JP2015050499A - Image processing apparatus and image processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus and an image processing program with which an output result consistent with a blank paper determination result can be expected.SOLUTION: When a multi-value image is acquired by an image acquisition unit 20 and subjected to image processing and thereafter an image after the image processing is generated, binary conversion by a binary conversion unit 517 and binary determination are executed. When it is determined in the binary determination that a BW binary image is a blank paper image, the BW binary image is not output. When it is determined in the binary determination that the BW binary image is not a blank paper image, the BW binary image is output.

Description

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

  2. Description of the Related Art Conventionally, there is known an image processing apparatus that reads an image of a document and executes a process of outputting the image to a sheet or display.

  Some image processing apparatuses of this type are equipped with a blank page determination function for determining whether or not a document is a blank page document (see, for example, Patent Document 1). By mounting the blank page determination function, for example, it is possible to output an image of a document that is not a blank document and not to output an image of a blank document.

JP 2008-219808 A

  However, depending on the contents of processing executed by the image processing apparatus, a blank image may be output even though it is determined that the document is not a blank document, and the blank page determination result may not match the output result. For example, when a process of converting an image of a document into a binary image is executed, all pixels of the document are converted into white pixels, and as a result, a blank image may be output.

  An object of the present invention is to provide an image processing apparatus and an image processing program capable of expecting an output result consistent with a blank page determination result.

  In order to achieve the above object, an image processing apparatus according to one aspect of the present invention includes an acquisition unit that acquires a multi-valued image as an acquired image, and a control unit, and the control unit converts the acquired image into a binary image. A binary conversion process for converting the binary image into a binary determination process, a binary determination process for determining whether the binary image is a blank image based on the binary image obtained by the binary conversion process, and a binary determination process If the binary image obtained by the binary conversion process is determined to be a blank image, the binary image obtained by the binary conversion process is not output in the binary determination process without outputting the binary image. If it is determined that the image is not a blank image, a binary output process for outputting the binary image is executed.

  According to this configuration, when a multi-value image is acquired as an acquired image by the acquisition unit, a binary conversion process and a binary determination process are executed. In the binary conversion process, the acquired image is converted into a binary image. In the binary determination process, it is determined based on the binary image obtained by the binary conversion process whether the binary image is a blank paper image.

  When it is determined that the binary image obtained by the binary conversion process is a blank image, the binary image is not output. Therefore, the blank page determination result by the binary determination process matches the result that the image is not output by blank page removal. On the other hand, when it is determined that the binary image obtained by the binary conversion process is not a blank paper image, the binary image is output. Therefore, the blank sheet determination result obtained by the binary determination process and the result that the binary image is output coincide.

  Therefore, an output result that is consistent with the blank sheet determination result can be expected.

  In the binary determination process, the control unit determines that the binary image obtained by the binary conversion process is not a blank image when the number of pixels converted to black pixels by the binary conversion process is equal to or greater than a predetermined threshold. May be.

  According to this configuration, by counting the number of pixels converted to black pixels by the binary conversion process and comparing the counted number of pixels with a threshold value, the binary image obtained by the binary conversion process is blank. Whether or not the image is an image can be easily determined. Further, since the binary determination method is simple, it is possible to expect a high speed binary determination process.

  When executing a compression process for compressing a binary image obtained by the binary conversion process, the control unit performs a binary determination process when the size of the binary image compressed by the compression process is equal to or larger than a predetermined threshold value. The binary image obtained by the binary conversion process may be determined not to be a blank paper image.

  As the number of white pixels included in the binary image increases, the compression rate of the binary image increases and the size of the binary image after compression decreases.

  According to this configuration, it is possible to easily determine whether or not the binary image obtained by the binary conversion process is a blank image by comparing the size of the binary image after compression with a threshold value. . Further, since the binary determination method is simple, it is possible to expect a high speed binary determination process.

  Based on the acquired image, the control unit determines whether the acquired image is a blank image, multi-value determination processing, multi-value output processing that outputs a multi-value image, and multi-value output processing. Multi-value conversion processing for converting to a multi-valued image that is output in this way. In multi-value output processing, if the multi-value determination processing determines that the acquired image is a blank image, the image is output. Without determining that the acquired image is not a blank image in the multi-value determination process, a multi-value image obtained by the multi-value conversion process may be output.

  According to this configuration, when a multi-value image is acquired as an acquired image by the acquisition unit, multi-value conversion processing and multi-value determination processing are executed. In the multi-value conversion process, the acquired image is converted into a multi-value image output in the output process. In the multilevel determination process, it is determined whether or not the acquired image is a blank paper image based on the acquired image that is an image before being converted into the multilevel image.

  If it is determined that the acquired image is a blank image, no image is output. For this reason, the blank sheet determination result by the multi-value determination process and the result that the image is not output by blank sheet removal match. On the other hand, when it is determined that the acquired image is not a blank image, a multi-value image obtained by multi-value conversion processing is output. Therefore, the blank sheet determination result by the multi-value determination process and the result that the multi-value image is output coincide.

  Therefore, an output result that is consistent with the blank sheet determination result can be expected.

