JP4936472B2 - Image processing device - Google Patents

Description

  The present invention relates to an image processing apparatus that performs image reduction processing.

  2. Description of the Related Art Conventionally, an image processing apparatus such as a copying machine or a multi-function machine that executes document reduction processing is known. Such an image processing apparatus reads an image of a document to acquire image data, and then reduces the image based on the reduction magnification and outputs reduced image data (see, for example, Patent Document 1 below).

By using such an image processing apparatus, for example, a reduction copy process for performing printing based on the reduced image data on an output sheet having a size smaller than the original size, or reducing a plurality of original images. It is possible to execute layout copy processing for laying out and printing each obtained reduced image data on one output sheet.
JP-A-6-99615

  However, in the above-described conventional image processing apparatus, in a reduced image output in a reduced size, characters may become too small to be readable. In this case, there is a problem that the reduction magnification must be changed and the process is executed again, which takes time and effort, and consumables such as output paper, ink, and toner are wasted.

  Therefore, an image processing apparatus that can avoid useless output has been desired.

  The present invention adopts the following configuration in order to solve the above points.

<Constitution>
An image processing apparatus according to the present invention generates and outputs reduced image data of a reduced image obtained by reducing an original image based on the input source image data and an input unit that inputs the original image data of the original image. A reduction output unit for detecting, in the input original image data, a detection unit for detecting a straight path, a specification unit for specifying a specific pixel included in the original image data based on the detected linear path, Based on the total number of pixels of the original image data and the specific number of pixels of the specified specific pixel, a calculation unit that calculates a ratio value indicating the ratio of the specific pixel number to the total number of pixels, and based on the calculated ratio value Thus, a determination unit that determines the readability of the reduced image data and a notification unit that notifies the determination result when it is determined that the reduced image data is not readable are provided.

  According to the image processing apparatus of the present invention, specific pixels are specified in the original image data, and the readability of the reduced image is determined based on the ratio of the specific pixel number to the total pixel number. If it is determined that the readability is low, the low readability is notified before the printout is performed, so that the output of the reduced image with low readability can be stopped. Therefore, useless output can be avoided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a copying apparatus will be described as an example.

FIG. 2 is an external view of the copying apparatus according to the present invention.
The copying apparatus 10 has a document copying function, and includes a reading unit 11, an operator panel unit 12, and a printing unit 13, as shown in FIG.

  The reading unit 11 includes a placing table for placing a document, and a reading sensor such as a CCD sensor installed below the placing table, and optically images the document placed on the placing table. And converting it into an electrical signal to generate image data.

  The operator panel unit 12 is an operation panel having, for example, a display device such as an LCD display or LED and an input device such as a switch or a numeric keypad. Or input.

  The printing unit 13 includes a photosensitive drum on which an electrostatic latent image based on the image data generated by the reading unit 11 is formed, and the electrostatic latent image is copied with toner to form an image on recording paper.

Next, the functional configuration of the copying apparatus 10 of this embodiment will be described.
FIG. 1 is a block diagram illustrating a functional configuration of the copying apparatus according to the first embodiment of the present invention.
As illustrated in FIG. 1, the copying apparatus 10 according to the present exemplary embodiment includes a reading unit 11, an image data storage unit 14, a reduction unit 15, a printing unit 13, a binarization processing unit 16, and a straight line detection unit. 17, a specification unit 18, a pixel number storage unit 19, a calculation unit 20, a readability determination unit 21, and an operator panel unit 12.

  For example, in the case of monochrome, the reading unit 11 inputs image data as original image data generated by reading a document with halftone gradation and stores the image data in the image data storage unit 14.

  The image data storage unit 14 includes a storage device such as a hard disk or a RAM, and is a storage unit that stores various image data. The image data storage unit 14 stores image data as original image data and binary image data described later.

  The reduction unit 15 is a processing unit that performs image reduction processing based on a specified reduction magnification as a reduction output unit, and generates reduced image data based on image data stored in the image data storage unit 14. The reduced image data is output to the printing unit 13 as print image data.

  The printing unit 13 performs printing based on the printing image data.

  As an input unit, the binarization processing unit 16 performs binarization processing on the image data stored in the image data storage unit 14 with a predetermined threshold to generate binary image data, and the image data storage unit 14 Remember me. Here, the binary image data is image data in which the pixel value of each pixel is either “0” or “1”. Hereinafter, a pixel having a pixel value “0” is referred to as a white pixel, and a pixel having a pixel value “1” is referred to as a black pixel.

  The straight line detection unit 17 has a function as a detection unit that detects a straight line path in the binary image data. The straight line detection unit 17 performs a pixel search along a boundary, that is, an edge between a white region composed of white pixels and a black region composed of black pixels in the binary image data stored in the image data storage unit 14, An edge that is a straight line in the main scanning direction or the sub-scanning direction is detected as a straight path.

  The specifying unit 18 specifies a deteriorated pixel as a specific pixel based on the straight line path detected by the straight line detecting unit 17. The identifying unit 18 determines whether or not the detected linear path has distortion due to image degradation. When the identifying unit 18 determines that there is distortion, the identifying unit 18 identifies each pixel in the distortion part as a degraded pixel. And the specific | specification part 18 counts the pixel number of the specified deterioration pixel.

The pixel number storage unit 19 includes a storage device such as a hard disk or a RAM, and stores the number of deteriorated pixels in the binary image data as the deteriorated pixel number n. The pixel number storage unit 19 further stores the total number of pixels n ₀ of the binary image data.

The calculation unit 20 calculates a ratio value r indicating the ratio of the number of deteriorated pixels to the total number of pixels in the binary image data based on the total number of pixels n ₀ and the number of deteriorated pixels n stored in the pixel number storage unit 19. , Based on the calculation formula r = n / n ₀ .

