JP2012098811A - Image processing apparatus, image forming apparatus, image processing control device, image processing control method, computer program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus, image forming apparatus, image processing control device, image processing control method, computer program and recording medium in which the labor for a user to distinguish between a color document and a monochromatic document can be saved compatibly with preventing reduction in OCR precision from the monochromatic document.SOLUTION: An image processing apparatus which has a dropout color processing section which performs dropout color processing prior to character recognition processing includes a color determination section which determines whether input image data are image data produced by being read from a color document or a monochromatic document, and a control section which executes character recognition processing without performing dropout color processing on image data relating to the input image data in the case where the color determination section determines that the input image data are image data produced by being read from the monochromatic document.

Description

  The present invention relates to an image processing apparatus, an image forming apparatus, an image processing control apparatus, an image processing control method, a computer program, and a recording medium that perform character recognition of image data generated by reading a document.

  Conventionally, dropout color processing is sometimes performed in an image processing apparatus that optically reads and processes an image, such as a digital color copying machine, a multifunction peripheral, and a document scanner. The purpose of the dropout color processing is to improve the accuracy of character recognition in OCR (Optical Character Recognition). Specifically, an area having a specific hue (dropout color) that causes a reduction in the accuracy of character recognition, such as a color frame line, is erased, and only black characters necessary for character recognition are left (for example, Patent Document 1). .

  In addition, there is an image processing apparatus that performs different image processing based on a result of determining whether image data is obtained by reading a color document or image data obtained by reading a monochrome document. In such an apparatus, it is possible to save the user from inputting information on whether the document is color or monochrome, and further according to the characteristics of the image data based on whether the document is color or monochrome. Image processing can be executed.

  By the way, when the output image data is monochrome, there is an image processing apparatus that is always set to execute dropout color processing. This is because the dropout color process aims at improving the accuracy of character recognition for reading black characters such as handwritten characters.

Japanese Patent Laid-Open No. 10-27213 Japanese Patent Laid-Open No. 2002-232708 JP-A-4-282968

  However, when dropout color processing is performed on image data obtained by reading a monochrome document, a black character edge may be determined as a dropout color target area when color misregistration occurs. As a result, the black character edge is removed, and deterioration such as thinning of the character or fading of the character occurs. This is a factor that decreases the accuracy of character recognition.

  The present invention has been made in view of such circumstances, and an image processing apparatus that allows the user to save time and effort to distinguish between a color original and a monochrome original and does not reduce the OCR accuracy from the monochrome original. An object of the present invention is to provide an image forming apparatus, an image processing control apparatus, an image processing control method, a computer program, and a recording medium.

  An image processing apparatus according to the present invention includes an image processing apparatus having a dropout color processing unit that performs dropout color processing prior to character recognition processing, and generates input image data by reading from either a color document or a monochrome document. A color determination unit that determines whether the input image data is generated, and the color determination unit determines that the input image data is image data generated by reading from a monochrome document. And a control unit that determines to execute the character recognition process without executing the dropout color process for the image data.

  In the present invention, both the user's trouble of distinguishing between a color document and a monochrome document and the character recognition accuracy of image data read from the monochrome document are not reduced by the dropout color processing. Can be made.

  The image processing apparatus according to the present invention further includes a character determination unit that determines whether or not a character image is included in the input image data, and the control unit is configured such that the color determination unit and the input image data are When it is determined that the image is read and generated from a color document, and the character determination unit determines that a character image is included in the input image data, dropout color processing and image data related to the input image data It is characterized by determining to perform a character recognition process.

  In the present invention, the dropout color process and the character recognition process are performed when it is determined that a character image is included, so that the time required for the entire process can be reduced.

  The image processing apparatus according to the present invention further includes a character area specifying unit that specifies an area including a character image in the input image data, and the control unit includes the image data in the input image data. The character area specifying unit is configured to determine that the dropout color process and the character recognition process are to be performed on an area corresponding to the area specified by the character area specifying unit.

  In the present invention, the area for executing the dropout color processing can be reduced, so that the time required for the entire processing can be shortened.

  Further, the image processing apparatus according to the present invention determines that the input image data includes a background image, and a background determination unit that determines whether the input image data includes a background image, and the background determination unit. A background removal unit that performs background removal on the image data related to the input image data, and the control unit performs dropout color processing on the image data after the background removal unit removes the background And a character recognition process.

  In the present invention, the dropout color process can be executed while eliminating the influence of the background of the document.

  An image forming apparatus according to the present invention includes any one of the image processing apparatuses according to the present invention, and further performs image processing for forming an image of the image data on a medium with respect to the image data. The image processing apparatus includes: a processing unit; and an image forming unit that forms and outputs an image of image data on which the image processing unit has performed the image processing on a medium.

  In the present invention, it is possible to provide an image forming apparatus having the same effects as the image processing apparatus according to the present invention.

  In addition, the image processing control apparatus according to the present invention determines whether input image data is image data generated by reading from a color document or a monochrome document, and performs a drop performed prior to character recognition processing. An image processing control apparatus for executing a determination as to whether or not to execute out-color processing, wherein the input image data is determined when the input image data is determined to be image data generated by reading from a monochrome document. And a control unit that determines to perform character recognition processing without performing dropout color processing on the image data.

  The present invention provides an image processing control device that exhibits the same effects as the image processing device according to the present invention.

  An image processing control method according to the present invention is an image processing control method for selecting whether or not to perform dropout color processing prior to character recognition processing, wherein the image data includes color documents and monochrome documents. A step of determining from which image data is read and generated; and in the step, when it is determined that the image data is read and generated from a monochrome document, the image data related to the image data is And determining to execute the character recognition process without executing the dropout color process.

  The present invention provides an image processing control method that exhibits the same effects as the image processing apparatus according to the present invention.

  The computer program according to the present invention is a computer program for causing a computer to select whether or not to execute dropout color processing prior to character recognition processing. A color determination step for determining which image data is read and generated, and the input image data is determined to be image data generated by reading from a monochrome document in the color determination step. And a step of determining that character recognition processing is to be performed without performing dropout color processing on the image data related to the input image data.

  According to another aspect of the present invention, there is provided a computer program, wherein the input image data is obtained from a color original in the character determination step for determining whether or not the input image data includes a character image and the color determination step. If it is determined that the input image data includes a character image, and the character determination step determines that the input image data includes a character image, dropout color processing and characters are performed on the image data related to the input image data. And a step of determining to execute the recognition process.