  In the multilevel determination process, the control unit may determine whether the acquired image is a blank image based on the luminance component data of the acquired image.

  An image processing program according to another aspect of the present invention includes a binary conversion process for converting an acquired image into a binary image to a computer connected to an image processing apparatus including an acquisition unit that acquires a multi-valued image as an acquired image. Based on the binary image obtained by the binary conversion process, the binary determination process determines whether the binary image is a blank image, and the binary conversion process obtains the binary conversion process. If the binary image is determined to be a blank image, the binary image is not output, and it is determined that the binary image obtained by the binary conversion process is not a blank image in the binary determination process. If it is, the binary output process for outputting the binary image is executed.

  In a computer in which this image processing program is installed, when a multi-value image is acquired as an acquired image by the acquisition unit, a binary conversion process and a binary determination process are executed. In the binary conversion process, the acquired image is converted into a binary image. In the binary determination process, it is determined based on the binary image obtained by the binary conversion process whether the binary image is a blank paper image.

  When it is determined that the binary image obtained by the binary conversion process is a blank image, the binary image is not output. Therefore, the blank page determination result by the binary determination process matches the result that the image is not output by blank page removal. On the other hand, when it is determined that the binary image obtained by the binary conversion process is not a blank paper image, the binary image is output. Therefore, the blank sheet determination result obtained by the binary determination process and the result that the binary image is output coincide.

  Therefore, an output result that is consistent with the blank sheet determination result can be expected.

  According to the present invention, it is possible to expect an output result that is consistent with the blank sheet determination result.

1 is a block diagram illustrating a configuration of an MFP (Multi-Function Peripheral) according to an embodiment of the present invention. FIG. It is a block diagram which shows the structure of a control part. It is a flowchart which shows the flow of a reading process. It is a flowchart which shows the content of a block setting process. It is a flowchart which shows the content of the initial setting process. It is a flowchart which shows the content of an auto setting process. It is a flowchart which shows the content of a color setting process. It is a flowchart which shows the content of a mono setting process. It is a flowchart which shows the flow of the output process at the time of auto. It is a flowchart which shows the flow of the output process at the time of a manual. It is a flowchart which shows the flow of a blank paper non-removal process. It is a flowchart which shows the flow of a binary determination process. It is a flowchart which shows the other example of a binary determination process.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Hardware configuration>

  As shown in FIG. 1, an MFP (Multi-Function Peripheral) 1 as an example of an image processing apparatus includes an image forming unit 10, an image reading unit 20, an operation panel 30, a network interface (I / F) 40, and a control unit. 50.

  The image forming unit 10 performs printing (color printing or monochrome printing) based on image data, and forms an image on a print sheet or the like. The image forming method may be an electrophotographic method or an inkjet method.

  An image reading unit 20 as an example of an acquisition unit reads an image of a document and generates image data. The reading method may be an ADF (Auto Document Feeder) method that reads an image of a document while conveying the document, or an FB (Flat Bed) that reads a document image by placing the document on a contact glass. ) Method.

  The operation panel 30 includes a touch panel. Various information is displayed on the touch panel. Various inputs can be made by touch operations on the touch panel. The operation panel 30 may be provided with input keys such as a numeric keypad.

Since the MFP 1 includes the network interface 40, a LAN (Local
Communication via an LAN is possible with an external device such as a PC (personal computer) connected to an area network.

The control unit 50 includes a CPU 51, ROM 52, RAM 53, NVRAM (Non
Volatile RAM) 54 and ASIC 55 are provided. The CPU 51 controls the image forming unit 10, the image reading unit 20, and the operation panel 30 by executing programs for various processes, and controls data communication through the network interface 40. The ROM 52 stores programs executed by the CPU 51 and various data. The RAM 53 is used as a work area when the CPU 51 executes a program. The NVRAM 54 stores various setting values input from the operation panel 30.

<Functions and settings>

  The MFP 1 reads an image of a document by the image reading unit 20 and outputs the read image (image data) to a print sheet or the like by the image forming unit 10 or outputs it to an external PC or the like via the network interface 40. Reading function.

  When using the reading function, the user can set the scan type by operating the operation panel 30. There are four scan types: BW (monochrome), gray, color and auto. When “scan type: BW” is set, the image of the document is read as a monochrome binary image (BW image), and a BW binary image is output. When “scan type: gray” is set, the image of the document is read as a gray image that is a black and white image having an intermediate gradation, and a 256-level gray Jpeg image is output. When “scan type: color” is set, the image of the document is read as a color image, and a 256-level color Jpeg image is output. When “scan type: auto” is set, it is automatically determined whether the image type of the document is a BW image, a gray image, or a color image, and an image corresponding to the determination result is output.

  Note that the gray number of the gray Jpeg image and the color Jpeg image is an example, and the number of gradations may be smaller than 256 gradations, or may be larger than 256 gradations. Further, the gray Jpeg image and the color Jpeg image are files in the Jpeg format, but the file format of the output image may be a file format other than the Jpeg format, such as a Tiff format, XPS format, or PDF format.

