JP6244805B2 - Image processing apparatus and image processing program - Google Patents

Description

  The present invention relates to an image processing apparatus and an image processing program.

  Patent Document 1 has an object to provide an image alignment method and a product inspection apparatus using the image alignment method that enables correction of non-linear image displacement with real-time property at low cost. And a two-dimensional inspection image (grayscale image or binary image) composed of pixels arranged in the horizontal scanning line direction and a reference image as a unit of a line block, which is a set of a certain number of lines, in a cell matching calculation unit Template matching is performed, and the matching result is quantitatively evaluated by the evaluation unit to determine whether it is valid or invalid, and the amount of positional deviation is sequentially calculated from the effective matching result, and based on the amount of positional deviation. It is disclosed that a correction operation of a comparison pixel address is performed to perform misalignment correction, and the comparison unit compares both images.

  Japanese Patent Application Laid-Open No. 2004-228561 detects a positional deviation amount required for correcting geometric distortion, and even when detecting a positional deviation amount for each of a large number of small correction target areas, the positional deviation amount is high-speed. In order to provide a captured image geometric distortion detecting device capable of detecting the image, the web is imaged by combining the main scanning by the line sensor camera and the sub-scanning by the web transfer, and for the obtained image inspection. A captured image geometric distortion detection device that detects a positional shift amount between the reference image and the inspection target image using a template for the reference image and the inspection target image, wherein the template includes a plurality of the reference image and the inspection target image. A predicted value that is arranged in each of the divided correction target areas and predicts the positional deviation amount of the other template from the positional deviation amount of the predetermined template. Narrowing the search range, to have a template matching means for fast detection of the positional deviation amount is disclosed by there.

  Patent Document 3 aims to provide an image inspection method and apparatus capable of inspecting an image by performing misalignment correction with a short processing time and high reliability, and reference pixel data in a direction to be corrected. Based on the data of the position of the pixel data string to be inspected, which extracts a column, extracts a plurality of corresponding pixel data strings to be inspected on the image to be inspected, calculates a correlation coefficient for them, and gives the maximum correlation coefficient It is disclosed that a positional deviation is corrected and compared with a reference image.

JP 09-035063 A Japanese Unexamined Patent Publication No. 2000-082135 JP 07-249122 A

  The present invention relates to an image processing apparatus and image processing in which comparison is performed with a rectangle and a movement amount in consideration of errors that may occur in the image forming apparatus or the image reading apparatus when comparing image data and read data. The purpose is to provide a program.

The gist of the present invention for achieving the object lies in the inventions of the following items.
According to the first aspect of the present invention, a receiving unit that receives image data and read data obtained by reading a medium on which the image of the image data is formed, an image forming apparatus that forms an image of the image data on the medium, or the medium is read. An extraction unit that extracts one of the image data and the read data and extracts a rectangular image into a rectangle generated based on an error that may occur in the image reading apparatus, the error , and the image data or Based on the position of the read data in one image, the extraction means determines the range of movement that determines the search range, and the search range determined by the determination means in the other image is extracted by the extraction means and search means for searching for a rectangular image that is, the difference between the first position and the second position and the rectangular image in the search result by the searching means, from the first position And position weight, an image processing apparatus characterized by comprising a comparison means for comparing the image of the search result by the rectangular image and the search unit extracted by said extraction means.

  According to a second aspect of the present invention, the error includes an affine transformation in an image forming apparatus or an image reading apparatus, and the rectangle has a pixel shift between a rectangular image of one image and a rectangular image of the other image by the affine transformation. The image processing apparatus according to claim 1, wherein is less than one pixel.

  According to a third aspect of the present invention, the error includes affine transformation in an image forming apparatus or an image reading apparatus, and the moving amount is increased in accordance with the distance from the origin in the image data or the read data, and the farthest from the origin. 3. The image processing apparatus according to claim 1, wherein the movement amount at the point is a maximum movement amount by the affine transformation in the size of the image data or the read data.

According to a fourth aspect of the present invention, there is provided a computer for receiving image data and read data obtained by reading a medium on which an image of the image data is formed, an image forming apparatus in which an image of the image data is formed on the medium, or the medium The image data or the read data is divided into one rectangle generated based on an error that can occur in the image reading apparatus that has read the image data, and an extraction unit that extracts a rectangular image, the error , and the Based on the position of the image data or the read data in one image, the extraction means determines the range of the movement amount that defines the search range, and the search range determined by the determination means in the other image and search means for searching for a rectangular image extracted by means of the difference between the first position of the rectangular image and the second position in the search result by the searching means, the A displacement from the first position, an image processing program for functioning as a comparing means for comparing the image of the search result by the rectangular image and the search unit extracted by said extraction means.