  Further, the computer program according to the present invention specifies, in the computer, a character determination step for determining whether or not a character image is included in the input image data, and an area including the character image in the input image data. In the character region specifying step and the color determining step, it is determined that the input image data is read and generated from a color original, and in the character determining step, it is determined that the input image data includes a character image. Determining whether to perform dropout color processing and character recognition processing on an area corresponding to the area specified in the character area determination step in the image data related to the input image data. Furthermore, it is made to perform.

  The computer program according to the present invention has the same effects as the image processing apparatus according to the present invention.

  In addition, a recording medium according to the present invention records any one of the computer programs of the present invention.

  The recording medium according to the present invention has the same effects as the computer program according to the present invention.

  According to the present invention, an image processing apparatus, an image forming apparatus, and an image processing apparatus that can achieve both a user's trouble of distinguishing between a color document and a monochrome document and a reduction in OCR accuracy from a monochrome document. An image processing control apparatus, an image processing control method, a computer program, and a recording medium can be provided.

It is a figure explaining the image processing apparatus and peripheral apparatus which concern on this Embodiment. It is a figure explaining the detail of an image processing apparatus. 3 is a block diagram illustrating an example of a functional configuration of a document determination unit. FIG. It is a figure which shows the example of a histogram. It is a figure which shows the gradation correction curve of background removal. It is a block diagram which shows the function structure of a dropout color process part. It is a figure which shows a gamma correction table. It is a flowchart explaining the image processing method which concerns on this Embodiment. It is a figure which shows each part which processes, and the data format which each part outputs, when performing character recognition. It is a figure which shows each part which processes, and the data format which each part outputs, when not performing character recognition. It is a flowchart explaining dropout color processing. It is a flowchart explaining the process which adds text data to image data. FIG. 10 is a diagram illustrating an example of character recognition when dropout color processing is selected for an original composed only of monochrome pixels. It is a flowchart explaining the example from which the image processing method which concerns on this Embodiment differs. 10 is a flowchart illustrating details of document determination processing in step S203. It is a flowchart explaining the process which performs a dropout color process to the pixel which belongs to the area | region of a character image. It is a flowchart explaining the detail of the process which adds text data to the image data of the area | region of a character image. 2 is a diagram illustrating an example of a hardware configuration of an image forming apparatus according to the present embodiment. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, a color having a smaller luminance and density value is a darker (darker) color, and a color having a larger luminance and density value is a brighter (lighter) color.

  FIG. 1 is a diagram for explaining an image processing apparatus and peripheral apparatuses according to the present embodiment. 1 is connected to an image input device 5, an image output device 6, and a transmission / reception device 8.

  The image processing device 1 processes image data input from the image input device 5 and outputs the processed image data to the image output device 6 or the transmission / reception device 8. Details of the image processing apparatus 1 will be described later.

  For example, the image input device 5 optically reads a document and outputs image data. The image input device 5 has a line sensor (not shown) having a CCD (Charge Coupled Device). The line sensor outputs an electrical signal obtained by color-separating light reflected by the document into R (red), G (green), and B (blue), that is, a color image signal (RGB analog signal).

  The image output device 6 forms an output image from the image data output by the image processing device 1 and outputs the output image. The image data input to the image output device 6 is, for example, image data based on CMYK signals. The image output apparatus 6 is an apparatus (plotter) that forms an image on a medium, such as an electrophotographic printer or an inkjet printer.

  The transmission / reception device 8 transmits the image data output from the image output device 6 to an external device. The image data input from the image processing apparatus 1 to the transmission / reception apparatus 8 is, for example, image data in PDF format. The transmission / reception device 8 attaches image data in PDF format to an electronic mail and transmits it to another device via a network. The transmission / reception device 8 also receives image data or control signals from other devices.

FIG. 2 is a diagram for explaining the details of the image processing apparatus 1.
The image processing apparatus 1 includes an image processing unit 10, a storage unit 41, and a control unit 42. The image processing unit 10 converts the RGB analog signal input from the image input device 5 into a digital signal to generate input image data, performs various image processing, and transmits the processed image data to the image output device 6 or transmission / reception. Output to device 8. The image processing unit 10 also causes the storage unit 41 to store input image data or intermediate image data that is intermediately generated by image processing of the input image data.

  The storage unit 41 stores image data. The image data stored in the storage unit 41 is intermediate image data processed by the image processing unit 10. The image data stored in the storage unit 41 includes input image data obtained by converting RGB analog signals input from the image input device 5, image data before being output from the image processing unit 10 to the image output device 6, and Image data transmitted and received by the transmission / reception device 8 may be used.

  The storage unit 41 stores the image data after compressing it into a JPEG code based on, for example, a JPEG compression algorithm. The storage unit 41 may be configured as a hard disk device, for example.

  The control unit 42 performs control for storing image data in the storage unit 41, management of image data stored in the storage unit 41, and control of operations of each unit included in the image processing unit 10. The control unit 42 is configured as, for example, a CPU (Central Processing Unit) or a DSP (Digital Signal Processor).

  The image processing unit 10 includes an analog / digital conversion unit (hereinafter referred to as “A / D conversion unit”) 11, a shading correction unit 12, an input processing unit 13, a document determination unit 14, a background removal unit 15, and dropout color processing. 16, color correction unit 17, black generation / undercolor removal unit 18, spatial filter unit 19, output tone correction unit 20, halftone generation unit 21, region separation unit 22, character recognition unit 31, drawing command generation unit 32 And a formatting processor 33.

  The A / D converter 11 converts the RGB analog signal input from the image input device 5 into a digital signal. The shading correction unit 12 removes distortion included in the digital signal. The distortion to be removed is, for example, distortion generated in the illumination system, the imaging system, and the imaging system when the image input apparatus 5 optically reads a document. The input processing unit 13 performs γ correction on the digital signal.

  The image data processed by the shading correction unit 12 and the input processing unit 13 is referred to as input image data, and the image data after at least one or more image processing is performed on the input image data is an intermediate image. It is called data. The input image data and the intermediate image data are collectively referred to as processed image data. The input image data may be stored in the storage unit 41 after being converted into a JPEG code.

  The document determination unit 14 executes document determination processing for determining the characteristics of the read document from the input image data. The document determination unit 14 outputs the determination result as document determination data. The document determination process includes document type determination, background presence / absence determination, and color determination. FIG. 3 is a block diagram illustrating an example of a functional configuration of the document determination unit 14. The document determination unit 14 includes a document type determination unit 141, a background determination unit 143, and a color determination unit 145. The document determination unit 14 may not include the document type determination unit 141 and the background determination unit 143.