  Further, the MFP 1 has a blank paper removal function. The blank sheet removal function is a function that determines whether or not the image of the document read by the image reading unit 20 is a blank sheet image, and does not output a blank sheet image if it is a blank sheet image. The user can set whether to enable or disable the blank sheet removal function by operating the operation panel 30.

<Configuration of control unit>

  The CPU 51 of the control unit 50 executes the program, thereby causing the CIS control unit 511, the reading correction unit 512, the image processing unit 513, the blank sheet determination unit 514, the color number detection unit 515, the Jpeg compression unit 516, and the like shown in FIG. The function of the binary conversion unit 517 is realized.

The CIS control unit 511 is a CIS (Contact
An image sensor 201 and an AFE (Analog Front End) 202 are controlled. As a control mode of the CIS control unit 511, a color mode suitable for reading a color image and a mono mode suitable for reading a BW image and a gray image are provided. When the CIS control unit 511 controls the CIS 201 and the AFE 202, an analog image signal corresponding to the reflected light from the document is output from the CIS 201. In the AFE 202, the analog image signal is 8-bit (0 to 255) digital image data. Is converted to

  A reading correction unit 512 performs reading correction to eliminate unevenness in the amount of light (illumination unevenness) applied to the document and unevenness in pixel density due to other causes with respect to the image (8-bit digital image data) output from the AFE 202. (Shading correction) is performed. As a correction mode of the reading correction unit 512, a color mode for performing reading correction suitable for a color image and a mono mode for performing reading correction suitable for a BW image and a gray image are provided. The read correction unit 512 stores the read corrected image in the RAM 53.

  The image processing unit 513 performs various types of image processing on the read corrected image. As processing modes of the image processing unit 513, a color mode for performing image processing suitable for a color image and a mono mode for performing image processing suitable for a BW image and a gray image are provided. The image processing includes, for example, edge enhancement processing for enhancing the edge of the image, resolution changing processing for changing the resolution of the image, and color conversion processing for converting the color space of the image from RGB to YCbCr. The image processing unit 513 stores the image-processed image in the RAM 53.

  Further, the image processing unit 513 divides the image after color conversion processing into a plurality of blocks in a grid shape, for example, with 100 × 100 pixels as one block, and for each block, a histogram of Y component (luminance component), Cb A histogram of the component (color difference data) and a histogram of the Cr component (color difference data) are created. Then, the image processing unit 513 stores the Y component histogram, the Cb component histogram, and the Cr component histogram created for each block in the RAM 53.

  The blank page determination unit 514 determines whether the image after the color conversion processing by the image processing unit 513 is a blank page image.

  Specifically, the blank page determination unit 514 refers to the histogram of the Y component for each block stored in the RAM 53 and obtains the mode value of the Y component for each block. In the almost white block, the mode value of the Y component is concentrated in the vicinity of 255. When the entire image is substantially white, when the histogram of the Y component mode values for each block is created, the mode values in the histogram are concentrated in the vicinity of 255. Therefore, the blank page determination unit 514 obtains the number of blocks having the mode value of the Y component that matches the “mode value in the histogram of the mode value of the Y component for each block”, and the number of blocks is greater than or equal to a certain value. If so, it is determined that the image after the color conversion process is a blank image. Then, the blank paper determination unit 514 stores the determination result in the RAM 53. Hereinafter, the determination by the blank sheet determination unit 514 is referred to as “multi-value determination”.

  If the blank page removal function is set to invalid, the blank page determination unit 514 is set to invalid and multi-value determination is not performed.

  The color number detection unit 515 performs color number detection, and determines whether the image type after the color conversion processing by the image processing unit 513 is a BW image, a gray image, or a color image.

  Specifically, the color number detection unit 515 determines whether each block stored in the RAM 53 is a chromatic color block or an achromatic color block. In the YCbCr color space, when the range of the Cb component value and the Cr component value is 0 to 255, the Cb component value and the Cr component value are each in the vicinity of a substantially intermediate value (= 127). The color becomes close to achromatic. Therefore, the color number detection unit 515 refers to the Cb component histogram and the Cr component histogram for each block, and, for example, if both of the following expressions (1) and (2) are satisfied, If at least one of the following expressions (1) and (2) is not satisfied, it is determined that the block is a chromatic color block.

  112 ≦ average value of Cb components <143 (1)

  112 ≦ Average value of Cr component <143 (2)

  The numerical values in the formulas (1) and (2) are merely examples, and may be changed as appropriate. The same applies to the following formula (3).

  Thereafter, the number-of-colors detection unit 515 determines whether each achromatic color block is a BW block or a gray block. In the YCbCr color space, when the Y component value, the Cb component value, and the Cr component value ranges from 0 to 255, the Cb component value and the Cr component value are approximately intermediate values (= 127), respectively. When the value of the Y component is closer to 0, the color of the pixel is closer to black, and as the value of the Y component is closer to 255, the color of the pixel is closer to white. Therefore, the color number detection unit 515 refers to the Y component histogram for each achromatic color block and, for example, determines that the block is a BW block if the following equation (3) is satisfied. If is not satisfied, it is determined as a gray block.