  According to the image processing apparatus of the first aspect, when comparing the image data and the read data, the comparison can be performed with a rectangle and a moving amount in consideration of an error that may occur in the image forming apparatus or the image reading apparatus. it can.

  According to the image processing apparatus of the second aspect, it is possible to use a rectangle in which the pixel shift between the rectangular image of one image and the rectangular image of the other image is within one pixel.

  According to the image processing apparatus of the third aspect, it is possible to use a movement amount that maximizes the movement amount by the affine transformation in the size of the image data or the read data.

  According to the image processing program of claim 4, when comparing the image data and the read data, the comparison can be performed with a rectangle and a moving amount in consideration of an error that may occur in the image forming apparatus or the image reading apparatus. it can.

It is a conceptual module block diagram about the structural example of this Embodiment. It is a flowchart which shows the process example by this Embodiment. It is explanatory drawing which shows the example of the magnitude | size of the search range based on the position in an image. It is explanatory drawing which shows the process example of a defect detection. It is a flowchart which shows the process example which calculates a block size and a movement amount. It is explanatory drawing which shows the process example by this Embodiment. It is explanatory drawing which shows the example of a block. It is explanatory drawing which shows the process example by a comparison and collation module. It is explanatory drawing which shows the example of a relationship between a block image and a search range. It is explanatory drawing which shows the process example which calculates a block size. It is explanatory drawing which shows the process example which calculates movement amount. It is explanatory drawing which shows the process example which calculates movement amount. It is a block diagram which shows the hardware structural example of the computer which implement | achieves this Embodiment.

Hereinafter, an example of a preferred embodiment for realizing the present invention will be described with reference to the drawings.
FIG. 1 shows a conceptual module configuration diagram of a configuration example of the present embodiment.
The module generally refers to components such as software (computer program) and hardware that can be logically separated. Therefore, the module in the present embodiment indicates not only a module in a computer program but also a module in a hardware configuration. Therefore, the present embodiment is a computer program for causing these modules to function (a program for causing a computer to execute each procedure, a program for causing a computer to function as each means, and a function for each computer. This also serves as an explanation of the program and system and method for realizing the above. However, for the sake of explanation, the words “store”, “store”, and equivalents thereof are used. However, when the embodiment is a computer program, these words are stored in a storage device or stored in memory. It is the control to be stored in the device. Modules may correspond to functions one-to-one, but in mounting, one module may be configured by one program, or a plurality of modules may be configured by one program, and conversely, one module May be composed of a plurality of programs. The plurality of modules may be executed by one computer, or one module may be executed by a plurality of computers in a distributed or parallel environment. Note that one module may include other modules. Hereinafter, “connection” is used not only for physical connection but also for logical connection (data exchange, instruction, reference relationship between data, etc.). “Predetermined” means that the process is determined before the target process, and not only before the process according to this embodiment starts but also after the process according to this embodiment starts. In addition, if it is before the target processing, it is used in accordance with the situation / state at that time or with the intention to be decided according to the situation / state up to that point. When there are a plurality of “predetermined values”, they may be different values, or two or more values (of course, including all values) may be the same. In addition, the description having the meaning of “do B when it is A” is used in the meaning of “determine whether or not it is A and do B when it is judged as A”. However, the case where it is not necessary to determine whether or not A is excluded.
In addition, the system or device is configured by connecting a plurality of computers, hardware, devices, and the like by communication means such as a network (including one-to-one correspondence communication connection), etc., and one computer, hardware, device. The case where it implement | achieves by etc. is also included. “Apparatus” and “system” are used as synonymous terms. Of course, the “system” does not include a social “mechanism” (social system) that is an artificial arrangement.
In addition, when performing a plurality of processes in each module or in each module, the target information is read from the storage device for each process, and the processing result is written to the storage device after performing the processing. is there. Therefore, description of reading from the storage device before processing and writing to the storage device after processing may be omitted. Here, the storage device may include a hard disk, a RAM (Random Access Memory), an external storage medium, a storage device via a communication line, a register in a CPU (Central Processing Unit), and the like.

  The entire image processing system including the image processing apparatus according to the present embodiment compares image data and read data. As shown in the example of FIG. 1, an image generation module 110, a recording module 120, and a read module are used. 130, a search range determination module 140, a block / movement amount calculation module 150, and a comparison / collation module 160.

  The image generation module 110 is connected to the recording module 120, the search range determination module 140, and the comparison / collation module 160. The image generation module 110 converts the print data 105 into a print image 115 that is image data. This conversion processing includes image conversion processing necessary for printing including rasterization and color space conversion. A process of converting print data 105 described in PDL such as PDF (Portable Document Format) (registered trademark) into a raster image (print image 115) that can be recorded on a medium (paper) by a printer or a printer is performed. As an implementation form, there are dedicated hardware and software that operates on a computer such as a general-purpose PC (Personal Computer). The print image 115 as the processing result is transferred to the recording module 120, the search range determination module 140, and the comparison / collation module 160.