  The document type determination unit 141 determines the document type. More specifically, for example, it is determined whether or not the read document includes a character image. The document type determination unit 141 determines, for example, whether the type of the read document is a character document, a printed photo document, or a character printed photo document in which characters and a printed photo are mixed. The document type determination unit 141 determines the type of document using, for example, the method described in Patent Document 2. The following (1) to (7) are the outline of the method described in Patent Document 2.

(1) The minimum density value and the maximum density value in an n × m (for example, 7 × 15) block including the target pixel are calculated.
(2) The maximum density difference is calculated using the calculated minimum density value and maximum density value.
(3) The total density busyness (for example, the sum of values calculated in the main scanning direction and the sub-scanning direction), which is the sum of absolute values of density differences between adjacent pixels, is calculated.
(4) A comparison between the calculated maximum density difference and the maximum density difference threshold and a comparison between the calculated total density busyness and the total density busyness threshold are performed.
When the maximum density difference <the maximum density difference threshold and the total density busyness <the total density busyness threshold, it is determined that the target pixel belongs to the background / photographic paper photograph area.
When the above condition is not satisfied, it is determined that the target pixel belongs to the character / halftone dot region.

(5) About the pixel determined to belong to the background / photographic paper photograph area
When the maximum density difference <the background / photographic paper photograph determination threshold is satisfied, the pixel is determined to be a background pixel. When the above condition is not satisfied, the pixel is determined to be a photographic paper photograph (photo region, continuous tone region) pixel.

(6) Regarding the pixel determined to belong to the character / halftone dot region
When the condition of total density busyness <maximum density difference multiplied by a character / halftone dot determination threshold is satisfied, it is determined as a character pixel, and when the above condition is not satisfied, it is determined as a halftone pixel.

(7) Count the number of pixels classified into a background area, a photographic paper photograph area, a character area, and a halftone dot area, and count values and predetermined ground areas, a photographic paper photograph area, and a halftone dot area. The type of the entire document is determined by comparing with the threshold value for the character area. For example, assuming that the detection accuracy is higher in the order of characters, halftone dots, and photographic paper photographs, the ratio of the text original and halftone areas is 20% of the total number of pixels when the ratio of the character areas is 30% or more of the total number of pixels In the above case, when the ratio of the halftone original (printed photo original) and the photographic paper photo area is 10% or more of the total number of pixels, it is determined that the image is a photographic paper photo original. Further, when the ratio of the character area and the ratio of the halftone dot area are equal to or greater than the threshold value, respectively, it is determined that the character / halftone original (character-printed photo original).

  When determining the document type, the document type determination unit 141 may determine the document type by sampling pixels instead of targeting all the pixels. When identifying a pixel, the document type determination unit 141 may exclude a pixel having a feature amount near a threshold and select a pixel having a significant feature amount to determine the document type.

  The user may input the document type from an operation panel (not shown). Information on the document type input from the operation panel is acquired by the control unit 42.

The background determination unit 143 determines the background density of the read document. The background density is, for example, the color of original paper. The background determination unit 143 first acquires a luminance signal from data input as an RGB signal. For example, the following equation (1) is used to acquire the luminance signal.
Y _j = 0.30R _j + 0.59G _j + 0.11B _j (1)
Where Y _j : luminance signal of each pixel,
R _j , G _j , B _j : Color components of each pixel

Instead of the luminance signal, it is converted into a uniform color space such as CIE L ^* a ^* b ^* signal (CIE: Commission International de l'Eclairage: International Lighting Commission. L ^* : brightness, a ^* , b ^* : chromaticity) Then, the brightness signal may be obtained.

The background determination unit 143 creates a histogram of the entire image based on the obtained luminance signal or lightness signal. FIG. 4 is a diagram illustrating an example of a histogram. In histogram created, most frequent high frequency is regarded as the threshold value th1 or more luminance or lightness background portion, is compared with the threshold value th2 set in advance with the luminance or brightness Y _f in this case.

  The threshold th1 is the minimum value of the number of pixels determined to be the background. For example, the threshold value th1 may be set in association with the document size detection result by storing the document size and the minimum value of the number of pixels determined to be the background. The threshold th2 is an upper limit value of the density value determined as the background.

When Y _f ≦ th2, the background determination unit 143 determines that the background density (luminance or brightness) is below the threshold, that is, the background is detected. In other cases, the background determination unit 143 determines that the background is equal to or higher than a predetermined density (luminance or brightness), that is, no background.

  The background determination unit 143 also determines whether or not the read original is a plain original (blank original).

  Based on the determination result by the background determination unit 143, the background removal unit 15 performs background removal.

  The color determination unit 145 performs automatic color determination processing (hereinafter referred to as “ACS (Auto Color Selection)”) on the input image data. ACS is a process for determining whether image data read from a color original or image data read from a monochrome original.

  For example, the color determination unit 145 executes ACS when the color mode selected by the operator is “automatic”. As the color mode, for example, the operator selects one of full color, automatic, and black and white from the initial screen of the operation panel. The color determination unit 145 may also perform ACS on all input image data.

  For the ACS, for example, a method described in Patent Document 3 may be applied. According to the method described in Patent Document 3, it is determined whether each pixel is a color pixel or a monochrome pixel, and when the presence of a predetermined number or more of continuous color pixels is detected in the given pixel order, A continuous color pixel is recognized as a color block. If a predetermined number or more of color blocks exist in one line, the line is counted as a color line. If a predetermined number of color lines exist in the input image data read from one original, it is determined as a color original, and otherwise it is determined as a monochrome image.

  The number of continuous color pixels when determining whether or not a color block and the predetermined number of color lines when determining as a color document may be appropriately set based on the criterion for determining as a color document. The standard for determining a color document is, for example, the number or ratio of color pixels included in the document. The standard for determining a color document may be set in advance.

In the above method, for determining whether each pixel is a color pixel or a monochrome pixel, for example, a known method such as the following (1) or (2) may be used.
(1) A method of comparing the maximum and minimum values of the RGB signal with the threshold value THa
max (R, G, B) −min (R, G, B) ≧ THa (for example, 20)
(2) A method of obtaining an absolute value of a difference between each color component of an RGB signal and comparing it with a threshold value

  The determination results by the document type determination unit 141, the background determination unit 143, and the color determination unit 145 are output as document determination data. More specifically, the document type information by the document type determination unit 141 is output to the color correction unit 17, the spatial filter unit 19, and the halftone generation unit 21. Information on the presence / absence of the background by the background determination unit 143 is output to the background removal unit 15. Information regarding whether the color document is a color document or a monochrome document by the color determination unit 145 is output to the dropout color processing unit 16, the color correction unit 17, the spatial filter unit 19, and the halftone generation unit 21.

