significant upper edge) with respect to the pixel of interest DX (for example,
Only the edges within the mask area shown in FIG. 3) are extracted,
The pixel constituting the extracted upper edge is the pixel of interest DX.
Data AU, BU, CU, DU, FU, GU characterizing the shape of the upper edge from the viewpoint of what pixel is located above or below and at what pixel is located leftward or rightward
Is calculated. Also, falling edge (= lower edge)
, First, only those edges that are substantially in a predetermined positional relationship (for example, in the mask area shown in FIG. 4) having a meaning of the lower edge with respect to the pixel of interest DX are extracted, and the extracted lower edge is extracted. Data AD, BD, CD, and CD that characterize the shape of the lower edge from the viewpoint of how many pixels the constituent pixels are located above or below the target pixel DX and at what position to the left or right. Calculate DD, FD, GD.

Here, the shape characteristic data A of the upper edge
The meanings of the shape feature data AD, BD, CD, DD, FD, and GD of U, BU, CU, DU, FU, and GU and the lower edge will be supplementarily described as follows. That is, FIG.
As shown in FIG. 4 and FIG.
A, B, depending on the number of pixels (distance) in the left-right direction from
It is divided into C, D, F, and G pixel columns. Then, with respect to the upper edge, pixel columns A,
Each of the data AU, BU, CU, DU, FU, and GU (4-bit data) is formed according to a predetermined logical expression for extracting the shape feature of the upper edge in accordance with each of the monochrome patterns B, C, D, F, and G. I can decide. Also, for the lower edge,
Data AD, BD, CD, D according to a predetermined logical expression for extracting a lower edge shape characteristic according to each black-and-white pattern of pixel rows A, B, C, D, F, and G in the mask area of FIG.
Each of D, FD, and GD (4-bit data) is determined.

On the other hand, the vertical line edge feature calculator 87 pays attention to the relative positions of the detected rising edge and falling edge of the vertical line with respect to the target pixel DX, respectively. The rising edge and the falling edge are classified. That is, with respect to the rising edge (= left edge), first, from among all the rising edges, a predetermined positional relationship having substantially the meaning of the left edge with respect to the pixel of interest DX (for example, in the mask area shown in FIG. 5). ) Is extracted, and from the viewpoint of the number of pixels above or below the pixel of interest DX and the number of pixels to the left or right of the pixel constituting the extracted left edge, Data AL, BL, CL, DL and EL characterizing the shape of the edge are calculated. As for the falling edge (= right edge), first, only the edge having a predetermined positional relationship (for example, in the mask area shown in FIG. 5) having the significance of the right edge with respect to the pixel of interest DX is extracted. The data AR characterizing the shape of the right edge from the viewpoint of the number of pixels above or below the pixel constituting the extracted right edge and the number of pixels to the left or right of the pixel of interest. , B
Calculate R, CR, DR, ER.

Here, the shape characteristic data A of the left edge
The meanings of L, BL, CL, DL, EL and the right-side edge shape feature data AR, BR, CR, DR, ER will be supplementarily described as follows. That is, as shown in FIG. 5, the inside of the mask area is divided into A, B, C, D, and E pixel rows according to the number of pixels (distance) in the vertical direction from the target pixel DX. As for the left edge, FIG.
Data AL, BL, CL, DL, and EL according to a predetermined logical expression for extracting the shape feature of the left edge in accordance with the black and white pattern of each of pixel rows A, B, C, D, and E in the mask region of FIG.
(AL and CL are 4-bit data, BL and DL are 6
Bit data and EL are 2-bit data).
Also, for the right edge, the data AR, BR according to a predetermined logical expression for extracting the shape characteristic of the right edge in accordance with each black and white pattern of the pixel rows A, B, C, D, and E in the mask area of FIG. , CR, DR, ER (AR and C
R is 4-bit data, BR and DR are 6-bit data, E
R is 2-bit data).