The recording module 120 is connected to the image generation module 110 and the reading module 130. The recording module 120 records the print image 115 on the recording medium 125. That is, the image of the image data is formed on the recording medium 125 that is a medium. The recording module 120 is realized as a printer that is an image forming apparatus.
The reading module 130 is connected to the recording module 120, the search range determination module 140, and the comparison / collation module 160. The reading module 130 converts the print image 115 on the recording medium 125 into a read image 135 by photoelectric conversion or the like. That is, a read image 135 that is read data obtained by reading the recording medium 125 is generated. This is so-called scanning processing, and the reading module 130 is realized as a scanner which is an image reading apparatus. The read image 135 is transferred to the search range determination module 140 and the comparison / collation module 160.

  The search range determination module 140 is connected to the image generation module 110, the reading module 130, the block / movement amount calculation module 150, and the comparison / collation module 160. The search range determination module 140 includes errors and images that can be generated by the recording module 120 in which the image of the print image 115 is formed on the recording medium 125 or the reading module 130 that has read the recording medium 125 (either the print image 115 or the read image 135). However, the range of the movement amount that determines the search range is determined based on the position within the range. “Errors that may occur in the recording module 120 or the reading module 130” will be described later in the description of the block / movement amount calculation module 150. For example, the search range determination module 140 increases the amount of movement according to the distance from the origin in the print image 115 or the read image 135, and the amount of movement at the farthest point from the origin corresponds to the print image 115 or the read image 135. The size is calculated so that the amount of movement due to affine transformation, which is an error that may occur in the recording module 120 or the reading module 130, is maximized. Note that the distance from the origin is the same value as the block position. The origin of the print image 115 or the read image 135 is a position where the occurrence of an error in the recording module 120 or the read module 130 is minimum, and refers to the coordinates of the upper left corner of the image, for example. The “farthest point from the origin” is the farthest position from the origin. The farthest position from the origin is the position where the error of the recording module 120 or the reading module 130 is the largest, and refers to, for example, the coordinates of the lower right corner of the image. Specifically, the search range determination module 140 increases the size of the search range from the coordinates of the upper left corner toward the coordinates of the lower right corner. The maximum size is determined by the maximum value of “error that can occur in the recording module 120 or the reading module 130” and is the movement amount 154 calculated by the block / movement amount calculation module 150.

  This will be described with reference to the example of FIG. FIG. 3 is an explanatory diagram showing an example of the size of the search range based on the position in the image. The example of FIG. 3A shows an example of the positions of the origin 310 (upper left corner) and the farthest point 390 (lower right corner) in the image 300. The example in FIG. 3B shows the relationship between the block 312 and the search range 314 at the origin 310. The search range 314 is larger than the block 312 by a predetermined value (0 or more). The example of FIG. 3C shows the relationship between the block 392 and the search range 394 at the farthest point 390. The search range 394 has a size determined by the movement amount 154 calculated by the block / movement amount calculation module 150. The block 312 and the block 392 have the same size, and the block size 152 calculated by the block / movement amount calculation module 150. Here, the upper left corner is shown as the origin, and the lower right corner is shown as the farthest point, but there are four points (lower right corner, upper right corner, lower left corner) depending on the nature of errors that may occur in the recording module 120 or the reading module 130. , Upper left corner). In this example, the rotation of the recording module 120 or the reading module 130 occurs around the upper left corner, and the effect of the enlargement / reduction increases as the distance from the upper left corner increases.

The comparison / collation module 160 is connected to the image generation module 110, the reading module 130, and the search range determination module 140. The comparison / collation module 160 compares and collates the print image 115 and the read image 135 to detect the presence / absence of a defect and the occurrence area. The comparison / collation module 160 receives the print image 115 and the read image 135. The read image 135 is obtained by reading the recording medium 125 on which the print image 115 is formed. That is, an original print image 115 to be printed out and a read image 135 obtained by printing out the print image 115 and scanning the printed recording medium 125 are received. This is for checking the presence or absence of defects generated by the recording module 120 and the reading module 130. Here, the defect is referred to as noise, and ideally, the printed image 115 and the read image 135 completely coincide. However, a defect may occur depending on the maintenance status of the recording module 120 and the reading module 130. Note that an error may occur in the recording module 120 and the reading module 130. Here, the “error that can occur” is an error allowed in the design specifications of the recording module 120 and the reading module 130. Specific examples of the error include affine transformation of enlargement / reduction, rotation, and movement. As an error, for example, when a design specification in which rotation does not occur more than x degrees is realized (a design target is achieved), rotation less than x degrees can occur.
Therefore, the comparison / collation module 160 attempts to extract defects (for example, black pixel mixture of 3 pixels or more) excluding errors that may occur in the recording module 120 and the reading module 130. In other words, it is confirmed whether or not a defect other than the error allowed in the design specification has occurred, and the position where the defect has occurred is specified, so as to be useful for maintenance of the recording module 120 and the reading module 130. To do.