“Percentage of pixels satisfying Y component value <63 or 224 ≦ Y component value” ≧ 40%
... (3)

  Then, the number-of-colors detection unit 515 determines whether the mode values of the Cb component and the Cr component in the image after image processing (one page image) are both in the range of 112 or more and less than 143, or after image processing When the image contains a color block of a certain ratio (for example, 0.2%) or more, it is determined that the type of the image after image processing is a color image. At least one of the mode values of the Cb component and Cr component in the image after image processing is outside the range of 112 or more and less than 143, and the ratio of gray blocks in the image after image processing is constant (for example, 0. 3%) or more, it is determined that the type of image after image processing is a gray image. In addition, at least one of the mode values of the Cb component and the Cr component in the image after image processing is outside the range of 112 or more and less than 143, and the proportion of gray blocks in the image after image processing is less than a certain value. In this case, it is determined that the image type after image processing is a BW image.

  When “scan type: auto” is set, the color number detection unit 515 is enabled, and “scan type: BW”, “scan type: gray”, and “scan type: color” are set. If the color number is detected, the color number detection unit 515 is disabled. When the color number detection unit 515 is set to invalid, the above-described determination by the color number detection unit 515 is not performed.

  The Jpeg compression unit 516 compresses the image after image processing stored in the RAM 53 using the Jpeg method, and generates a gray Jpeg multi-value image or a color Jpeg multi-value image.

  Specifically, the operation mode of the Jpeg compression unit 516 includes a mode for generating only a gray Jpeg multi-valued image and a mode for generating only a color Jpeg multi-valued image. Each operation mode is selectively enabled. Set or all operating modes are disabled. When “scan type: BW” is set, all the operation modes of the Jpeg compression unit 516 are set to be invalid, and the Jpeg compression unit 516 generates neither a gray Jpeg multi-value image nor a color Jpeg multi-value image. . When “scan type: gray” is set, the mode for generating only the gray Jpeg multi-valued image is set to valid (gray), and the Jpeg compression unit 516 generates only the gray Jpeg multi-valued image. When “scan type: color” is set, the mode for generating only a color Jpeg multi-valued image is set to valid (color), and the Jpeg compression unit 516 generates only a color Jpeg multi-valued image. When “scan type: auto” is set, a mode for generating a gray Jpeg multi-valued image or a color Jpeg multi-valued image is set to valid (color / gray), and the Jpeg compression unit 516 detects the number of colors. According to the determination result of the unit 515, either a gray Jpeg multi-valued image or a color Jpeg multi-valued image is generated. Then, the Jpeg compression unit 516 stores the generated gray Jpeg multi-valued image or color Jpeg multi-valued image in the RAM 53.

  The binary conversion unit 517 performs binary conversion on the image after image processing that is set valid and stored in the RAM 53 when “scan type: BW” or “scan type: auto” is set. A BW binary image is generated. The binary conversion method is so-called simple binarization, and the binary conversion unit 517 determines that each pixel of the image after image processing is a white pixel if the Y component value is equal to or greater than a certain threshold value. If the value of the Y component is less than the threshold value, the pixel is converted to a black pixel. The binary conversion unit 517 stores the generated BW binary image in the RAM 53. When “scan type: gray” or “scan type: color” is set, the binary conversion unit 517 is disabled, and the binary conversion unit 517 does not generate a BW binary image.

  In addition, the binary conversion unit 517 executes a binary determination process described later, and determines whether or not the BW binary image is a blank paper image. Hereinafter, the determination by the binary conversion unit 517 is referred to as “binary determination”.

<Reading process>

  When the user operates the operation panel 30 and inputs an instruction to read an image of a document, the CPU 51 of the control unit 50 executes the reading process shown in FIG. 3 for each page of the document.

  In the reading process, the CPU 51 executes a block setting process (S1). The block setting process will be described later.

  After completion of the block setting process, the CPU 51 starts a document reading operation by the image reading unit 20 (S2). With the start of this reading operation, processing by the CIS controller 511 shown in FIG. 2 is started.

  Thereafter, the CPU 51 determines whether or not reading of one page of the document is completed (S3). When an image of a document is read by the ADF method, for example, it is determined that one page (one sheet) of the document has passed through the CIS 201 of the image reading unit 20 and thus reading of one page of the document is completed. Can do. Further, when an image of an original is read by the FB method, for example, it can be determined that reading of one page of the original is completed when the CIS 201 makes one reciprocation in the sub-scanning direction.

  If reading of one page of the document is not completed (S3: NO), the process returns to S3 again. When reading of one page of the document is completed (S3: YES), processing by the reading correction unit 512 and the image processing unit 513 is performed. Be started. Further, the CPU 51 determines whether or not the blank sheet removal function is set to be effective (S4).

  When the blank paper removal function is set to be valid (S4: YES), the CPU 51 determines whether “scan type: auto” is set (S5).