The data characterizing the shapes of the rising edge and the falling edge of the horizontal and vertical lines calculated by the edge feature extraction calculation units 85 and 87 are respectively an upper edge correction amount calculation unit 89 and a lower edge correction amount calculation. The input is input to the section 91, the left edge correction amount calculation section 93, and the right edge correction amount calculation section 95.

The upper edge correction amount calculator 89 calculates the characteristic data AU, BU, CU, DU, FU,
Based on the GU, a dot addition amount and a shaving amount for smoothing processing on the upper edge are calculated. In addition, the lower edge correction amount calculation unit 91 calculates the addition amount of the dot for smoothing processing on the lower edge based on the characteristic data AD, BD, CD, DD, FD, and GD of the lower edge of the horizontal line. Calculate the shaving amount. FIG. 6 shows an example of the calculation result of the dot addition amount and the shaving amount with respect to this horizontal line. When an original horizontal line pattern as shown in the upper part of the figure is given, the upper edge and the lower edge of this original pattern are given. A dot of 1/4 size of one pixel (hereinafter, referred to as a 1/4 dot) is added to a step portion of the side edge,
For example, it is corrected so that the stepped portion looks smooth by being deleted.

On the other hand, the left edge correction amount calculating section 93 calculates the characteristic data AL, BL, CL, DL,
Based on the EL, a dot correction amount for smoothing processing on the left edge is calculated. Further, the right edge correction amount calculation unit 95 calculates a dot correction amount for smoothing processing on the right edge of the vertical line based on the characteristic data AR, BR, CR, DR, ER of the right edge. FIG. 7 shows an example of a calculation result of the correction amount for the vertical line. When an original vertical line pattern as shown in the left part of the figure is given, the positions of the pixels constituting the original pattern are determined. The left edge and the right edge are corrected so as to shift right and left in units of 1/4 dot, so that the steps of the original pattern are corrected so that they look smooth.

As can be seen from FIGS. 6 and 7, the correction amounts for the horizontal and vertical line edges calculated as described above are obtained by converting the basic bitmap data of 300 dpi × 300 dpi to the final 1200 dpi × 300 dpi. This is the amount of correction for conversion to typical bitmap data, that is, the amount of correction for smoothing processing when the output resolution is 300 dpi.

The above-described edge calculation units 81 and 83 for calculating the correction amount for the output resolution of 300 dpi are used.
Edge feature extraction calculation units 85 and 87 and correction amount calculation unit 89
-95, refer to JP-A-5-649.
No. 23 (in particular, FIG.
See description corresponding to). This publication describes the processing by software, but the processing content is NOT
And a simple logical operation combining AND, and in the present embodiment, this is realized by a hard logic circuit.

The correction amount for the vertical line among the correction amounts for the output resolution of 300 dpi calculated by the above configuration is directly input to the output determination calculation unit 103. on the other hand,
The addition amount and the shaving amount related to the horizontal line are input to a resolution conversion unit 97 described later on the one hand, and are input to the selector 101 together with the output data of the resolution conversion unit 97 on the other hand. here,
The resolution converter 97 outputs an output resolution of 300 d for the horizontal line.
The amount of addition and the amount of shaving for pi are converted to those for 600 dpi. Then, the selector 101 receives the resolution selection signal, sends the horizontal line correction amount for 300 dpi to the output determination calculation unit 103 when the output resolution of 300 dpi is selected, and outputs the horizontal line correction amount for 300 dpi when the output resolution of 600 dpi is selected. The horizontal line correction amount for the output resolution of 600 dpi from the resolution conversion unit 97 is determined by the output determination operation unit 10.
Send to 3.

The output determination calculation unit 103 creates final bitmap data subjected to smoothing processing based on the input horizontal line correction amount and vertical line correction amount. The specific processing contents of the output determination operation unit 103 are also described in
-64923.

One of the new constructions in this embodiment is that the output of the above-described output resolution of 300 dp
The point is that the horizontal line correction amount for i is converted to a correction amount for an output resolution of 600 dpi.