The comparison / collation module 160 divides one image of the print image 115 or the read image 135 into a rectangle (hereinafter also referred to as a block) generated based on an error that may occur in the recording module 120 or the reading module 130. Extract a rectangular image. One image may be either the print image 115 or the read image 135. Hereinafter, the print image 115 will be described as one image, and the read image 135 will be described as the other image. Block division will be described with reference to FIG. FIG. 6 is an explanatory diagram showing a processing example according to the present embodiment. In the example of FIG. 6A, the reference image 600a is divided into 9 × 12 blocks. Of course, the number of divisions varies depending on the block size and the size of the reference image 600a. Further, depending on the relationship between the block size and the size of the reference image 600a, it is not always possible to divide by an integer number. However, for example, an image of white or the like may be added to a portion less than one block. Further, the block size 152 is received from the block / movement amount calculation module 150 and is divided into blocks.
FIG. 7 is an explanatory diagram showing a block example, and is an enlarged display of the block image 610a shown in the example of FIG. The block image 610a has a size of W _p × H _p . The coordinates of the center pixel 710 of the block image 610a are set to (C _x , C _y ).

Next, the comparison / collation module 160 searches for the extracted rectangular image in the search range determined by the search range determination module 140 in the other image. For example, FIG. 6B shows an example of searching for the block image 610a shown in FIG. As shown in FIG. 6B, the block image 610a is searched in the search range 650b which is the “movement amount range” in the read image 600b. Note that the block image 610b in the read image 600b corresponds to the block image 610a in the reference image 600a. Ideally (when the error that can occur in the recording module 120 and the reading module 130 is 0), it is only necessary to compare the block image 610a and the block image 610b in order to detect a defect. Actually, since there is an error that can occur in the recording module 120 and the reading module 130, the search is performed within the search range 650b in consideration of the error. Thus, it is not necessary to search the entire read image 600b, and a position that matches the block image 610a in the read image 600b can be found. The search range is a region that includes the rectangle of the other image at the same position as the rectangle in one image, and is formed by the amount of movement up, down, left, and right around that rectangle.
The search process will be described with reference to FIG. FIG. 8 is an explanatory diagram showing an example of processing by the comparison / collation module 160. The example shown in FIG. 8 is an enlarged display of the search range 650b shown in the example of FIG. Within the search range 650b of the read image 600b, the block image 610a of the reference image 600a is moved pixel by pixel to perform template matching. Then, as a result of the template matching, the relative position with respect to the block image from which the maximum score indicating the closest approximation within the search range is obtained is defined as a displacement amount 820. That is, the block image 610b corresponds to the block image 610a in the search range 650b. As a result of performing template matching between the block image in the search range 650b and the block image 610a, the block image 830 at the maximum score position is obtained. When extracted, the displacement amount is 820. Further, the search range 145 is received from the search range determination module 140, and the target block is searched.

  Next, the comparison / collation module 160 uses the position in the search result as a displacement, and compares the extracted rectangular image with the image of the search result. The “search result” is the result of comparing the rectangular images in one image within the search range of the other image and extracting the position where the two match most. The difference between the position and the position of the rectangular image may be used as the displacement amount. A search result may be used for “compare”. That is, since the search result is the best match, the degree of match may be the defect detection result 165. Further, the defect detection result 165 may include a displacement amount in addition to the matching degree.

  This will be described with reference to FIG. FIG. 4 is an explanatory diagram showing a processing example of defect detection by the comparison / collation module 160. A print block image 410 shown in the example of FIG. 4A is a block image in the print image 115, a read block image 420 shown in the example of FIG. 4B is a block image in the read image 135, and The difference block image 430 shown in the example of FIG. 4C is a difference (result of exclusive OR processing) between the print block image 410 and the read block image 420. The comparison / collation module 160 generates a difference image for each block and detects a defect in the difference image. As the defect, for example, it may be detected that the size of one side of the circumscribed rectangle is in a predetermined range (for example, 3 to 5 pixels).