As the determination unit, the readability determination unit 21 determines the readability of the image after the reduction process, that is, the reduced image, based on the ratio value r calculated by the calculation unit 20. Readability judging unit 21 preliminarily stores a predetermined ratio threshold r _th, when the ratio value r is less than or equal to said ratio threshold r _th, the reduced image is determined to be readable, reduction of the image to the reduction section 15 Instruct. When the ratio value r is larger than the ratio threshold value r _th , the readability determination unit 21 determines that the readability of the reduced image is low, that is, is not readable, and instructs the operator panel unit 12 to display a warning screen.

As the notification unit, the operator panel unit 12 displays a warning screen for warning the low readability of the reduced image on the display device.
FIG. 3 is an explanatory diagram illustrating a display example of a warning screen.

  Further, the operator panel unit 12 performs input of magnification information for designating a reduction magnification of an image, a forced execution request for requesting forced execution of reduced printing, an execution stop request for requesting cancellation of reduced printing, and the like.

Next, the operation of the copying apparatus 10 of this embodiment will be described.
The copying apparatus 10 detects a straight path in the image data and identifies a deteriorated pixel. Here, the flow of detecting the straight path and identifying the deteriorated pixel will be described with reference to the flowchart shown in FIG.
FIG. 4 is a flowchart showing the detection specifying operation of the copying apparatus according to the present invention.

  In the copying apparatus 10, the straight line detection unit 17 instructs the binarization processing unit 16 to binarize image data when receiving a straight path detection instruction.

  Based on this binarization instruction, the binarization processing unit 16 reads out the image data stored in the image data storage unit 14, performs binarization processing on the image data, and converts it to binary image data. (Step S101). Here, the image data to be binarized is data input by the reading unit 11. Each pixel value of the binary image data is “0” or “1”. The binary image data generated by the binarization processing unit 16 is stored in the image data storage unit 14.

  Next, the straight line detection unit 17 sets each pixel (i, j) in the binary image data as a target pixel in the binary image data so as to detect a straight path in the main scanning direction or the sub-scanning direction. The following processing is performed on (i, j). Here, i indicates the position in the main scanning direction of the pixel of interest in the binary image data, and j indicates the position in the sub-scanning direction.

First, the straight line detection unit 17 adds 1 to the total number of pixels n ₀ stored in the pixel number storage unit 19 in order to count the total number of pixels of the binary image data, and sets the total number of pixels to n ₀ +1. (Step S102). The total number of pixels n ₀ stored in the number-of-pixels storage unit 19 is initialized prior to the execution of the detection specifying process (described later). Therefore, by adding 1, the total number of pixels is n ₀ = 1. It becomes.

  Subsequently, the straight line detection unit 17 determines whether or not the target pixel (i, j) is a start point pixel that is in contact with the start point of the pass (step S103). In the straight line detection unit 17, a pixel value pattern of 3 × 3 pixels around the start point pixel is stored in advance as a start point pattern. The straight line detection unit 17 compares these start point patterns with the pixel value pattern of 3 × 3 pixels around the target pixel (i, j), and determines whether the target pixel (i, j) is the start point pixel. Is determined (step S103).

FIG. 5 is an explanatory diagram showing a start point pattern.
The straight line detection unit 17 stores in advance the eight start point patterns shown in FIG. A numerical value included in each starting point pattern represents a pixel value. That is, the area indicated by the numerical value “0” represents a white pixel, and the area indicated by the numerical value “1” is a black pixel. The data “*” indicates that either “0” or “1” may be used.

  Further, in each starting point pattern shown in FIG. 5, the position indicated by the symbol “◯” is the starting point of the path. The straight line detection unit 17 obtains the pixel value of 3 × 3 pixels around the pixel of interest (i, j) using the pixel indicated by the symbol “Δ” in FIG. 5 as the pixel of interest (i, j). The pixel value pattern and each start point pattern are compared to determine whether or not they match. If it matches any of the start point patterns, the straight line detection unit 17 determines that the target pixel (i, j) is the start point pixel. If it does not match any of the start point patterns, the straight line detection unit 17 determines that the target pixel (i, j) is not the start point pixel.

  When it is determined that the pixel of interest (i, j) is the start point pixel (step S103), the straight line detection unit 17 detects the path from the position of the start point “◯” as indicated by an arrow in FIG. A pixel search is performed along the edge, that is, the boundary between the white pixel “0” and the black pixel “1” (step S104).

  During this pixel search, if the path search direction is reversed by 180 degrees, or if the pixel value pattern of the surrounding pixels matches the pre-stored exclusion pattern, the straight line detection unit 17 is detected. It is determined that the path is not a straight path, that is, a non-linear path (step S105), the search for the path is terminated, and the path is excluded from the straight path.

FIG. 6 is an explanatory diagram showing an exclusion pattern.
If the pixel value pattern of 2 × 2 pixels around the detected path matches the exclusion pattern shown in FIG. 6, the straight line detection unit 17 determines that the path is not a straight path.

In this manner, the straight line detection unit 17 searches for the end point of the path that continues from the start point by performing pixel search from the target pixel (i, j) that is the start point pixel. The end point search by the straight line detection unit 17 will be described in detail with reference to FIG.
FIG. 7 is an explanatory diagram of an example of path search.
FIGS. 7A and 7B show examples of searching for paths from the start point to the end point in binary image data, respectively.

  The straight line detection unit 17 sets an axis perpendicular to the search direction of the path from the start point in the binary image data. In the binary image data shown in FIGS. 7A and 7B, the path search direction from the start point is downward. In this case, the straight line detection unit 17 sets a rightward axis. For example, when the path search direction is the main scanning direction, the straight line detection unit 17 sets the axis in the sub-scanning direction.