  Returning to FIG. 2, the region separation unit 22 performs region separation processing. More specifically, information for specifying a region including a character image in the input image data while distinguishing it from other regions is output. For example, the region separation unit 22 determines the type of region in which each pixel of the input image data is included. The types of regions are, for example, a black character region, a color character region, and a halftone dot region. The determined result is output as region separation data which is data for identifying the type of region.

  The background removal unit 15 performs background removal on the input image data. The background removal may be performed based on a background darkness determination result by the ground surface determination unit 143 or background darkness setting information input from an operation panel (not shown). For example, the background removal unit 15 selects a gradation correction curve for background removal shown in FIG. 5 and performs background removal of the input image data. Note that the background darkness setting information is, for example, darkness level information when the background darkness is expressed in stages.

  The dropout color processing unit 16 executes dropout color processing for removing the erased color from the intermediate image data from which the background has been removed. Note that the dropout color processing unit 16 may perform dropout color processing on input image data that has not undergone background removal.

  The erase color is, for example, a predetermined hue such as “red” or “chromatic color”. The erase color may be determined based on information input from an operation panel (not shown).

  FIG. 6 is a block diagram showing a functional configuration of the dropout color processing unit 16. The dropout color processing unit 16 includes a luminance saturation calculation unit 161, a color determination unit 163, a chromatic / achromatic determination unit 165, and a designated color erasure unit 167.

  The luminance / saturation calculation unit 161 calculates luminance (Lum) and saturation (Chroma) for the processed image data (RGB data). For example, the following formula (2) may be used as the calculation formula.

However, In_R, In_G, and In_B are the R value, G value, and B value (pixel value) of the processed image data,
Coefficient_R, Coefficient_G, and Coefficient_B are coefficients set in advance. For example, the following values may be used.

  The color determination unit 163 performs a color determination process on the processed image data. The color determination process is a process for determining whether or not the color is an erasure color. The erase color may be set in advance by the user, for example. The color determination unit 163 does not perform color determination processing when the erased color is “chromatic”, that is, when all non-achromatic colors are erased.

  The color determination process may be performed, for example, by comparing the magnitude relationship between the input RGB values. Table 1 below shows a method of comparing the sizes of erased colors. For example, if the erase color is red and the following equation (3) is satisfied, it is determined that the pixel is red.

  In Expression (3) and Table 1, R_JudgeR is a threshold value for the input value R when the erase color is red. G_JudgeG is a threshold for the input value G when the erase color is green. B_JudgeB is a threshold value for the input value B when the erase color is blue. When the conditions shown in Table 1 are satisfied, the pixel is determined to be an erased color. The threshold value may be set to a value shown in Table 2 below, for example.

  The chromatic / achromatic determination unit 165 uses the color determination information determined by the color determination unit 163 and the saturation information calculated by the luminance / saturation calculation unit 161 to determine whether a chromatic pixel or an achromatic pixel is used for each pixel. It is determined whether or not. For example, a pixel that is determined to be chromatic is a pixel that is determined to be an erasure color based on the color determination information and has a saturation value that is equal to or greater than a certain value (for example, 10). .

  The designated color erasure unit 167 performs designated color erasure processing using the luminance and saturation calculated by the luminance saturation calculation unit 161. Out_R, Out_G, and Out_B, which are output values of R, G, and B, are obtained by the following equation (4).

  However, Coefficient_OutR, Coefficient_OutG, and Coefficient_OutB are preset coefficients, and may be set to 20, for example.

  When the user designates an erasure color, the color determination unit 163 determines the pixel of the specified erasure color as the specified color, and the chromatic / achromatic determination unit 165 determines that the pixel is chromatic. On the other hand, for pixels determined to be achromatic, Chroma = 0.

  For the pixel determined to be chromatic or the pixel of the specified color, the value of Chroma is greater than 10 (for example, 30 or 40), and the values of Out_R, Out_G, and Out_B are greater than 255 and become 255. Clipped and turns white.

  Further, the achromatic pixels have small Lum and Chroma, and Out_R, Out_G, and Out_B have the same value or close values, and are output as achromatic colors. For pixels that are not specified colors, Chroma is set to “0”, so only the luminance information of RGB is output and output in an achromatic color.

  When character recognition is performed, the color correction unit 17 converts the processed image data processed by the background removal unit 15 or the dropout color processing unit 16 into image data that conforms to display characteristics of a display device (not shown). For example, RGB image data is converted into sRGB image data. The color correction unit 17 performs processing for image data that has not been subjected to dropout color processing when output processing to paper using CMYK toner such as copying is performed (when character recognition is not performed). , Converted into CMY image data which is a complementary color of RGB. The color correction unit 17 may perform different color correction processing for each document type based on the document determination data. The color correction unit 17 may change the color correction processing based on information on whether a color document or a monochrome document.

  The black generation / under color removal unit 18 removes under color from the processed image data converted into CMYK image data by the color correction unit 17 when output processing to paper using CMYK toner such as copying is performed. To convert to CMYK image data.

  The spatial filter unit 19 performs a corresponding filter process for each region included in the processed image data based on the region separation data output from the region separation unit 22. Filter processing is, for example, enhancement processing and smoothing processing. Note that the spatial filter unit 19 may perform different filter processing for each document type based on the document discrimination data, or may perform different filter processing based on information on whether a color document or a monochrome document.

  When character recognition is performed, the output tone correction unit 20 performs tone correction (γ correction) for each region included in the processed image data based on the region separation data. FIG. 7 is a diagram illustrating a γ correction table. FIG. 7A is a γ correction table used for a character region, and FIG. 7B is a γ correction table used for a region other than a character. When output processing to paper using CMYK toner such as copying is performed, output γ correction processing for output to a recording medium such as paper is performed.

  The halftone generation unit 21 performs gradation reproduction processing on CMYK image data when output processing to paper using CMYK toner such as copying is performed. The halftone generation unit 21 generates a halftone by the gradation expression method corresponding to each type of region based on the region separation data. The halftone generation unit 21 may use a different gradation expression method for each document type based on the document discrimination data instead of the region separation data. The halftone generation unit 21 may change the gradation expression method based on information on whether a color document or a monochrome document.

  The character recognition unit 31, the drawing command generation unit 32, and the formatting processing unit 33 perform processing for adding text data to the processed image data. The character recognition unit 31 recognizes a character image included in the processed image data and generates text data. The character recognition unit 31 receives the processed image data of the sRGB image data output from the output tone correction unit 20. The processed image data may or may not have undergone background removal by the background removal unit 15.