  When “scan type: auto” is set, a mode for generating a gray Jpeg multi-valued image or a color Jpeg multi-valued image is effective as an operation mode of the Jpeg compression unit 516 in an auto setting process described later (color / Gray) and the binary conversion unit 517 is set to be valid.

  If “scan type: auto” is set (S5: YES), the CPU 51 executes an auto-time output process (S6) and ends the reading process. The auto output process will be described later.

  If “scan type: auto” is not set (S5: NO), the CPU 51 executes a manual output process (S7) and ends the reading process. The manual output process will be described later.

  On the other hand, if the blank sheet removal function is set to be invalid (S4: NO), the CPU 51 executes blank sheet non-removal processing (S8) and ends the reading processing. The blank paper non-removal process will be described later.

<Block setting process>

  The contents of the block setting process executed in step S1 shown in FIG. 3 are shown in FIG.

  In the block setting process, the CPU 51 executes an initial setting process (S11). The initial setting process will be described later.

  After completion of the initial setting process, the CPU 51 determines whether or not “scan type: auto” is set (S12).

  When “scan type: auto” is set (S12: YES), the CPU 51 executes an auto setting process (S13). The auto setting process will be described later.

  When “scan type: auto” is not set (S12: NO), the CPU 51 determines whether “scan type: color” is set (S14).

  When “scan type: color” is set (S14: YES), the CPU 51 executes a color setting process (S15). The color setting process will be described later.

  When neither “scan type: auto” nor “scan type: color” is set (S14: NO), the CPU 51 executes mono setting processing (S16). The mono setting process will be described later.

  After completion of the auto setting process, color setting process, or mono setting process, the CPU 51 determines whether or not the blank sheet removal function is set to be valid (S17).

  If the blank page removal function is set to be valid (S17: YES), the CPU 51 sets the blank page determination unit 514 to be valid (S18) and ends the block setting process.

  If the blank sheet removal function is not set to be invalid (S17: NO), the process of step S18 is skipped, and the block setting process is terminated without setting the blank sheet determination unit 514 to be valid.

<Initial setting process>

  The contents of the initial setting process executed in step S11 shown in FIG. 4 are shown in FIG.

  In the initial setting process, the CPU 51 invalidates all of the JPEG compression unit 516, the binary conversion unit 517, the blank page determination unit 514, and the color number detection unit 515 (S111, S112, S113, S114), and ends the initial setting process. To do.

<Auto setting process>

  The contents of the auto setting process executed in step S13 shown in FIG. 4 are shown in FIG.

  In the auto setting process, the CPU 51 performs the following various settings.

  The control mode of the CIS control unit 511 is set to a color mode suitable for reading a color image (S131).

  The correction mode of the reading correction unit 512 is set to a color mode for performing reading correction suitable for a color image (S132).

  The processing mode of the image processing unit 513 is set to a color mode for performing image processing suitable for a color image (S133).

  As an operation mode of the Jpeg compression unit 516, a mode for generating a gray Jpeg multi-valued image or a color Jpeg multi-valued image is set to valid (color / gray) (S134).

  The binary conversion unit 517 is set to be valid (S135).

  The color number detection unit 515 is set to be effective (S136).

<Color setting process>

  The contents of the color setting process executed in step S15 shown in FIG. 4 are shown in FIG.

  In the color setting process, the CPU 51 performs the following various settings.

  The control mode of the CIS controller 511 is set to a color mode suitable for reading a color image (S151).

  The correction mode of the reading correction unit 512 is set to a color mode for performing reading correction suitable for a color image (S152).

  The processing mode of the image processing unit 513 is set to a color mode for performing image processing suitable for a color image (S153).

  As an operation mode of the Jpeg compression unit 516, a mode for generating only a color Jpeg multi-valued image is set to valid (color) (S154).

<Mono setting process>

  The contents of the mono setting process executed in step S16 shown in FIG. 4 are shown in FIG.

  In the mono setting process, the CPU 51 sets the control mode of the CIS control unit 511 to a mono mode suitable for reading a BW image and a gray image (S161).

  Further, the correction mode of the reading correction unit 512 is set to a mono mode for performing reading correction suitable for the BW image and the gray image (S162).

  Further, the processing mode of the image processing unit 513 is set to a mono mode for performing image processing suitable for the BW image and the gray image (S163).

  Thereafter, the CPU 51 determines whether or not “scan type: gray” is set (S164).

  When “scan type: gray” is not set (S164: NO), the CPU 51 sets the binary conversion unit 517 to be valid (S165).

  Then, the CPU 51 ends the mono setting process.

  When “scan type: gray” is set (S164: YES), the CPU 51 sets the mode for generating only a gray Jpeg multi-valued image to be valid (gray) as the operation mode of the Jpeg compression unit 516. (S166), the mono setting process is terminated.

<Automatic output processing>

  The flow of the automatic output process executed in step S6 shown in FIG. 3 is shown in FIG.

  In the automatic output process, the CPU 51 determines whether or not the determination result of the color number detection unit 515 is “BW image” (S61).