Subsequently, the straight line detection unit 17 performs a pixel search to search for a path, and acquires a path coordinate value indicating the position of the path with respect to the set axis.
If the path coordinate value at the start point, that is, the start point coordinate value is k, the straight line detection unit 17 acquires the path coordinate value k + 1 when the pixel advances in the positive direction of the axis on which the path is set. Further, when the pass advances one pixel in the negative direction of the axis, the pass coordinate value k−1 is acquired.

  For example, in FIG. 7A or FIG. 7B, when the path advances rightward by one pixel from the starting point, that is, the path turns 90 degrees counterclockwise from the search direction at the starting point and advances one pixel. In this case, the path coordinate value acquired by the straight line detection unit 17 is k + 1. Further, when the path advances one pixel to the left from the position of the starting point, that is, when the path turns 90 degrees clockwise from the search direction at the starting point and advances one pixel, the path coordinate value acquired by the straight line detection unit 17 Becomes k-1.

Here, a path search example shown in FIG. 7A will be described.
In the binary image data shown in FIG. 7A, the path 30 detected by the straight line detection unit 17 first advances two pixels downward from the start point 30a. At this time, the straight line detection unit 17 acquires the start point coordinate value k of the start point 30a as the path coordinate value.

  Next, pass 30 turns 90 degrees counterclockwise and advances one pixel to the right. At this time, the straight line detection unit 17 acquires k + 1 as the path coordinate value of the path 30. In this way, the path coordinate value first changed from the starting point coordinate value k, that is, the path coordinate value at the position where the path 30 is first bent is hereinafter referred to as a second path coordinate value. In the path 30 shown in FIG. 7A, the second path coordinate value is k + 1.

  When the second path coordinate value is k + 1, that is, when the direction in which the path 30 is first bent is a counterclockwise direction as shown in FIG. At the search position where the coordinate value reaches k + 2 or k−1, the search for the path 30 is terminated. In FIG. 7A, the straight line detection unit 17 ends the pixel search when the path 30 reaches the search position 30b where the path coordinate value k−1. Then, the straight line detection unit 17 detects the search position immediately before the search position 30b as the end point 30c of the straight line path, and detects the path 30 from the start point 30a to the end point 30c as a straight line path. The path coordinate value of the detected end point 30c of the straight line path, that is, the end point coordinate value is k.

Similarly, a path search example shown in FIG. 7B will be described.
In the binary image data shown in FIG. 7B, the path 31 detected by the straight line detection unit 17 first advances two pixels downward from the starting point 30a, then turns clockwise by 90 degrees, and turns leftward. Advance one pixel. At this time, the straight line detection unit 17 acquires k−1 as the second path coordinate value of the path 31.

  When the second path coordinate value is k−1, that is, when the direction in which the path 31 is first bent is the clockwise direction as shown in FIG. At the search position where the path coordinate value reaches k + 1 or k-2, the search for the path 31 is terminated. In FIG. 7B, when the path 31 reaches the search position 31b where the path 31 becomes the path coordinate value k-2, the line search unit 17 ends the pixel search. The straight line detection unit 17 detects the path 31 from the start point 31a to the end point 31c as a straight line path, with the search position immediately before the search position 31b as the end point 31c of the straight line path 31. The end point coordinate value of the detected straight path is k-1.

  As described above, when the path search is completed and the end point of the straight line path is detected (step S106), the specifying unit 18 determines the deterioration pixel based on the detected straight line path based on the instruction from the straight line detection unit 17. Identification is performed (step S107).

Here, the specifying process of the deteriorated pixel by the specifying unit 18 will be described with reference to FIGS.
FIG. 8 is a flowchart showing the deteriorated pixel specifying operation of the copying apparatus according to the present invention, and FIG. 9 is an explanatory diagram showing an example of specifying the deteriorated pixel.

  In the copying apparatus 10, the specifying unit 18 first determines whether or not the straight line path detected by the straight line detecting unit 17 has distortion due to image degradation.

  When the straight line path is displaced only in the same direction with respect to the axis set by the straight line detection unit 17, that is, the specifying unit 18 determines that the path coordinate value of the straight line path is a value other than the start point coordinate value and the end point coordinate value. If the end point is reached without returning from the end point coordinate value to the start point coordinate value, it is determined that the straight line path is an oblique line path and there is no distortion due to image degradation (step S201). Then, the specifying unit 18 excludes the oblique line path from the target for specifying the deteriorated pixel (step S208).

  For example, in the binary image data shown in FIG. 9C, the path coordinate value of the straight path 32 changes from the start point coordinate value k of the start point 32a to the second path coordinate value k-1, and then to the end point 32c. The same path coordinate value is held, and the end point coordinate value is k-1. The specifying unit 18 determines that the straight line path 32 is an oblique line path (step S201), and excludes it from the target for specifying deteriorated pixels (step S208).

  Further, when the length from the start point to the end point of the straight line path, that is, the path length is less than the preset length threshold (step S202), the specifying unit 18 excludes the straight line path from the target for specifying the deteriorated pixel. (Step S208).

  If the straight path is not an oblique line path and the path length is equal to or longer than the length threshold, the specifying unit 18 determines that the straight path has distortion due to image deterioration (step S203), and specifies a deteriorated pixel. .

  In the binary image data, the specifying unit 18 sets each pixel that is in contact with the straight line path and located between the start point coordinate value and the end point coordinate value as a target pixel for determining whether or not it is a deteriorated pixel. In the binary image data shown in FIGS. 9A and 9B, each pixel in the hatched area is a specific target pixel.

  The identifying unit 18 regards each pixel near the start point and near the end point of the straight path among these target pixels as a straight corner and excludes it from the deteriorated pixels. Then, the specifying unit 18 specifies each pixel in a portion where the boundary between the white area and the black area between the start point and the end point is ambiguous as a deteriorated pixel.