FIG. 8 shows an example of the conversion. Assuming that a correction amount for a horizontal line for an output resolution of 300 dpi as shown in the upper part of FIG. 8 is given, this is converted into a correction amount for an output resolution of 600 dpi as shown in the lower part of FIG. The law of this conversion is as follows. That is,
As shown in FIG. 8, one horizontal line at 300 dpi is divided into two upper and lower horizontal lines at 600 dpi. The 1/4 dot added at 300 dpi is invalid (= not added) in the upper line of the upper edge at 600 dpi, valid (= added) in the lower line of the upper edge, and in the upper line of the lower edge in 600 dpi. Effectiveness,
And is invalid on the lower line of the lower edge. Also, 3
The 1/4 dot deleted at 00 dpi is 600 dpi
Is valid (= deleted) in the upper line of the upper edge, invalid (= not deleted) in the lower line of the upper edge, invalid in the upper line of the lower edge, and valid in the lower line of the lower edge. .

The resolution conversion unit 97 calculates the amount of addition and deletion of the horizontal line for the output resolution of 600 dpi according to this rule. The basic logic is shown below.

ADD = addU · LIN2 + addD · LIN1 (1) DEL = delU · LIN1 + delD · LIN2 (2) PIC = pic + delU · LIN2 + delD · LIN1 (3) where ADD, DEL and PIC are , 600 dpi, １ ／ dot addition, １ ／ dot removal, and one-pixel complete printing, respectively. Also, addU, addD, d
elU, delD and pic are 1/4 dot addition of the upper edge, 1/4 dot addition of the lower edge, 1/4 dot shaving of the upper edge, and 1/1 of the lower edge at 300 dpi.
This means 4-dot shaving and 1-pixel complete printing, respectively.
Further, LIN1 and LIN2 are line signals that mean an upper line and a lower line at 600 dpi, respectively. These line signals LIN1 and LIN2 are 600d
It is generated by a 1-bit counter 99 that counts the horizontal synchronization signal at pi.

The logic of the above equation (1) indicates that the logic at 600 dpi is used only when adding 1/4 dots on the lower line of the upper edge at 300 dpi and when adding 1/4 dots on the upper line of the lower edge. This means that 1/4 dot addition is performed. Also, the logic of equation (2) indicates that 1/3 dot at 600 dpi is only used when deleting 1/4 dots in the upper line of the upper edge at 300 dpi and when deleting 1/4 dots in the lower line of the lower edge. This means that 4 dots are deleted. Further, the logic of the equation (3) is obtained by calculating 1/1 in the lower line of the upper edge when printing one pixel completely at 300 dpi.
1/4 of 4 dots deleted and upper line of lower edge
This means that one-pixel complete printing at 600 dpi is performed only at the time of dot deletion. According to this logic, the horizontal line correction amount for 300 dpi as shown in FIG.
Conversion to the horizontal line correction amount for 0 dpi is possible.

Note that 300 input to the resolution converter 97
The 1/4 dot addition amount and deletion amount data for dpi indicate not only information indicating whether to add or delete but also the position and the number of 1/4 dots to be added or deleted in the pixel. Information is also included. This position and number information is not taken into account in the basic logic described above,
This is also taken into account in the actual logical operation in the resolution converter 97. That is, for example, as in the example of FIG. 8, the number and positions of the added or deleted dots at 300 dpi are directly reflected in the pixels where the addition or deletion is effective even at 600 dpi.

As described above, the resolution conversion unit 97 calculates the output resolution 6 from the horizontal line correction amount for the output resolution 300 dpi.
By converting to the horizontal line correction amount for 00 dpi, it is possible to support the output resolution of 600 dpi by using the hardware resources for the output resolution of 300 dpi. Therefore, in a configuration in which a completely separate correction circuit is provided according to the conventional resolution. In comparison, the total hardware amount is greatly reduced.

[0046]

As described above, according to the present invention,
In an image processing apparatus for converting an input image having a certain resolution into output images having a plurality of different resolutions, the entire hardware amount can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a hardware configuration of an embodiment of a control circuit of a laser printer to which the present invention is applied.

FIG. 2 is a block diagram showing a detailed hardware configuration of a bitmap data generation circuit.