  The character recognition unit 31 converts the image data into low-resolution monochrome binary data. More specifically, for example, a luminance value represented by 8 bits is calculated from sRGB image data, and binarization is performed using 128 as a threshold value. Note that the average luminance value may be used as a binarization threshold value for each block including a plurality of pixels. The block is composed of, for example, 5 pixels vertically and horizontally. For resolution conversion, a nearest neighbor method, a bilinear method, or a bicubic method is used for the binarized image data. The character recognition unit 31 further extracts the feature amount of the image data from the low-resolution monochrome binary data, and performs character recognition by comparing with the dictionary data.

  For example, the character recognition unit 31 is configured as one IC that performs character recognition processing. In addition to the luminance value calculation, binarization, and resolution conversion being executed by the character recognition unit 31, each unit that performs luminance value calculation, binarization, and resolution conversion may be provided.

  The drawing command generation unit 32 generates a drawing command for arranging the non-display content on the processed image data based on the character recognition result. The non-display content is, for example, a PDF transparent text.

  The formatting processor 33 generates a format in which non-display content is added to the image of the processed image data. The processed image data after gradation correction output from the output gradation correction unit 20 is imaged, and non-display content is added by the drawing command output from the drawing command generation unit 32. The image is in PDF format, for example, and the non-display content is transparent text.

  The image to which the non-display content is added is transmitted from the transmission / reception device 8 to another device. For example, an image to which non-display content is added is converted into a format attached to an e-mail by a mail processing unit (not shown), and then transmitted as an e-mail from the transmission / reception device 8 via the network. For example, an image to which non-display content is added may be stored in the storage unit 41. Whether to perform e-mail transmission or storage in the storage unit 41 is based on, for example, a setting selected and input by the user. When the user selects e-mail transmission, e-mail transmission is performed, and when the filing mode is selected, the e-mail transmission is stored in the storage unit 41.

  FIG. 8 is a flowchart illustrating the image processing method according to the present embodiment. The image processing method in FIG. 8 is executed by the image processing apparatus 1. The processing from step S101 to step S108 in FIG. 8 is processing when character recognition is performed, and step S101 and step S109 in FIG. 8 are processing when character recognition is not performed. FIG. 9 shows the units to be processed and the data format output by each unit when performing character recognition. FIG. 10 shows each unit that performs processing and the data format that each unit outputs when character recognition is not performed.

  In step S <b> 101 of FIG. 8, preprocessing is performed on the RGB analog signal input from the image input device 5. The preprocessing includes analog / digital conversion processing by the A / D conversion unit 11, processing for removing distortion included in the digital signal by the shading correction unit 12, and γ correction processing executed by the input processing unit 13. . Input image data is generated by the processing of step S101.

  Proceeding to step S102 following step S101, the control unit 42 determines whether or not the execution of the dropout color process is selected. This selection may be based on, for example, information input from an operation unit (not shown) by the user. If execution of the dropout color process is selected, the process proceeds to step S103, and if execution of the dropout color process is not selected, the process proceeds to step S109.

  In step S103 following step S102, the control unit 42 designates an erase color. The designation of the erase color may be based on, for example, information input from an operation unit (not shown) by the user. Progressing to step S104 following step S103, the color determination unit 145 of the document determination unit 14 executes ACS on the input image data.

  Proceeding to step S105 following step S104, the control unit 42 acquires information on whether or not the input image data was generated by reading a color original from the ACS result of the color determination unit 145. If the color original has been read, the process proceeds to step S106, and if the color original has not been read, the process proceeds to step S107.

  In step S106 following step S105, the dropout color processing unit 16 performs a dropout color process. FIG. 11 is a flowchart for explaining dropout color processing. The process of FIG. 11 is executed by the dropout color processing unit 16.

  In step S11 of FIG. 11, the luminance / saturation calculation unit 161 calculates luminance and saturation for the intermediate image data. In step S <b> 12, the control unit 42 determines whether or not extraction of chromatic colors and deletion are selected. This selection is set, for example, when the user inputs in advance from an operation panel (not shown). If it is selected, the process proceeds to step S13. If it is not selected, the process proceeds to step S14.

  In step S <b> 13, the color determination unit 163 performs a color determination process for determining whether each pixel included in the processed image data is an erased color. In step S14, the chromatic / achromatic determination unit 165 performs a determination process for chromatic or achromatic for each pixel using the saturation calculated in step S11. In step S15, the designated color erasing unit 167 erases the designated color based on the chromatic or achromatic result for each pixel determined in step S14, that is, converts the pixel determined to be chromatic into white. Perform the process. As a result, an image from which the designated color is erased is created.

  In addition, you may use the result of the chromatic / achromatic determination which the area | region separation part 22 performs in step S15. In this case, the process of step S14 can be omitted.

  Returning to FIG. 8, in step S107 following step S106 or step S105, image processing for character recognition is executed. Image processing for character recognition is performed by the color correction unit 17, the spatial filter unit 19, and the output tone correction unit 20.

  Progressing to step S108 following step S107, processing for adding text data to the image data is executed. More specifically, first, after the character image included in the processed image data is recognized and the corresponding text data is obtained, the text data is added to the image of the processed image data. FIG. 12 is a flowchart for explaining processing for adding text data to image data. The process of FIG. 12 is executed by the character recognition unit 31, the drawing command generation unit 32, and the formatting processing unit 33.

  In step S21 of FIG. 12, the character recognition unit 31 performs a character recognition process. In step S22, the drawing command generation unit 32 generates a drawing command corresponding to the character recognized in step S21. The drawing command is, for example, transparent text. In step S23, the formatting processor 33 generates an image to which the non-display content is added by using the drawing command generated in step S22.

  Returning to FIG. 8, after the process of step S <b> 108, the image data to which the non-display content is added by the transmission / reception device 8 is transmitted to another device.

  On the other hand, in step S109 following step S102, image processing corresponding to the selected mode is executed. The selected mode is, for example, a copy mode, and the image processing to be executed is, for example, image processing for forming and outputting an image of image data on a medium. This image processing includes a document determination unit 14, a region separation unit 22, a background removal unit 15, a color correction unit 17, a black generation / under color removal unit 18, a spatial filter unit 19, an output tone correction unit 20, and a halftone. It is executed by the generation unit 21.