  First, the specifying unit 18 specifies the start position of the deteriorated pixel. The specifying unit 18 specifies the position where the straight path is first bent, that is, the position where the path coordinate value has changed from the start point coordinate value to the second path coordinate value as the start position (step S204).

  In the binary image data shown in FIG. 9A, the specifying unit 18 specifies a position 33 d first bent from the start point 33 a as a start position based on the straight path 33. In the binary image data shown in FIG. 9B, the specifying unit 18 specifies a position 34 d first bent from the start point 34 a as the start position based on the straight path 34.

  Next, the specifying unit 18 specifies the end position of the deteriorated pixel. The specifying unit 18 specifies the position at which the straight path is finally bent, that is, the position at which the path coordinate value is finally changed to the end point coordinate value as the end position (step S205).

  In the binary image data shown in FIG. 9A, the specifying unit 18 specifies a position 33 e that is bent last toward the end point 33 c as an end position based on the straight path 33. Further, in the binary image data shown in FIG. 9B, the specifying unit 18 specifies a position 34e bent last toward the end point 34c as an end position based on the straight path 34.

  When the start position and the end position are specified, the specifying unit 18 specifies each target pixel between the start position and the end position as a deteriorated pixel, and counts the number of deteriorated pixels n ′ (step S206). The identifying unit 18 identifies each hatched hatched pixel as a degraded pixel in the straight path 33 shown in FIG. 9A, and counts the number of degraded pixels n ′ = 3. Further, the specifying unit 18 specifies each pixel hatched with diagonal lines as a deteriorated pixel in the linear path 34 shown in FIG. 9B, and counts the number of deteriorated pixels n ′ = 2.

  Then, the specifying unit 18 adds the counted number of deteriorated pixels n ′ to the number of deteriorated pixels n stored in the pixel number storage unit 19 and rewrites n = n + n ′ (step S207). Thereby, the deteriorated pixel specifying process by the specifying unit 18 ends.

  As described above, based on the straight line path detected by the straight line detection unit 17, the deteriorated pixels are specified, and the number of deteriorated pixels is counted.

  Returning to the detection specifying process in FIG. 4, when the deteriorated pixel is specified by the specifying unit 18 (step S <b> 107), the detection of the linear path for the target pixel (i, j) and the specified process of the deteriorated pixel are finished. The straight line detection unit 17 determines whether or not the target pixel (i, j) is the last pixel in the binary image data (step S108).

  If it is determined that the pixel is not the final pixel (step S108), the straight line detection unit 17 sets the next pixel in the binary image data, for example, the pixel (i, j + 1) as the pixel of interest, and performs the processing from step S102 onward Process.

  If it is determined that the target pixel (i, j) is the final pixel (step S108), the copying apparatus 10 ends the detection specifying process.

  If it is determined in step S103 that the pixel of interest (i, j) is not the start pixel, or if it is determined in step S105 that the path being searched is a non-linear path, the straight line detector 17 Determines whether or not the target pixel (i, j) is the last pixel (step S108). If it is not the last pixel, the copying apparatus 10 performs the processing from step S103 on for the next pixel. If it is the last pixel, the copying apparatus 10 ends the detection specifying process.

  As described above, after the image data is converted into binary image data, a linear path search process is executed for all the pixels included in the binary image data, and the number of deteriorated pixels included in the image data is determined. Counted.

Next, a flow in which the copying apparatus 10 executes a document copying process will be described with reference to the flowcharts shown in FIGS. 10 and 11 and FIG.
FIG. 10 is a flowchart (part 1) showing the copying operation in the first embodiment of the copying apparatus according to the present invention, and FIG. 11 is a flowchart (part 2) showing the copying operation in the first embodiment of the copying apparatus according to the present invention. ). FIG. 12 is an explanatory diagram showing an example of readability.

First, the case where 50% reduction of the original image shown in FIG.
FIG. 12A shows a document image before reduction, and FIG. 12B is a 50% reduced image of the document image shown in FIG.

  When the operator places an original on the placement table of the reading unit 11 and then operates the input device of the operator panel unit 12 to give a copy instruction for the original, the operator panel unit 12 inputs a copy request (step) S301).

  Based on the input of the copy request, the reading unit 11 reads an image of the document to generate image data, and stores the image data in the image data storage unit 14 (step S302).

  When the reduction of the document is designated (step S303), that is, when magnification information indicating the reduction magnification has been input by the operator panel unit 12, the operator panel unit 12 sends the image data storage unit 14 to the straight line detection unit 17. The detection of a straight line path from the stored image data is instructed. Here, it is assumed that the operator panel unit 12 has already input 50% as magnification information.

Line detection unit 17 receives the detection indication from the operator panel section 12, firstly, it initializes the total number of pixels n ₀ and degradation pixel number n stored in the pixel number memory unit 19 (step S304). The pixel number storage unit 19 stores the total number of pixels n ₀ = 0 and the number of deteriorated pixels n = 0.

  Then, the straight line detection unit 17 executes the straight line path detection process and the deteriorated pixel specification process (FIG. 4) together with the specifying unit 18 (step S305).

In the original image shown in FIG. 12A, each pixel in the hatched area is a deteriorated pixel specified by the specifying unit 18. The pixel number storage unit 19 stores the total number of pixels n ₀ = 63 and the number of deteriorated pixels n = 6 counted by the straight line detection unit 17 and the specifying unit 18 (step S305).

When the detection specifying process ends, the calculation unit 20 reads the total pixel number n ₀ and the deteriorated pixel number n from the pixel number storage unit 19, calculates the ratio value r based on the calculation formula r = n / n ₀ , It outputs to the readability determination part 21 (step S306). The calculation unit 20 calculates the ratio value r = 0.095 based on the total number of pixels n ₀ = 63 and the number of deteriorated pixels n = 6, and outputs it to the readability determination unit 21 (step S306).