  When the determination result of the color number detection unit 515 is “BW image” (S61: YES), following the determination of the color number detection unit 515, the BW binary image by the function of the binary conversion unit 517 is displayed. Generation and binary determination are performed. Further, the generated BW binary image is stored in the RAM 53. Then, the CPU 51 determines whether or not the result of the binary determination by the binary conversion unit 517 is “blank image” (S62).

  When the binary determination result of the binary conversion unit 517 is “blank image” (S62: YES), the CPU 51 deletes the BW binary image stored in the RAM 53 from the RAM 53 (S64). Then, the CPU 51 ends the auto-time output process.

  When the result of the binary determination by the binary conversion unit 517 is not “blank image” (S62: NO), the CPU 51 outputs the BW binary image stored in the RAM 53 to an output destination designated in advance ( S63). Then, the auto output process is terminated.

  When the determination result of the color number detection unit 515 is not “BW image” (S61: NO), the multi-value determination by the function of the blank paper determination unit 514 is executed following the determination of the color number detection unit 515. . Then, the CPU 51 determines whether or not the result of the multi-value determination of the blank sheet determination unit 514 is “blank sheet image” (S65).

  When the result of the multi-value determination by the blank page determination unit 514 is “blank page image” (S65: YES), the CPU 51 ends the auto-time output process.

  When the multi-value determination result of the blank page determination unit 514 is not “blank image” (S65: NO), the CPU 51 determines whether or not the determination result of the color number detection unit 515 is “color image”. (S66).

  When the determination result of the color number detection unit 515 is “color image” (S66: YES), the CPU 51 generates a color Jpeg multi-value image by the function of the Jpeg compression unit 516, and the color Jpeg multi-value. The image is output to a predetermined output destination (S68). Then, the CPU 51 ends the auto-time output process.

  When the determination result of the color number detection unit 515 is not “color image” (S66: NO), the CPU 51 generates a gray Jpeg multi-value image by the function of the Jpeg compression unit 516, and the gray Jpeg multi-value image. Are output to an output destination designated in advance (S67). Then, the CPU 51 ends the auto-time output process.

<Manual output processing>

  The flow of the manual output process executed in step S7 shown in FIG. 3 is shown in FIG.

  In the manual output process, the CPU 51 determines whether or not “scan type: BW” is set (S71).

  When “scan type: BW” is set (S71: YES), generation of a BW binary image and binary determination by the function of the binary conversion unit 517 are executed. Further, the generated BW binary image is stored in the RAM 53. Then, the CPU 51 determines whether or not the binary determination result of the binary conversion unit 517 is “blank image” (S72).

  When the binary determination result of the binary conversion unit 517 is “blank image” (S72: YES), the CPU 51 deletes the BW binary image stored in the RAM 53 from the RAM 53 (S74). Then, the CPU 51 ends the manual output process.

  When the result of the binary determination by the binary conversion unit 517 is not “blank paper image” (S72: NO), the CPU 51 outputs the BW binary image stored in the RAM 53 to a predesignated output destination ( S73). Then, the CPU 51 ends the manual output process.

  When “scan type: BW” is not set (S71: NO), multi-value determination by the function of the blank sheet determination unit 514 is executed. Then, the CPU 51 determines whether or not the result of the multi-value determination by the blank sheet determination unit 514 is “blank sheet image” (S75).

  When the result of the multi-value determination by the blank page determination unit 514 is “blank page image” (S75: YES), the CPU 51 ends the manual output process.

  When the result of the multi-value determination by the blank page determination unit 514 is not “blank page image” (S75: NO), the CPU 51 determines whether “scan type: gray” is set (S76).

  When “scan type: gray” is set (S76: YES), the CPU 51 generates a gray Jpeg multi-value image by the function of the Jpeg compression unit 516, and the gray Jpeg multi-value image is designated in advance. To the output destination (S77). Then, the CPU 51 ends the manual output process.

  When “scan type: gray” is not set (S76: NO), the CPU 51 generates a color Jpeg multi-value image by the function of the Jpeg compression unit 516, and the color Jpeg multi-value image is designated in advance. To the output destination (S78). Then, the CPU 51 ends the manual output process.

<Blank paper non-removal processing>

  The flow of blank sheet non-removal processing executed in step S8 shown in FIG. 3 is shown in FIG.

  In the blank sheet non-removal process, the CPU 51 determines whether or not “scan type: auto” is set (S801).

  If “scan type: auto” is set (S801: YES), the CPU 51 determines whether or not the result of determination by the color number detection unit 515 is “BW image” (S802).

  When the determination result of the color number detection unit 515 is not “BW image” (S802: NO), the CPU 51 determines whether or not the determination result of the color number detection unit 515 is “color image” ( S803).

  When the determination result of the color number detection unit 515 is “color image” (S803: YES), the CPU 51 generates a color Jpeg multi-value image by the function of the Jpeg compression unit 516, and the color Jpeg multi-value. The image is output to an output destination designated in advance (S804). Then, the CPU 51 ends the blank sheet non-removal process.