  In step S109, the processing executed by each unit is as follows. The color correction unit 17 generates processed image data in CMY format from the processed image data in RGB format, and performs processing to improve color reproducibility when performing copy output. The black generation / under color removal unit 18 generates processed image data in CMYK format from processed image data in CMY format. The spatial filter unit 19 performs enhancement processing and smoothing processing on the processed image data. The output tone correction unit 20 performs γ correction for outputting to a recording medium such as paper. The halftone generation unit 21 performs gradation reproduction processing.

  In step S109, the region separation unit 22 determines whether each pixel of the input image data is a region type such as a black character, a color character, a halftone dot, a photographic paper photograph (continuous tone region), and the like. Output data. The region separation data is input to the black generation / undercolor removal unit 18, the spatial filter unit 19, and the halftone generation unit 21, and the processing is switched according to each region type in each unit.

  In step S109, the processed image data in the CMYK format output from the halftone generator 21 is input to the image output device 6, and an image is formed on the medium.

  The drop-out color process is a function for improving the accuracy of character recognition, and is a process for erasing information that affects the recognition accuracy, such as color frame lines, from the document. Therefore, in the above-described image processing apparatus, for example, character priority processing called character mode is performed, and since the output image data may be a monochrome image, dropout color processing is selected in the monochrome output mode and the character mode. Sometimes. However, for example, if character recognition processing is performed after performing dropout color processing on a document composed only of monochrome pixels, character reproducibility deteriorates, such as characters being faded or interrupted. This may lead to a decrease in character recognition accuracy.

  FIG. 13 is a diagram showing an example of character recognition when dropout color processing is selected for an original composed only of monochrome pixels. FIG. 13 shows a character image of the alphabet letter “H” included in the processed image data. If the characters in the document are composed of composite gray (gray made up of C, M, and Y), or if there is misreading of the image input device, the original values of R, G, and B Where should be equal or close, they may be different from each other.

For example, the hatched hatched portion C1 in FIG.
R = G = B or R≈G≈B
And the black portion C2 in FIG.
R ≠ G ≠ B
It is.

  In this case, in the determination based on Expression (2), the black portion C2 in FIG. 13 is easily determined to be chromatic, and the pixels determined to be chromatic are erased, so that the characters are faded or interrupted. Therefore, based on the ACS result of step S104, when it is determined that the image is monochrome in step S105, the dropout color process of step S106 is not performed, and the process of adding text data to the image data of step S108 is performed. do it. Alternatively, in the case of an image forming apparatus having a function of manually selecting ACS, when dropout color processing is selected, ACS is always executed, and dropout color processing is not performed on a monochrome document. May be.

  In ACS, chromatic / achromatic determination is performed, but ACS determines whether it is color or monochrome based on the number of chromatic pixels in the entire document, so the number of chromatic pixels increases locally as in dropout color processing. However, since it is difficult to determine the color, the composite gray and the color misregistration do not greatly affect the ACS determination.

  FIG. 14 is a flowchart illustrating an example different from FIG. 8 of the image processing method according to the present embodiment. The image processing method in FIG. 14 is executed by the image processing apparatus 1. In FIG. 14, the units related to the processing from step S201 to step S211 and the format of the image data output from each unit are shown in FIG. Further, in FIG. 14, the units related to the processing of step S <b> 201 and step S <b> 220 and the format of the image data output from each unit are shown in FIG. 10.

  In step S <b> 201 of FIG. 14, preprocessing is performed on the RGB analog signal input from the image input device 5. The preprocessing includes analog / digital conversion processing by the A / D conversion unit 11, processing for removing distortion included in the digital signal by the shading correction unit 12, and γ correction processing executed by the input processing unit 13. . Input image data is generated by the processing of step S201.

  Proceeding to step S202 following step S201, the control unit 42 determines whether or not execution of the dropout color processing is selected. This selection may be based on, for example, information input from an operation unit (not shown) by the user. If execution of the dropout color process is selected, the process proceeds to step S203. If execution of the dropout color process is not selected, the process proceeds to step S220.

  In step S203 subsequent to step S202, the document determination unit 14 performs document determination processing. More specifically, document type determination, background presence / absence determination, and color determination are performed. FIG. 15 is a flowchart for explaining the details of the document determination process in step S203. In step S31 of FIG. 15, the document type determination unit 141 determines the document type. The document types to be identified are, for example, a character document, a printed photo document, and a character printed photo document in which characters and a printed photo are mixed.

  Progressing to step S32 following step S31, the background determination unit 143 performs background determination processing. More specifically, it is determined whether or not the input image data includes a background. Progressing to step S33 following step S32, the color determination unit 145 performs ACS. That is, it is determined whether the read original is a color original or a monochrome original.

  Returning to FIG. 14, the process proceeds to step S <b> 204 following step S <b> 203, and the control unit 42 determines whether or not a character image is included in the processed image data based on the determination result of step S <b> 31. If a character image is included, the process proceeds to step S205. If a character image is not included, the process ends. If no character image is included, the same processing as step S220 may be executed.

  In step S205 following step S204, the region separation unit 22 performs region separation processing. Progressing to step S206 following step S205, the background removal unit 15 performs background removal processing. The background removal is preferably performed when it is determined in step S32 that there is a background. Progressing to step S207 following step S206, the control unit 42 designates an erasing color. The designation of the erase color may be based on, for example, information input from an operation unit (not shown) by the user.

  Proceeding to step S208 following step S207, the control unit 42 obtains information as to whether or not the input image data is generated by reading a color document from the ACS result by the color determination unit 145. If the color original has been read, the process proceeds to step S209. If the color original has not been read, the process proceeds to step S210.

  In step S209 following step S208, the dropout color processing unit 16 performs dropout color processing on pixels belonging to the character image region. FIG. 16 is a flowchart for explaining the process of performing the dropout color process on the pixels belonging to the character image area performed in step S209. The process of FIG. 16 is executed by the dropout color processing unit 16.

  In step S41 in FIG. 16, the control unit 42 determines whether or not the pixel of the processed image data is included in the character image area. This determination is performed by determining whether or not the pixel corresponding to the pixel of the processed image data of the input image data is included in the character image area based on the output of the area separation process in step S205. If the pixel is included in the character image area, the process proceeds to step S42. If the pixel is not included in the character image area, the process proceeds to step S47.

  Since the processing from step S42 to step S46 subsequent to step S41 is the same as the processing from step S11 to step S15 in FIG. 11, the description is omitted here.

  In step S47 following step S41 or step S46, the control unit 42 determines whether or not the processing of all the pixels included in the processed image data has been completed. If it has been completed, the process ends. If there is a pixel that has not been completed, the process returns to step S41, and the processes from step S41 to step S47 for the unprocessed pixel are repeated.