Then, the readability determination unit 21 compares the ratio value r input from the calculation unit 20 with the ratio threshold value r _th to determine the magnitude (step S307). When the ratio value r is larger than the ratio threshold value r _th , the readability determination unit 21 determines that the readability of the reduced image of the document is low, that is, not readable (step S308).

  When the character “E” included in the document image shown in FIG. 12A is printed in a reduced size, it becomes indecipherable like the reduced image shown in FIG.

  Subsequently, the readability determination unit 21 instructs the operator panel unit 12 to display a warning screen.

  The operator panel unit 12 displays a warning screen (FIG. 3) on the display device in order to warn the operator of the low readability of the reduced image (step S309).

  As shown in FIG. 3, a message for warning the low readability of the reduced image is displayed on the warning screen. If the operator operates the input device of the operator panel unit 12 to select the execution of reduction copying while the warning screen (FIG. 3) is displayed, the operator panel unit 12 inputs an execution stop request (step S310). ).

  When the execution stop request is input (step S310), the copying process in the copying apparatus 10 ends.

  As described above, the readability of the reduced image is determined prior to the execution of the reduced copy process. If it is determined that the readability is low, a warning screen is displayed, and it is possible to select to cancel the execution of the reduced copy process.

  When the operator operates the input device of the operator panel unit 12 to select the forced execution of the reduced copy while the warning screen (FIG. 3) is being displayed (step S309), the operator panel unit 12 issues a forced execution request. Input (step S311).

  When the forced execution request is input (step S311), the reduction unit 15 reads the image data from the image data storage unit 14, and reduces the image based on the magnification information 50% input from the operator panel unit 12. The reduced image data is generated (step S312). The reducing unit 15 outputs the reduced image data as printing image data to the printing unit 13 (step S312).

  Then, the printing unit 13 performs printing based on the input printing image data (step S313). Thereby, the copying process in the copying apparatus 10 is completed.

Next, an example in which the original image shown in FIG. 12C is reduced by 50% will be described.
FIG. 12C shows a document image before reduction, and FIG. 12D is a 50% reduced image of the document image shown in FIG.

  When the operator panel unit 12 inputs a copy request (step S301), the reading unit 11 reads an image of a document to generate image data, and stores the image data in the image data storage unit 14 (step S302).

  When document reduction is specified (step S303), after the pixel number storage unit 19 is initialized (step S304), the straight line detection unit 17 and the specifying unit 18 detect straight line paths and specify deteriorated pixels. Processing (FIG. 4) is executed (step S305).

In the original image shown in FIG. 12C, each pixel in the hatched area is a deteriorated pixel specified by the specifying unit 18. The pixel number storage unit 19 stores the total number of pixels n ₀ = 252 and the number of deteriorated pixels n = 2 counted by the straight line detection unit 17 and the specifying unit 18 (step S305).

When the detection specifying process is completed, the calculation unit 20 reads out the total number of pixels n ₀ = 252 and the number of deteriorated pixels n = 2 from the pixel number storage unit 19, and calculates the ratio value r based on the calculation formula r = n / n _0. = 0.008 is calculated and output to the readability determination unit 21 (step S306).

Then, the readability determination unit 21 compares the ratio value r input from the calculation unit 20 with the ratio threshold value r _th to determine the magnitude (step S307). When the ratio value r is equal to or less than the ratio threshold value r _th , the readability determination unit 21 determines that the reduced image of the document is readable (step S314), and instructs the reduction unit 15 to reduce the image.

  The reduction unit 15 reads out the image data from the image data storage unit 14, reduces the image based on the magnification information 50%, generates reduced image data, and uses the reduced image data as print image data. The data is output to the printing unit 13 (step S312).

  The printing unit 13 performs printing based on the input printing image data (step S313). Thereby, the copying process in the copying apparatus 10 is completed.

  As described above, when it is determined that the reduced image is readable, the reduced copy process is executed.

  If it is determined in step S303 that the document reduction is not designated, the image data stored in the image data storage unit 14 is output to the printing unit 13 as image data for printing (step S315). ). The printing unit 13 performs printing based on the printing image data (step S313).

  As described above, the copying apparatus according to the present exemplary embodiment identifies the deteriorated pixels included in the image data, and determines the readability of the image after reduction based on the ratio value of the number of deteriorated pixels with respect to the total number of pixels. Therefore, when it is determined that the readability is low, the operator can be notified of the low readability by displaying a warning screen, so that the operator can avoid useless output.

FIG. 13 is a block diagram illustrating a functional configuration of the copying apparatus according to the second embodiment of the present invention.
The copying apparatus 40 of this embodiment is different from that of the first embodiment in the configuration in which an image area separation unit 41 is added.
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 13, the copying apparatus 40 according to the present embodiment includes a reading unit 11, an image data storage unit 43, a reduction unit 15, a printing unit 13, an image area separation unit 41, and binarization processing. A unit 42, a straight line detection unit 17, a specification unit 18, a pixel number storage unit 19, a calculation unit 20, a readability determination unit 21, and an operator panel unit 12 are configured.

  The image data storage unit 43 includes a storage device such as a hard disk or a RAM, and stores image data, binary image data, area image data to be described later, and the like.

  As the separation unit, the image region separation unit 41 separates the image data stored in the image data storage unit 43 into region image data of a character region including a character image and region image data of an image region such as a photograph. It has a function. For example, the image area separation unit 41 analyzes a block of 3 × 3 pixels around the pixel of interest, and if the change rate of the pixel density value or the saturation value in the block is large, the pixel of interest is a feature point. Then, the image area separation unit 41 separates the character area from the image area by tracking other feature points in the vicinity of the feature point. The image area separation unit 41 causes the image data storage unit 43 to store the area image data of the character area among the separated area image data.