  The block / movement amount calculation module 150 is connected to the search range determination module 140. The block / movement amount calculation module 150 calculates a block size 152 and a movement amount 154 based on errors that may occur in the recording module 120 or the reading module 130. Then, the block size 152 and the movement amount 154 are passed to the search range determination module 140. The error of the recording module 120 or the reading module 130 includes affine transformation in the image forming apparatus or the image reading apparatus. Specific examples of the error include an enlargement / reduction ratio and a rotation angle. The processing by the block / movement amount calculation module 150 may be performed before the search range determination module 140 performs processing, and is calculated in advance, and the block size 152 and the movement amount 154 are stored in the search range determination module 140. You may do it. Further, in order to correspond to the recording module 120 and the reading module 130 used at that time, an error is received from the recording module 120 and the reading module 130, and the block size 152 and the movement amount 154 are calculated each time. Good.

The block size 152 is determined by affine transformation so that the pixel shift between the rectangular image of one image and the rectangular image of the other image is within one pixel. The calculation of the block size 152 will be described later using the example of FIG.
The movement amount 154 calculated by the block / movement amount calculation module 150 is determined so that the movement amount by the affine transformation is maximized in the size of the print image 115 or the read image 135. The movement amount 154 is for forming the search range 650b. FIG. 9 is an explanatory diagram illustrating a relationship example between the block image 610a and the search range 650b. Specifically, the movement amount 154 is an upward movement amount, a downward movement amount, a leftward movement amount, and a rightward movement amount.
The vertical (block height) of the block image 610a is L _a + 1 + L _b, which is H _p shown in the example of FIG.
The width (block width) of the block image 610a is L ₁ + 1 + L _r, which is W _p shown in the example of FIG.
The vertical length (search range height) of the search range 650b is H _p + L _a + L _b . L _a is a upward movement amount. L _b is a downward movement amount.
Width of the search range 650b (search range width) _is a _{W p + L l + L r} . L ₁ is the leftward movement amount. _Lr is the amount of rightward movement.
The calculation of the movement amount 154 will be described later using the examples of FIGS.
Further, the movement amount 154 indicates the maximum value of the search range in the image, and the search range determination module 140 determines the search range 145 based on the position of the block in the image using the movement amount 154. .

FIG. 2 is a flowchart showing an example of processing according to this embodiment.
In step S <b> 202, the image generation module 110 converts the print data 105 to generate a print image 115.
In step S <b> 204, the recording module 120 records the print image 115 on the recording medium 125.
In step S206, the reading module 130 reads the recording medium 125 on which the print image 115 is recorded.
In step S208, the search range determination module 140 determines a search range 145 for each block.
In step S210, the comparison / collation module 160 compares and collates the converted image (printed image 115) and the read image 135 to detect a defect occurrence area.

FIG. 5 is a flowchart illustrating a processing example in which the block / movement amount calculation module 150 calculates the block size 152 and the movement amount 154.
In step S502, the enlargement / reduction ratio and rotation angle (skew angle) that can occur in the recording module 120 and the reading module 130 are acquired.
In step S504, the block size is calculated.
In step S506, the movement amount is calculated.
In step S508, the block size 152 and the movement amount 154 are transferred to the search range determination module 140 and the comparison / collation module 160.

FIG. 10 is an explanatory diagram illustrating an example of processing for calculating the block size 152. When rotation and enlargement / reduction by the recording module 120 and the reading module 130 all occur in the worst state, the pixel shift at each corner when the block of the print image 115 and the block of the read image 135 are aligned is within one pixel. Set the block size so that
The example of FIG. 10 shows how the point 1050 in the print image 115 is shifted due to errors in the recording module 120 and the reading module 130.
Point 1050 moves to point 1060 due to movement due to enlargement / reduction (at the time of maximum reduction in both scanning directions) 1055. Further, the point moves to a point 1070 by a movement (counterclockwise) 1065 due to skew. This is the case where the maximum reduction (when it becomes the smallest) and the counterclockwise rotation become the maximum.
The point 1050 moves to the point 1040 by the movement due to enlargement / reduction (at the time of maximum enlargement in both scanning directions) 1045. Further, the point moves to a point 1030 by a movement (clockwise) 1035 due to skew. This is the case where the maximum enlargement (when it becomes the largest) and the clockwise rotation become the maximum.

この点を通る直線と元の直線でｙ＝１のときのｘの差分△ｘを計算する。図１０の例では、差分△ｘは、点１０５０、原点と点１０７０を通る直線、ｙ＝１の直線によって定まる。 (1) In both scanning directions, when the maximum reduction (x-axis direction magnification: r ₁ , y-axis direction magnification: r ₂ ) and skew maximum (counterclockwise, rotation angle α), the block moves most from the origin. When the amount of movement of the point on the diagonal line having the large amount is calculated by (1, 1), the equation (1) is obtained.

The difference Δx of x when y = 1 between the straight line passing through this point and the original straight line is calculated. In the example of FIG. 10, the difference Δx is determined by a point 1050, a straight line passing through the origin and the point 1070, and a straight line with y = 1.