  Returning to FIG. 14, in step S210 following step S208 or step S209, image processing for character recognition is performed. This process is the same as the process of step S107 in FIG.

  Progressing to step S211 following step S210, a process of adding text data to the image data of the character image region is performed. FIG. 17 is a flowchart for explaining the details of the process of adding text data to the image data of the character image area executed in step S211.

  17 is executed by the control unit 42, the character recognition unit 31, the drawing command generation unit 32, and the formatting processing unit 33. In step S51 of FIG. 17, the control unit 42 determines, for each separated region, whether or not the region is a character image region based on the region separation data output by the region separation unit 22. If it is a character image area, the process proceeds to step S52. If it is not a character image area, the process proceeds to step S55.

  The processing from step S52 to step S54 following step S51 is substantially the same as the processing in FIG. More specifically, the process in FIG. 12 is performed on image data corresponding to an image obtained by reading one original, whereas the processes in steps S52 to S54 are performed on one original. The process is executed on one character image area in the image data corresponding to the image obtained by reading.

  Proceeding to step S55 following step S54, the control unit 42 confirms whether there is an unprocessed area. If there is an unprocessed area, the process returns to step S51 to repeat the process for the unprocessed area. If there is no unprocessed area, the process ends.

  Returning to FIG. 14, the process of step S220 following step S202 is the same as the process of step S109 of FIG.

  In FIG. 14, the discrimination of the document type and the dropout color function are executed in combination. Since there are color characters in the document that is subject to dropout color processing, this is combined with the determination of the document type. The dropout color process can be executed only when it is determined to be “character photographic paper original”. That is, when it is determined that the document is a character document, a character-printed photographic document, or a character photographic paper photographic document, the region separation unit 22 extracts pixels determined to be characters (or character edges) and performs dropout color processing. Just do it.

  In the area separation process, the above-described methods (1) to (6) for determining the document type may be used. As a result, for a document that does not include characters that are not subject to dropout color processing, for example, the dropout color setting may be disabled or output.

  In the above, the case of the configuration including the document determination unit 14 and the region separation unit 22 has been described, but the configuration including only the region separation unit 22 may be used. That is, the region separation process is performed using the methods (1) to (6) for determining the document type, the pixels determined to be characters (or character edges) are extracted, and the dropout color process is performed. May be.

In FIG. 14, the background removal and the dropout color function are combined and executed.
For example, in the case of image data in which a pale background or show-through represented by a newspaper or the like remains in a document, the background or show-through may be erroneously recognized as a character during character recognition. Therefore, by performing background removal processing, information that is not characters can be eliminated, and the accuracy of character recognition can be improved.

  Background removal is performed by the background removal unit 15 based on the background determination result of the document determination unit 14. Specifically, as shown in FIG. 5, a gradation correction curve that removes the background is selected based on the background determination result in the document determination unit, and the background is removed.

  The background removal unit 15 may be provided before the dropout color processing unit 16 or may be provided after the dropout color processing unit 16. If dropout color processing is performed after the background removal, the accuracy of dropout color processing and character recognition is improved. Further, if the background is removed after the dropout color processing is performed, the accuracy of character recognition is improved. When the result of the dropout color process is improved, the accuracy of character recognition is also improved. Therefore, it is preferable to adopt the former configuration.

  FIG. 18 is a diagram for explaining an example of the hardware configuration of the image forming apparatus 900 according to this embodiment. The image forming apparatus 900 of FIG. 18 includes an image processing unit 910, a scanner 920, a hard disk device 930, a drive device 940, and a printer 980. The image processing unit 910 controls each unit connected to the image processing unit 910 and processes image data output from the image forming apparatus 900.

  The image processing unit 910 includes a CPU 901, ROM 902, RAM 903, image processing ASIC 904, character recognition IC 905, scanner interface (hereinafter referred to as “scanner I / F”) 912, HDD interface (hereinafter referred to as “HDD-I / F”). 913, a drive interface (hereinafter referred to as “drive I / F”) 914, a printer interface (hereinafter referred to as “printer I / F”) 918, and a communication interface (hereinafter referred to as “communication I / F”). . 919.

  The CPU 901 controls each unit of the image processing unit 910 and each unit connected to the image processing unit 910 by executing a computer program. For example, the ROM 902 stores a computer program executed by the CPU 901. The ROM 902 may also store image data processed by the image processing ASIC 904, the character recognition IC 905, and a function realized by the CPU 901 executing a computer program.

  The CPU 901 may also realize a function of performing an automatic document determination process, a drawing command generation process, and an image generation process with non-display content added.

  The RAM 903 stores image data processed by the image processing ASIC 904, the character recognition IC 905, and a function realized by the CPU 901 executing a computer program.

  The image processing ASIC 904 performs various processes on the image data. The image processing ASIC 904 is, for example, at least one of region separation processing, background removal processing, color correction processing, black generation / undercolor removal processing, spatial filter processing, output tone correction processing, and halftone generation processing. I do. The character recognition IC 905 performs character recognition processing.

  The scanner I / F 912 receives image data input from the scanner 920 and performs image processing according to the characteristics of the scanner 920. The HDD-I / F 913 inputs and outputs image data stored in the HDD 930 based on the control of the CPU 901. The drive I / F 914 inputs / outputs data to / from the portable recording medium 941 inserted into the drive device 940.

  A printer I / F 918 is an interface for outputting image data processed by the image processing unit 910 to the printer 980. A communication I / F 919 is an interface for communicating image data or a control signal with another apparatus from the image processing unit 910 via the network 990.

  The scanner 920 optically reads a document on which an image is formed on a medium and outputs image data. Image data output from the scanner 920 may be an analog signal or a digital signal obtained by converting the analog signal.

  The HDD 930 stores image data processed by the image processing unit 910. The HDD 930 stores, for example, image data input from the scanner 920, image data input from the communication I / F 919, and intermediate image data generated by processing of the CPU 901, the image processing ASIC 904, and the character recognition IC 905. . The drive device 940 writes and reads data to and from the portable recording medium 941 by inserting the portable recording medium 941. The portable recording medium 941 stores a computer program executed by the CPU 901, for example.

  The printer 980 forms and outputs the image data processed by the image processing unit 910 on a medium.