  When the determination result of the color number detection unit 515 is neither “BW image” nor color (S803: NO), the CPU 51 generates a gray Jpeg multi-valued image by the function of the Jpeg compression unit 516, and the gray The Jpeg multi-valued image is output to an output destination designated in advance (S805). Then, the CPU 51 ends the blank sheet non-removal process.

  When the determination result of the color number detection unit 515 is “BW image” (S802: YES), the CPU 51 generates a BW binary image by the function of the binary conversion unit 517, and the BW binary image. Is output to an output destination designated in advance (S806). Then, the CPU 51 ends the blank sheet non-removal process.

  If “scan type: auto” is not set (S801: NO), the CPU 51 determines whether “scan type: color” is set (S807).

  If “scan type: color” is not set (S807: NO), the CPU 51 determines whether “scan type: BW” is set (S808).

  When “scan type: BW” is set (S808: YES), the CPU 51 generates a BW binary image by the function of the binary conversion unit 517, and the BW binary image is designated in advance. The data is output to the output destination (S809). Then, the CPU 51 ends the blank sheet non-removal process.

  When neither “scan type: color” nor BW is set (S808: NO), the CPU 51 generates a gray Jpeg multi-value image by the function of the Jpeg compression unit 516, and the gray Jpeg multi-value image. Is output to an output destination designated in advance (S810). Then, the CPU 51 ends the blank sheet non-removal process.

  When “scan type: color” is set (S807: YES), the CPU 51 generates a color Jpeg multi-value image by the function of the Jpeg compression unit 516, and the color Jpeg multi-value image is designated in advance. To the output destination (S811). Then, the CPU 51 ends the blank paper removal process.

<Binary determination processing (part 1)>

  The flow of the binary determination process by the binary conversion unit 517 is shown in FIG.

  In the binary determination process, the CPU 51 determines whether or not the number of black pixels in the BW binary image is a predetermined threshold, for example, 10 dots or more (S101).

  When the number of dots of black pixels is 10 dots or more (S101: YES), the CPU 51 determines that the BW binary image is not blank, and stores the determination result in the RAM 53 (S102).

  When the number of dots of black pixels is less than 10 (S101: NO), the CPU 51 determines that the BW binary image is blank, and stores the determination result in the RAM 53 (S103).

<Effect>

  As described above, after a multi-value image is acquired by the image acquisition unit 20 and image processing is performed, when an image after image processing is generated, “scan type: auto” or “scan type: BW” is set. If set, binary conversion and binary determination by the binary conversion unit 517 are executed. In binary conversion by the binary conversion unit 517, an image after image processing is converted into a BW binary image by binary conversion by simple binarization. In the binary determination by the binary conversion unit 517, based on the BW binary image, it is determined whether or not the BW binary image is a blank paper image.

  On the other hand, when “scan type: auto”, “scan type: color”, or “scan type: gray” is set, the processing of the Jpeg compression unit 516 and the multi-value determination by the blank sheet determination unit 514 are executed. In the processing of the Jpeg compression unit 516, the image after image processing is converted into a color Jpeg multi-valued image or a gray Jpeg multi-valued image. In the multi-value determination by the blank paper determination unit 514, based on the image after image processing, it is determined whether the image after image processing is a blank paper image.

  Thereby, when the BW binary image is output, the multi-value determination by the blank paper determination unit 514 is not performed, and the binary determination by the binary conversion unit 517 is performed. Further, when a color Jpeg multi-valued image or a gray Jpeg multi-valued image is output, binary determination by the binary conversion unit 517 is not performed, and multi-value determination by the blank paper determination unit 514 is performed.

  When it is determined that the BW binary image is a blank image, the BW binary image is not output. Therefore, the result of the binary determination by the binary determination unit 517 coincides with the result that the image is not output by the blank paper removal function. On the other hand, when it is determined that the BW binary image is not a blank image, the BW binary image is output. Therefore, the result of the binary determination by the binary conversion unit 517 and the result that the BW binary image is output coincide.

  If it is determined by multi-value determination that the image processed image is a blank image, no image is output. For this reason, the result of the multi-value determination and the result that the image is not output due to the blank sheet removal match. On the other hand, if it is determined in the multi-value determination that the image after image processing is not a blank image, a color Jpeg multi-value image or a gray Jpeg multi-value image is output. Therefore, the result of the multi-value determination of the blank paper determination unit by the multi-value determination process and the result that the multi-value image is output coincide.

  Therefore, an output result that is consistent with the blank sheet determination result can be expected.

  When “scan type: auto” is set, the generation of the color Jpeg multi-valued image or the gray Jpeg multi-valued image is determined by the multi-value determination result by the blank paper determination unit 514 and the determination by the color number detection unit 515. It is executed after the result of. Therefore, it is possible to reduce the possibility that the storage area of the RAM 53 is compressed because the color Jpeg multi-valued image and the gray Jpeg multi-valued image are unnecessarily generated and stored in the RAM 53.

  In the binary determination by the binary conversion unit 517, the control unit 50 determines that the BW binary image is not a blank image when the number of pixels converted into black pixels by binary conversion is, for example, 10 dots or more. .