FIG. 14 is an explanatory diagram showing an example of image area separation.
The image area separation unit 41 separates the character areas 44-1 and 44-3 and the image area 44-2 from the document image 44. Then, the area image data of the character areas 44-1 and 44-3 is acquired and output to the binarization processing unit 42.

  The binarization processing unit 42 reads out the region image data from the image data storage unit 43, performs binarization processing on the region image data, and stores the binary image data in the image data storage unit 43.

Next, the operation of the copying apparatus 40 of this embodiment will be described.
Here, a flow in which the copying apparatus 40 executes a document copying process will be described with reference to flowcharts shown in FIGS. 15 and 16.
FIG. 15 is a flowchart (No. 1) showing a copying operation in the second embodiment of the copying apparatus according to the present invention. FIG. 16 is a flowchart (No. 2) showing a copying operation in the second embodiment of the copying apparatus according to the present invention. ).

  When the operator places an original on the placement table of the reading unit 11 and then operates the input device of the operator panel unit 12 to give a copy instruction for the original, the operator panel unit 12 inputs a copy request (step) S301).

  Based on the input of the copy request, the reading unit 11 reads an image of the document to generate image data, and stores the image data in the image data storage unit 43 (step S302).

  When the document reduction is designated (step S303), the operator panel unit 12 instructs the straight line detection unit 17 to detect a straight path from the image data stored in the image data storage unit 43.

Line detection unit 17 receives the detection indication from the operator panel section 12, firstly, it initializes the total number of pixels n ₀ and degradation pixel number n stored in the pixel number memory unit 19 (step S304).

  Subsequently, the straight line detection unit 17 instructs the image region separation unit 41 to perform image region separation. Based on this image area separation instruction, the image area separation unit 41 reads the image data from the image data storage unit 43, separates the area image data of the character area from the image data, and stores the area image data in the image data storage The data is stored in the unit 43 (step S401).

  Then, along with the specifying unit 18, the straight line detecting unit 17 executes a straight line detection process and a deteriorated pixel specifying process (FIG. 4) on the area image data stored in the image data storage unit 43 (step 4). S402).

The detection specifying process by the straight line detection unit 17 and the special case unit 18 is executed for each area image data. The pixel number storage unit 19, the total number of pixels n ₀ of the area image data, and the number of degraded pixels n in each area image data is stored is sequentially added (step S402).

The region image data corresponding to all the character area, the read detection identification process is completed (step S403), calculation unit 20, and a number of degradation pixels to the total pixel number n ₀ n from the pixel number storage section 19 Then, the ratio value r is calculated based on the calculation formula r = n / n ₀ and is output to the readability determination unit 21 (step S306).

Then, the readability determination unit 21 compares the ratio value r input from the calculation unit 20 with the ratio threshold value r _th to determine the magnitude (step S307). Since the flow after step S307 is the same as that in the first embodiment, a description thereof will be omitted.

  As described above, the area image data of each character area is separated from the image data, and after the linear path detection process and the deteriorated pixel identification process are performed on the area image data, the ratio value r is calculated. The

  As described above, the copying apparatus according to the present embodiment performs readability determination based on the area image data of the character area. In addition to the effects of the first embodiment, the copying apparatus further includes an image that is extremely different from the character image. Accurate readability can also be determined for image data.

FIG. 17 is a block diagram illustrating a functional configuration of the copying apparatus according to the third embodiment of the present invention.
The copying apparatus 60 according to the present embodiment is different from the first and second embodiments in that the layout unit 61 is added.
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  As shown in FIG. 17, the copying apparatus 60 according to the present exemplary embodiment is a reading unit 62, an image data storage unit 63, a reduction unit 64, a layout unit 61, a printing unit 13, and a binarization processing unit 16. , A straight line detection unit 17, a specification unit 18, a pixel number storage unit 19, a calculation unit 20, a readability determination unit 21, and an operator panel unit 65.

  The reading unit 62 reads a plurality of documents as an input unit, inputs image data as a plurality of original image data, and stores the image data in the image data storage unit 63.

  The image data storage unit 63 includes a storage device such as a hard disk or a RAM, and stores a plurality of image data and binary image data.

  The reduction unit 64 serves as a reduced layout unit based on layout information N (described later) input from the operator panel unit 65 and a plurality of pieces of reduced image data based on a plurality of pieces of image data stored in the image data storage unit 63. And the reduced image data is output to the layout unit 61.

  The layout unit 61 lays out each reduced image data input from the reduction unit 64 as a reduced layout unit, generates one print image data, and outputs the image data to the printing unit 13.

  The operator panel unit 65 inputs a numerical value N as layout information for instructing N-Up printing. Here, N-UP printing means printing performed by laying out N documents on one output sheet.

FIG. 18 is an explanatory diagram illustrating a reduced layout example of 4-Up printing.
FIG. 18A shows four original images read from four originals, and FIG. 18B shows a reduced layout image for one page generated by reducing these original images. is there.

  When 4-Up printing is executed, the reduction unit 64 reduces the original images for four pages, and outputs four reduced image data to the layout unit 61. The layout unit 61 displays the reduced image data of the first page of the document on the upper left, the reduced image data of the second page of the document on the upper right, the reduced image data of the third page of the document on the lower left, and The reduced image data is laid out at the lower right, and print image data for the reduced layout image shown in FIG. 18B is generated. Based on this print image data, the reduced layout image is printed on one output sheet, whereby 4-Up printing is executed.

In addition, the operator panel unit 65 displays a warning screen for warning the low readability of the reduced layout image on the display device as a notification unit.
FIG. 19 is an explanatory diagram illustrating a display example of a warning screen according to the third embodiment.