FIG. 3 is a diagram showing an example of a region mask used when extracting a feature of an upper edge of a horizontal line.

FIG. 4 is a diagram showing an example of a region mask used when extracting a feature of a lower edge of a horizontal line.

FIG. 5 is a diagram showing an example of a region mask used when extracting features of vertical line edges.

FIG. 6 is a diagram illustrating an example of horizontal line correction.

FIG. 7 is a diagram illustrating an example of vertical line correction.

FIG. 8 is a diagram illustrating an example in which a horizontal line correction amount for 300 dpi is converted into a horizontal line correction amount for 600 dpi.

[Explanation of symbols]

27 Bitmap Data Generation Circuits 41, 45, 47, 49, 51, 53, 55, 57, 5
9, 61 Latch 43 RAM 63, 65, 67, 69, 71, 73, 75, 79 Shift Register 81 Horizontal Line Edge Operation Unit 83 Vertical Line Edge Operation Unit 85 Horizontal Line Edge Feature Extraction Operation Unit 87 Vertical Line Edge Feature Extraction Operation Unit 89 Upper edge correction amount calculator 91 Lower edge correction amount calculator 93 Left edge correction amount calculator 95 Right edge correction amount calculator 97 Resolution converter 99 1-bit counter 101 Selector 103 Output determination calculator

Continuation of front page (56) References JP-A-5-177867 (JP, A) JP-A-5-278263 (JP, A) JP-A-5-131686 (JP, A) JP-A-5-95477 (JP) , A) JP-A-5-95471 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/38-1/393 G06T 1/00-1/40 G06T 3/00 -5/50 G06T 9/00-9/40 B41J 2/00-3/62

Claims (3)

(57) [Claims] 1. An image processing apparatus for converting an input image having a certain resolution into an output image subjected to a smoothing process, comprising:
A correction amount calculating means for calculating a first edge correction amount to be applied to the input image to obtain the output resolution, upon receipt of the first edge correction amount, a second output resolution of the output image that has been smoothed Resolution converting means for converting the input image into a second edge correction amount to be applied to the input image, and selectively inputting one of the first correction amount and the second correction amount and inputting the edge An image processing apparatus comprising: an output image creating unit that performs a process of applying a correction amount to the input image to create an output image having a resolution corresponding to the input edge correction amount. 2. The image processing apparatus according to claim 1, wherein the correction amount calculating unit detects a horizontal edge and a vertical edge from the input image, and increases a horizontal resolution of the input image. In order to obtain the first output resolution, the first horizontal line correction amount and the vertical line correction amount to be respectively applied to the horizontal line edge and the vertical line edge are calculated by using the detected horizontal line edge and the detected horizontal line edge. Means for calculating based on the edge of the vertical line, wherein the resolution converting means increases the vertical resolution of the output image having the first output resolution, thereby increasing the second resolution.
Calculating a second horizontal line correction amount to be applied to the edge of the horizontal line based on the first horizontal line correction amount from the correction amount calculation means, in order to obtain an output image having an output resolution of An image creating means selectively receives one of the first and second horizontal line correction amounts and receives the vertical line correction amount, and calculates the first horizontal line correction amount and the vertical line correction amount to determine the first horizontal line correction amount and the vertical line correction amount. the image processing apparatus of generating an output image of the output resolution, to generate an output image of the second output resolution from said vertical line correction amount and the second horizontal line correction amount, characterized in that. 3. An image processing apparatus according to claim 2, wherein an output image of the second output resolution is an integer multiple greater than the first output resolution in vertical resolution, for which, the first A plurality of horizontal lines corresponding to each horizontal line of the output image of the output resolution, wherein the resolution conversion means comprises: for each horizontal line of the output image of the first output resolution,
Means for generating a signal for distinguishing a plurality of horizontal lines; and determining the first horizontal line correction amount for each horizontal line of the output image of the first output resolution according to the signal for distinguishing the plurality of horizontal lines. Means for obtaining the second horizontal line correction amount by selecting whether to enable or disable the image processing apparatus.