この点を通る直線と元の直線でｘ＝１のときのｙの差分△ｙを計算する。図１０の例では、差分△ｙは、点１０５０、原点と点１０３０を通る直線、ｘ＝１の直線によって定まる。
（３）△ｘ、△ｙが１．４となるｙ’、ｘ’を計算する。そして、ブロックの幅、高さをＷ、Ｈとすると、式（３）のようになる。

なお、ｃｅｉｌ（）は小数点以下を切り上げする関数である。
これによって、ブロックサイズ１５２（式（３）のＷ、Ｈ）が算出できる。例えば、ブロックの幅、高さとして、それぞれ１００画素、１１０画素等となる。 (2) On the other hand, when the maximum magnification in both scanning directions (x-axis direction magnification: r ₃ , y-axis direction magnification: r ₄ ) and skew maximum (clockwise, rotation angle β), the movement amount is the largest with the block center as the origin. When the amount of movement of the point on the diagonal line with a large is calculated by (1, 1), the following equation (2) is obtained.

The difference Δy of y when x = 1 between the straight line passing through this point and the original straight line is calculated. In the example of FIG. 10, the difference Δy is determined by a point 1050, a straight line passing through the origin and the point 1030, and a straight line with x = 1.
(3) Calculate y ′ and x ′ such that Δx and Δy are 1.4. When the width and height of the block are W and H, the equation (3) is obtained.

Note that ceil () is a function that rounds up after the decimal point.
As a result, the block size 152 (W, H in equation (3)) can be calculated. For example, the width and height of the block are 100 pixels and 110 pixels, respectively.

ただし、Ｍ_ｓｋｅｗはスキューによる移動量、Ｍ_ｓｉｚｅは拡縮による移動量、Ｍ_{ｓｈｉｆｔ}はシフトによる移動量である。
ここで、Ｍ_ｓｋｅｗ、Ｍ_ｓｉｚｅ、Ｍ_{ｓｈｉｆｔ}は、それぞれ式（５）、式（６）、式（７）のようになる。

なお、γは回転角度、ｒ_５、ｒ_６は拡大縮小率、ｓ_１、ｓ_２は移動量である。
したがって、式（８）のようになる。

図１１の例を用いて説明する。図１１は、移動量を算出する処理例を示す説明図である。
点１１５０が、シフトによる移動（右上方向に最大）１１５５によって点１１６０へ移動する。さらに、拡縮による移動（主走査方向最大拡大、副走査方向最大縮小時）１１６５によって点１１７０に移動する。さらに、スキューによる移動（反時計回り）１１７５によって点１１８０に移動する。つまり、画像１１００の原点１１１０（図１１では左上隅）から最遠地点（右下隅）での、上方向、右方向への最大移動量を算出している。 Next, a processing example for calculating the movement amount 154 (search range size) will be described using the examples of FIGS. The movement amount 154 calculated here is the movement amount at the farthest point.
When the rotation, enlargement / reduction, and movement by the recording module 120 and the reading module 130 all occur in the worst state, the movement amount 154 is set so that the movement amount at the lower right corner can be considered in a certain paper size (for example, A Nobi paper). Set. In the following coordinates, the upper left corner is the origin, the right / down direction is the positive value direction, and the rotation angle is clockwise the positive value direction.
Under the condition that the amount of movement is the maximum in the upper right direction, the lower right corner with the largest amount of movement with the upper left corner at a certain paper size as the origin (for example, the coordinates (3897, 5763) at 300 dpi for A3 paper) When the quantity is calculated, the equation (4) is obtained.

However, M _skew is the amount of movement due to _skew , M _size is the amount of movement due to expansion / contraction, and M _shift is the amount of movement due to _shift .
Here, M _skew , M _size , and M _shift are as shown in Equation (5), Equation (6), and Equation (7), respectively.

Γ is a rotation angle, r ₅ and r ₆ are enlargement / reduction ratios, and s ₁ and s ₂ are movement amounts.
Therefore, it becomes like Formula (8).

This will be described with reference to the example of FIG. FIG. 11 is an explanatory diagram illustrating a processing example for calculating the movement amount.
Point 1150 is moved to point 1160 by a shift (maximum in the upper right direction) 1155 due to the shift. Further, it moves to a point 1170 by a movement 1165 (maximum enlargement in the main scanning direction and maximum reduction in the sub-scanning direction) 1165. Further, it moves to a point 1180 by a movement (counterclockwise) 1175 due to skew. That is, the maximum amount of movement in the upward and right directions from the origin 1110 (upper left corner in FIG. 11) of the image 1100 to the farthest point (lower right corner) is calculated.