<Computer program and recording medium>
The image processing apparatus according to the present embodiment may be realized by a computer executing a program code (execution format program, intermediate code program, source program). The recording medium of the present embodiment is a computer-readable recording medium in which a program code is recorded, and a computer program for executing an image processing method for confirming setting conditions on a setting confirmation screen for various parameters is recorded. It can also be done. The various parameters are, for example, (1) a parameter that is not reflected in the preview image, and (2) a parameter whose effect is not known even when previewed.

  A recording medium on which a program for performing the image processing method according to this embodiment is recorded can be provided in a portable manner.

  The recording medium may be a memory (not shown) such as a ROM in which program codes for processing by the microcomputer are recorded. The recording medium may also be a program medium that can be read by a computer by being inserted into a program reading device provided as an external storage device (not shown).

  The program code stored in the recording medium may be configured to be executed by the microprocessor accessing the recording medium. Further, the program code may be read from the recording medium, downloaded to a program storage area (not shown), and the program code may be executed. It is assumed that the download program is stored in the apparatus in advance.

  A program medium as a recording medium is configured to be separable from the apparatus. For example, tape systems such as magnetic tapes and cassette tapes, magnetic disks such as flexible disks and hard disks, optical disk systems such as CD-ROM / MO / MD / DVD, IC cards (including memory cards) / optical cards, etc. Any medium of a card system and a fixed ROM including a semiconductor memory such as a mask ROM, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), flash ROM, etc. may be carried.

  Further, the image processing apparatus according to the present embodiment may have a system configuration capable of connecting a communication network including the Internet. In this case, the recording medium is fluidly programmed when downloading the program code from the communication network. It may also be a medium carrying In the case of downloading the program code from the communication network, the download program may be stored in the main device in advance or installed from another recording medium. The computer program according to the present embodiment can also be realized in the form of a computer data signal embedded in a carrier wave, in which the program code is embodied by electronic transmission.

  The correspondence between each part described in the above embodiments and the configuration according to the claims is as follows. The “color determination unit” corresponds to the “color determination unit 145”. The “control unit” corresponds to the “control unit 42”. The “character determination unit” corresponds to the “document type determination unit 141”. The “character area specifying part” corresponds to the “area separating part 22”. The “background determination unit” corresponds to the “background determination unit 143”. The “background removal unit” corresponds to the “background removal unit 15”.

  As mentioned above, although the form for inventing was demonstrated, this invention is not limited to embodiment described in the form for implementing this invention. Modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 5 Image input apparatus 6 Image output apparatus 8 Transmission / reception apparatus 10 Image processing part 11 A / D conversion part 12 Shading correction part 13 Input processing part 14 Original determination part 141 Original type determination part 143 Background determination part 145 Color determination part DESCRIPTION OF SYMBOLS 15 Background removal part 16 Dropout color processing part 161 Luminance saturation calculation part 163 Color determination part 165 Chromatic / achromatic determination part 167 Designated color erasure part 17 Color correction part 18 Black generation / under color removal part 19 Spatial filter part 20 Output Tone correction unit 21 Halftone generation unit 22 Region separation unit 31 Character recognition unit 32 Drawing command generation unit 33 Formatting processing unit 41 Storage unit 42 Control unit

Claims (11)

In an image processing apparatus having a dropout color processing unit that performs dropout color processing prior to character recognition processing,
A color determination unit for determining whether the input image data is image data generated by reading from a color document or a monochrome document;
When the color determination unit determines that the input image data is image data generated by reading from a monochrome document, character recognition is performed without executing dropout color processing on the image data related to the input image data. An image processing apparatus comprising: a control unit that determines execution of processing. A character determination unit for determining whether or not a character image is included in the input image data;
The control unit determines that the color determination unit determines that the input image data has been read and generated from a color document, and further determines that the input image data includes a character image. The image processing apparatus according to claim 1, wherein the image processing apparatus is configured to determine to perform dropout color processing and character recognition processing on image data related to the input image data. A character area specifying unit for specifying an area including a character image in the input image data;
The control unit determines to execute the dropout color process and the character recognition process on an area corresponding to the area specified by the character area specifying unit in the image data related to the input image data. The image processing apparatus according to claim 1, wherein the image processing apparatus is configured. A background determination unit that determines whether a background image is included in the input image data;
A background removal unit that performs background removal on the image data related to the input image data when the background determination unit determines that the input image data includes a background image;
3. The image according to claim 1, wherein the control unit is configured to perform dropout color processing and character recognition processing on the image data after the background removal unit removes the background. 4. Processing equipment. An image processing unit comprising the image processing apparatus according to any one of claims 1 to 4, and further performing image processing for forming an image of the image data on a medium with respect to the image data;
An image forming apparatus, comprising: an image forming unit that forms an image of image data on which the image processing has been performed on a medium and outputs the image. Determining whether input image data is image data generated by reading from a color document or a monochrome document, and determining whether or not to perform dropout color processing performed prior to character recognition processing An image processing control device to execute,
When the input image data is determined to be image data generated by reading from a monochrome document, a character recognition process is executed without executing a dropout color process on the image data related to the input image data. An image processing control apparatus comprising a control unit for determining An image processing control method for selecting whether or not to execute dropout color processing prior to character recognition processing,
Determining whether the image data is image data generated by reading from a color document or a monochrome document;
In this step, when it is determined that the image data is generated by reading from a monochrome document, the character recognition process is executed without executing the dropout color process on the image data related to the image data. An image processing control method comprising the steps of: In a computer program for causing a computer to select whether or not to execute dropout color processing preceding character recognition processing,
On the computer,
A color determination step of determining whether the input image data is image data generated by reading from a color original or a monochrome original;
In the color determination step, if the input image data is determined to be image data generated by reading from a monochrome document, character recognition is performed without executing dropout color processing on the image data related to the input image data. A computer program for executing the step of deciding to execute the process. In the computer,
A character determination step for determining whether or not a character image is included in the input image data;
In the color determination step, it is determined that the input image data has been read and generated from a color document, and further, in the character determination step, it is determined that the input image data includes a character image. The computer program according to claim 8, further comprising: a step of determining that the dropout color process and the character recognition process are to be performed on the image data related to the image data. In the computer,
A character determination step for determining whether or not a character image is included in the input image data;
A character region specifying step for specifying a region including a character image in the input image data;
In the color determination step, it is determined that the input image data has been read and generated from a color document, and further, in the character determination step, it is determined that the input image data includes a character image. A step for further executing a step of determining that a dropout color process and a character recognition process are to be executed on an area corresponding to the area specified in the character area determination step in the image data related to the image data. The computer program according to 8 or 9.   A computer-readable recording medium on which the computer program according to any one of claims 8 to 10 is recorded.

Images