  Further, the operator panel unit 65 inputs a forced execution request for requesting forced execution of layout printing and an execution stop request for requesting stop of layout printing. Further, the operator panel unit 65 inputs a re-layout request for requesting a re-layout together with the layout information N as a changing unit.

Next, the operation of the copying apparatus 60 of this embodiment will be described.
Here, a flow in which the copying apparatus 60 executes a document copying process will be described with reference to flowcharts shown in FIGS.
FIG. 20 is a flowchart (No. 1) showing a copying operation in Embodiment 3 of the copying apparatus according to the present invention. FIG. 21 is a flowchart (No. 2) showing a copying operation in Embodiment 3 of the copying apparatus according to the present invention. ).

  After the operator places a plurality of documents on the reading unit 62 and operates the input device of the operator panel unit 65 to give a copy instruction for the document, the operator panel unit 65 inputs a copy request (step) S501).

  Based on the input of the copy request, the reading unit 62 sequentially reads the image of each document, generates a plurality of image data, and stores each image data in the image data storage unit 63 (step S502).

  When N-Up printing of a document is designated (step S503), that is, when layout information N has been input by the operator panel unit 65, the operator panel unit 65 sets the layout information N and also detects a straight line detection unit. 17, the detection of a straight path from the image data stored in the image data storage unit 63 is instructed. Here, it is assumed that the operator panel unit 65 has already input N = 4 as the layout information.

Line detection unit 17 receives the detection indication from the operator panel section 65, firstly, it initializes the total number of pixels n ₀ and degradation pixel number n stored in the pixel number memory unit 19 (step S304).

  Then, the straight line detection unit 17 executes, together with the specifying unit 18, a straight path detection process and a deteriorated pixel specifying process (FIG. 4) for each image data (step S <b> 504).

The detection specifying process by the straight line detection unit 17 and the specifying unit 18 is performed for each image data. The total number of pixels n ₀ and the number of deteriorated pixels n of each image data are added and stored in the pixel number storage unit 19 (step S504).

For each image data corresponding to the N sheets of the document, and detecting the specific process ends (step S505), calculation unit 20, the and the deterioration number of pixels n the total number of pixels n ₀ from the pixel number storage section 19 Read, calculate the ratio value r based on the calculation formula r = n / n ₀ , and output it to the readability determination unit 21 (step S306).

The readability determination unit 21 compares the ratio value r input from the calculation unit 20 with the ratio threshold value r _th to determine the size (step S307). When the ratio value r is larger than the ratio threshold value r _th , the readability determination unit 21 determines that the readability of the reduced image of the document is low, that is, is not readable (step S308), and instructs the operator panel unit 65 to display a warning screen. To do.

  The operator panel unit 65 displays a warning screen (FIG. 19) on the display device in order to warn the operator of the low readability of the reduced layout image (step S506).

  The warning screen shown in FIG. 19 displays a message for warning the low readability of the 4-Up reduced layout image. If the operator depresses the 2 button on the numeric keypad of the operator panel unit 65 while the warning screen is displayed, the operator panel unit 65 inputs a re-layout request and N = 2 as layout information (step S507). .

  Based on the re-layout request and the layout information input, the operator panel unit 65 resets the layout information N (step S508), and instructs the straight line detection unit 17 to detect a straight line path. Then, the straight line detection unit 17 initializes the pixel number storage unit 19 (step S304), and for the two image data corresponding to the two originals, a straight line detection process and a deteriorated pixel identification process (see FIG. 4) is executed (step S504).

When the detection specifying process for each image data is completed (step S505), the ratio value r is calculated by the calculation unit 20 (step S306), and the readability determination unit 21 compares the ratio value r with the ratio threshold value r _th again. (Step S307).

When the ratio value r is equal to or less than the ratio threshold r _th (step S307), the readability determination unit 21 determines that the reduced layout image is readable (step S314), and instructs the reduction unit 64 to reduce the document.

  Then, the reduction unit 64 reads the two image data from the image data storage unit 63, reduces each image based on the reduction magnification corresponding to 2-Up printing, and generates two reduced image data (step). S509). The reduction unit 64 outputs each generated reduced image data to the layout unit 61 (step S509).

  When two pieces of reduced image data are input, the layout unit 61 lays down the reduced image data corresponding to the first original on the left and the reduced image data corresponding to the second original on the right, and prints it. Image data is generated (step S510). Then, the layout unit 61 outputs the printing image data to the printing unit 13 (step S510).

  The printing unit 13 performs printing based on the input printing image data (step S313). When there is unprinted image data in the image data storage unit 63 (step S511), the copying apparatus 60 executes the processing from step S503 on these image data. If there is no unprinted image data (step S511), the copying process in the copying apparatus 60 ends.

  As described above, after it is determined that the reduced layout image is not readable, when a re-layout is requested on the warning screen, layout information smaller than the set layout information is reset. Then, the readability determination is performed again based on the layout information.

  When an execution stop request is input by the operator panel unit 65 (step S309) while the warning screen (FIG. 19) is being displayed (step S506), the copying apparatus 60 ends the copying process.

  Further, when a forced execution request is input from the operator panel unit 65 (step S310) while the warning screen (FIG. 19) is being displayed (step S506), the reduction unit 64 receives four image data from the image data storage unit 63. Are reduced, each image is reduced based on the reduction ratio corresponding to 4-Up printing, four pieces of reduced image data are generated, and output to the layout unit 61 (step S509).

  The layout unit 61 lays out the input four pieces of reduced image data as shown in FIG. 18 to generate print image data (step S510). Then, the layout unit 61 outputs the printing image data to the printing unit 13 (step S510).

  The printing unit 13 performs printing based on the input printing image data (step S313). When there is unprinted image data in the image data storage unit 63 (step S511), the copying apparatus 60 executes the processing after step S503. If there is no unprinted image data (step S511), the copying process in the copying apparatus 60 ends.