なお、θは回転角度、ｒ_７、ｒ_８は拡大縮小率、ｓ_３、ｓ_４は移動量である。
したがって、式（１２）のようになる。

図１２の例を用いて説明する。図１２は、移動量を算出する処理例を示す説明図である。
点１１５０が、シフトによる移動（左下方向に最大）１１４５によって点１１４０へ移動する。さらに、拡縮による移動（主走査方向最大縮小、副走査方向最大拡大時）１１３５によって点１１３０に移動する。さらに、スキューによる移動（時計回り）１１２５によって点１１２０に移動する。つまり、画像１１００の原点１１１０（図１２では左上隅）から最遠地点（右下隅）での、下方向、左方向への最大移動量を算出している。 On the other hand, when the movement amount of the lower right corner (for example, A3 Nobi paper) having the largest movement amount is calculated with the upper left corner at a certain paper size as the origin under the condition that the movement amount is maximum in the lower left direction, Equation (9) (10) and (11).

Note that θ is a rotation angle, r ₇ and r ₈ are enlargement / reduction ratios, and s ₃ and s ₄ are movement amounts.
Therefore, it becomes like a formula (12).

This will be described with reference to the example of FIG. FIG. 12 is an explanatory diagram illustrating a processing example for calculating the movement amount.
Point 1150 moves to point 1140 by a shift 1145 (maximum in the lower left direction) due to the shift. Furthermore, the point moves to a point 1130 by a movement 1135 (maximum reduction in the main scanning direction and maximum enlargement in the sub-scanning direction) 1135. Further, the movement to the point 1120 is performed by the movement (clockwise) 1125 due to the skew. That is, the maximum amount of movement in the downward and left directions from the origin 1110 (upper left corner in FIG. 12) of the image 1100 to the farthest point (lower right corner) is calculated.

  From the above, the upward maximum value, downward maximum value, leftward maximum value, and rightward maximum value of the movement amount may be calculated. For example, 67.41 pixels, 95.99 pixels, 58.73 pixels, and 62.47 pixels, respectively, and the amount of movement in the vertical and horizontal directions of the block is 68 pixels, 96 pixels, 59 pixels, and 63 pixels, respectively. . Actually, the recording module 120 and the reading module 130 may be out of specification (spec over), and therefore the movement amount may be set larger by a predetermined value. This value is the amount of movement at the point 1150 which is the farthest point from the origin 1110. The search range determination module 140 determines the movement amount (search range) at a position other than the point 1150 based on the position and the movement amount at the point 1150.

  A hardware configuration example of the image processing apparatus according to the present embodiment will be described with reference to FIG. The configuration shown in FIG. 13 is configured by a personal computer (PC), for example, and shows a hardware configuration example including a data reading unit 1317 such as a scanner and a data output unit 1318 such as a printer.

  A CPU (Central Processing Unit) 1301 includes various modules described in the above-described embodiments, that is, each of the search range determination module 140, the comparison / collation module 160, the image generation module 110, the block / movement amount calculation module 150, and the like. It is a control part which performs the process according to the computer program which described the execution sequence of a module.

  A ROM (Read Only Memory) 1302 stores programs used by the CPU 1301, calculation parameters, and the like. A RAM (Random Access Memory) 1303 stores programs used in the execution of the CPU 1301, parameters that change as appropriate during the execution, and the like. These are connected to each other by a host bus 1304 including a CPU bus.

  The host bus 1304 is connected to an external bus 1306 such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge 1305.

  A keyboard 1308 and a pointing device 1309 such as a mouse are input devices operated by an operator. The display 1310 includes a liquid crystal display device or a CRT (Cathode Ray Tube), and displays various types of information as text or image information.

  An HDD (Hard Disk Drive) 1311 has a built-in hard disk, drives the hard disk, and records or reproduces a program executed by the CPU 1301 and information. The hard disk stores print data 105, print image 115, read image 135, search range 145, block size 152, movement amount 154, defect detection result 165, and the like. Further, various computer programs such as various other data processing programs are stored.

  The drive 1312 reads data or a program recorded on a removable recording medium 1313 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and reads the data or program into an interface 1307 and an external bus 1306. , The bridge 1305, and the RAM 1303 connected via the host bus 1304. The removable recording medium 1313 can also be used as a data recording area similar to a hard disk.

  The connection port 1314 is a port for connecting the external connection device 1315 and has a connection unit such as USB and IEEE1394. The connection port 1314 is connected to the CPU 1301 and the like via the interface 1307, the external bus 1306, the bridge 1305, the host bus 1304, and the like. A communication unit 1316 is connected to a communication line and executes data communication processing with the outside. The data reading unit 1317 is, for example, a scanner, and executes document reading processing. The data output unit 1318 is, for example, a printer, and executes document data output processing.