  According to this configuration, by counting the number of pixels converted into black pixels by binary conversion and comparing the counted number of pixels with a threshold (for example, 10 dots), the BW binary image is a blank image. It can be easily determined whether or not there is. Further, since the binary determination method is simple, it is possible to expect a high speed binary determination process.

<Binary determination processing (part 2)>

  When the BW binary image generated by the function of the binary conversion unit 517 is compressed and output, the binary determination process by the binary conversion unit 517 may be the process shown in FIG.

  As the number of white pixels included in the BW binary image increases, the compression rate of the BW binary image increases and the size of the BW binary image after compression decreases. Therefore, the CPU 51 determines whether or not the file size of the BW binary image is a predetermined threshold, for example, 1 kbyte or more (S201).

  When the file size of the BW binary image is 1 kbyte or more (S201: YES), the CPU 51 determines that the BW binary image is not a blank image, and stores the determination result in the RAM 53 (S202).

  When the file size of the BW binary image is smaller than 1 kbyte (S201: NO), the CPU 51 determines that the BW binary image is a blank image, and stores the determination result in the RAM 53 (S203).

  The control unit 50 stores the BW binary image compressed by the compression process in the RAM 53. In the binary determination process, if the size of the BW binary image compressed by the compression process is 1 kbyte or more, it is determined that the BW binary image is not a blank image.

  According to this configuration, it is possible to easily determine whether or not the BW binary image is a blank image by comparing the size of the compressed BW binary image with a threshold (for example, 1 kbyte). . Further, since the binary determination method is simple, it is possible to expect a high speed binary determination process.

<Modification>

  As mentioned above, although embodiment of this invention was described, this invention can also be implemented with another form.

  In the above-described embodiment, the case where the CPU 51 executes each process has been described. However, the ASIC 55 may execute each process, or the CPU 51 and the ASIC 55 may execute each process in cooperation. The control unit 50 may include a plurality of CPUs, and the plurality of CPUs may cooperate to execute each process.

  Further, a program for each process executed by the CPU 51 of the MFP 1 may be installed in a PC (computer) connected to the Internet, and the same process as each process executed by the CPU 51 may be executed on the PC.

Furthermore, it is not limited to a PC connected to the Internet.
A program for each process executed by the CPU 51 of the MFP 1 is installed on a PC (not shown) connected to the MFP 1 via the Network, and the same process as the process executed by the CPU 51 is executed on the PC. May be.

  In the above-described embodiment, the MFP 1 having the printing function by the image forming unit 10 and the reading function by the image reading unit 20 is taken up as an example of the image processing device. However, the image processing device may be a reading device having a reading function. A single-function device may be used.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1 MFP
20 Image Reading Unit 50 Control Unit 514 Blank Paper Determination Unit 516 Jpeg Compression Unit 517 Binary Conversion Unit

Claims (6)

An acquisition unit that acquires a multi-valued image as an acquired image;
A control unit,
The controller is
A binary conversion process for converting the acquired image into a binary image;
Based on the binary image obtained by the binary conversion process, a binary determination process for determining whether the binary image is a blank paper image;
If it is determined in the binary determination process that the binary image obtained by the binary conversion process is a blank image, the binary image is not output, and the binary determination process does not output the binary image. An image processing apparatus that executes a binary output process for outputting a binary image when it is determined that the binary image obtained by the value conversion process is not a blank image. The image processing apparatus according to claim 1,
The controller is
In the binary determination process, when the number of pixels converted into black pixels by the binary conversion process is equal to or greater than a predetermined threshold, it is determined that the binary image obtained by the binary conversion process is not a blank image. , Image processing device. The image processing apparatus according to claim 1, wherein:
The controller is
Performing a compression process to compress the binary image obtained by the binary conversion process;
In the binary determination process, when the size of the binary image compressed by the compression process is equal to or larger than a predetermined threshold, the binary image obtained by the binary conversion process is determined not to be a blank image. Processing equipment. The image processing apparatus according to any one of claims 1 to 3,
The controller is
Multi-value determination processing for determining whether the acquired image is a blank image based on the acquired image;
Multi-value output processing to output a multi-value image;
A multi-value conversion process for converting the acquired image into a multi-value image output in the multi-value output process,
In the multi-value output process, if the acquired image is determined to be a blank image in the multi-value determination process, no image is output, and the acquired image is not a blank image in the multi-value determination process. An image processing device that outputs a multi-valued image obtained by the multi-value conversion process. The image processing apparatus according to claim 4,
The controller is
An image processing apparatus that determines whether or not the acquired image is a blank image based on luminance component data of the acquired image in the multilevel determination process. In a computer connected to an image processing apparatus including an acquisition unit that acquires a multi-valued image as an acquired image,
A binary conversion process for converting the acquired image into a binary image;
Based on the binary image obtained by the binary conversion process, a binary determination process for determining whether the binary image is a blank paper image;
If it is determined in the binary determination process that the binary image obtained by the binary conversion process is a blank image, the binary image is not output, and the binary determination process does not output the binary image. An image processing program for executing a binary output process for outputting a binary image when it is determined that the binary image obtained by the value conversion process is not a blank image.

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