  If it is determined in step S503 that N-Up printing is not designated, each image data stored in the image data storage unit 63 is output to the printing unit 13 as image data for printing ( Step S512). The printing unit 13 performs printing based on the printing image data (step S313).

  As described above, the copying apparatus according to the present embodiment can determine the readability of the reduced layout image during N-Up printing, and can continue printing by resetting the layout information N. Be improved.

  In the copying apparatus according to the present exemplary embodiment, when it is determined that the reduced layout image is not readable, a warning screen is displayed to allow the operator to select any one of re-layout, forced printing, and print cancellation. Is not limited to this. By setting the re-layout in advance, it is possible to continue the printing by re-laying out without displaying the warning screen.

  In each of the embodiments described above, the copying apparatus has been described as an example of the image processing apparatus according to the present invention, but the present invention is not limited to this. The present invention can also be applied to an image forming apparatus including a printer unit and a FAX unit, a personal computer, a workstation, and the like.

1 is a block diagram showing a functional configuration of a copying apparatus according to Embodiment 1 of the present invention. 1 is an external view of a copying apparatus according to the present invention. FIG. 10 is an explanatory diagram illustrating a display example of a warning screen in the first embodiment. 5 is a flowchart showing a detection specifying operation of the copying apparatus according to the present invention. It is explanatory drawing which shows a starting point pattern. It is explanatory drawing which shows an exclusion pattern. It is explanatory drawing which shows the example of a search of a path | pass. 5 is a flowchart showing a deteriorated pixel specifying operation of the copying apparatus according to the present invention. It is explanatory drawing which shows the specific example of a degradation pixel. 5 is a flowchart (part 1) illustrating a copying operation in the first embodiment of the copying apparatus according to the present invention. 6 is a flowchart (No. 2) showing a copying operation in Embodiment 1 of the copying apparatus according to the present invention. It is explanatory drawing which shows the example of readability. FIG. 6 is a block diagram illustrating a functional configuration of a copying apparatus according to a second embodiment of the invention. It is explanatory drawing which shows the example of image area separation. 6 is a flowchart (part 1) showing a copying operation in Embodiment 2 of the copying apparatus according to the present invention. 6 is a flowchart (No. 2) showing a copying operation in Embodiment 2 of the copying apparatus according to the present invention. It is a block diagram which shows the function structure of the copying apparatus which concerns on Example 3 of this invention. It is explanatory drawing which shows the reduction layout example of 4-Up printing. FIG. 10 is an explanatory diagram illustrating a display example of a warning screen in the third embodiment. 6 is a flowchart (part 1) showing a copying operation in Embodiment 3 of the copying apparatus according to the present invention. 12 is a flowchart (part 2) showing a copying operation in Embodiment 3 of the copying apparatus according to the present invention.

Explanation of symbols

10, 40, 60 Copier 11, 62 Reading unit 12, 65 Operator panel unit 13 Printing unit 14, 43, 63 Image data storage unit 15, 64 Reduction unit 16, 42 Binarization processing unit 17 Linear detection unit 18 Identification unit 19 pixel number storage unit 20 calculation unit 21 readability determination unit 41 image area separation unit 61 layout unit

Claims (9)

An input unit that inputs original image data of an original image, and a reduced output unit that generates and outputs reduced image data of a reduced image obtained by reducing the original image based on the input original image data In the image processing apparatus provided,
A detection unit for detecting a straight path in the input original image data;
A specifying unit for specifying a specific pixel included in the original image data based on the detected straight line path;
A calculation unit that calculates a ratio value indicating a ratio of the specific pixel number to the total pixel number based on the total pixel number of the original pixel data and the specific pixel number of the specified specific pixel;
A determination unit that determines the readability of the reduced image data based on the calculated ratio value;
When it is determined that it is not readable, a notification unit that notifies the determination result;
An image processing apparatus comprising:   The image processing apparatus according to claim 1, further comprising a request unit that requests cancellation of the output by the reduced output unit.   The image processing apparatus according to claim 1, wherein the input unit includes a reading unit that reads an image of a document and acquires original image data.   The image processing apparatus according to claim 1, wherein the specifying unit performs the specifying operation when a length of the straight path detected by the detecting unit is equal to or greater than a predetermined threshold. The input unit inputs binary data indicating either a black pixel or a white pixel,
In the input binary data, the detection unit performs a pixel search along a boundary between a black region composed of black pixels and a white region composed of white pixels, and detects the linear path. The image processing apparatus according to claim 1. A separation unit that separates the region image data of the character region from the input image data;
The detection unit detects a straight path in the separated region image data,
The image according to claim 1, wherein the calculation unit calculates the ratio value based on the number of pixels of the region image data and the specific number of pixels of the specific pixel specified by the specifying unit. Processing equipment. In order to output a plurality of original images to one medium, the image processing apparatus further includes a reduction layout unit for reducing and laying out the original images based on a reduction ratio,
The input unit inputs a plurality of original image data,
The detection unit detects the straight path in the plurality of input original image data;
The calculation unit calculates the ratio value based on the total number of pixels of the plurality of original image data and the specific pixel number of the specific pixel specified by the specifying unit,
The image processing apparatus according to claim 1, wherein the determination unit determines readability of a reduced layout image in which the plurality of original images are reduced and laid out based on the calculated ratio value. When it is determined that the determination unit is not readable, it further includes a changing unit that changes the reduction ratio,
The image processing apparatus according to claim 7, wherein the reduced layout unit performs reduction and layout of the original image based on the changed reduction magnification.   The image processing apparatus according to claim 7, wherein the input unit includes a reading unit that reads images of a plurality of documents and acquires a plurality of original image data.

Images