  Note that the hardware configuration of the image processing apparatus illustrated in FIG. 13 shows one configuration example, and the present embodiment is not limited to the configuration illustrated in FIG. 13, and the modules described in the present embodiment are executed. Any configuration is possible. For example, some modules may be configured with dedicated hardware (for example, Application Specific Integrated Circuit (ASIC), etc.), and some modules are in an external system and connected via a communication line Alternatively, a plurality of systems shown in FIG. 13 may be connected to each other via communication lines so as to cooperate with each other. Further, it may be incorporated in a copying machine, a fax machine, a scanner, a printer, a multifunction machine (an image processing apparatus having any two or more functions of a scanner, a printer, a copying machine, a fax machine, etc.).

  The present embodiment may be an image processing apparatus including the search range determination module 140 and the comparison / collation module 160, and also includes a block / movement amount calculation module 150, a reading module 130, a recording module 120, and an image generation module. 110 may be included.

The program described above may be provided by being stored in a recording medium, or the program may be provided by communication means. In that case, for example, the above-described program may be regarded as an invention of a “computer-readable recording medium recording the program”.
The “computer-readable recording medium on which a program is recorded” refers to a computer-readable recording medium on which a program is recorded, which is used for program installation, execution, program distribution, and the like.
The recording medium is, for example, a digital versatile disc (DVD), which is a standard established by the DVD Forum, such as “DVD-R, DVD-RW, DVD-RAM,” and DVD + RW. Standard “DVD + R, DVD + RW, etc.”, compact disc (CD), read-only memory (CD-ROM), CD recordable (CD-R), CD rewritable (CD-RW), Blu-ray disc ( Blu-ray (registered trademark) Disc), magneto-optical disk (MO), flexible disk (FD), magnetic tape, hard disk, read-only memory (ROM), electrically erasable and rewritable read-only memory (EEPROM (registered trademark)) )), Flash memory, Random access memory (RAM) SD (Secure Digital) memory card and the like.
The program or a part of the program may be recorded on the recording medium for storage or distribution. Also, by communication, for example, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a wired network used for the Internet, an intranet, an extranet, etc., or wireless communication It may be transmitted using a transmission medium such as a network or a combination of these, or may be carried on a carrier wave.
Furthermore, the program may be a part of another program, or may be recorded on a recording medium together with a separate program. Moreover, it may be divided and recorded on a plurality of recording media. Further, it may be recorded in any manner as long as it can be restored, such as compression or encryption.

DESCRIPTION OF SYMBOLS 105 ... Print data 110 ... Image generation module 115 ... Print image 120 ... Recording module 125 ... Recording medium 130 ... Reading module 135 ... Read image 140 ... Search range determination module 145 ... Search range 150 ... Block and movement amount calculation module 152 ... Block Size 154 ... Movement amount 160 ... Comparison / collation module 165 ... Defect detection result

Claims (4)

Receiving means for receiving image data and read data obtained by reading a medium on which an image of the image data is formed;
One image of the image data or the read data is divided into rectangles generated based on errors that can occur in an image forming apparatus that forms an image of the image data on the medium or an image reading apparatus that reads the medium. Extracting means for extracting a rectangular image;
The error, and a determining means for the image data or on the basis of the position in one image of the scanned data, to determine the range of movement amount to determine the search range,
Search means for searching for a rectangular image extracted by the extraction means in a search range determined by the determination means in the other image;
The difference between the second position in the search result by the search means and the first position of the rectangular image is set as a displacement amount from the first position , and the rectangular image extracted by the extraction means and the search means An image processing apparatus comprising comparison means for comparing an image as a search result. As the error, including affine transformation in an image forming apparatus or an image reading apparatus,
The image processing apparatus according to claim 1, wherein a pixel shift between the rectangular image of one image and the rectangular image of the other image is within one pixel due to the affine transformation. As the error, including affine transformation in an image forming apparatus or an image reading apparatus,
The amount of movement is increased in accordance with the distance from the origin in the image data or read data, and the amount of movement at the farthest point from the origin is the amount of movement by the affine transformation in the size of the image data or the read data. The image processing device according to claim 1, wherein the image processing device is maximized. Computer
Receiving means for receiving image data and read data obtained by reading a medium on which an image of the image data is formed;
One image of the image data or the read data is divided into rectangles generated based on errors that can occur in an image forming apparatus that forms an image of the image data on the medium or an image reading apparatus that reads the medium. Extracting means for extracting a rectangular image;
The error, and a determining means for the image data or on the basis of the position in one image of the scanned data, to determine the range of movement amount to determine the search range,
Search means for searching for a rectangular image extracted by the extraction means in a search range determined by the determination means in the other image;
The difference between the second position in the search result by the search means and the first position of the rectangular image is set as a displacement amount from the first position , and the rectangular image extracted by the extraction means and the search means An image processing program for functioning as a comparison means for comparing an image of a search result.

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