JP4559173B2 - Image processing device - Google Patents

Description

  The present invention relates to an image processing apparatus that reads a document as image data, performs image processing on the image data, and performs copying. In particular, the present invention relates to an image processing apparatus that copies the same document a plurality of times.

  Conventionally, in a color copying machine, an operator can arbitrarily set whether to perform color copying processing or black-and-white copying processing according to a document to be copied. In addition, there are cases where color originals and black and white originals are mixed as originals for color printing and color hard copy, but in the case of black and white originals, high quality output can be obtained by performing black and white copy processing. Further, since image formation is performed only for the K (Black) version of a black and white document, the output time can be shortened compared to the case of image formation using the CMYK (Cyan, Magenta, Yellow, Black) version. As such a color copying machine, there is a type that automatically performs color / monochrome determination for determining whether a document is a color document or a monochrome document, and automatically switches the operation mode according to the determination result. (For example, refer to Patent Document 1).

  Furthermore, a color copier equipped with a function capable of storing read image data temporarily in a memory so that even if a print image is defective, the document can be re-output without being read again. (For example, refer to Patent Document 2).

JP 63-107274 A JP-A-9-191379

  However, it is inconvenient in operation for the user to set an operation mode suitable for a document one by one according to the type of document. According to the technique described in Patent Document 1, the operation mode can be switched according to the type of document. For example, when the output is not normally terminated due to a paper jam at the time of printout, the document is again printed. It took time and effort to read.

  In addition, as in the technique described in Patent Document 2, even when the image data is stored in the memory, after re-outputting, the image data is read from the memory, and then the operation mode corresponding to the type of the read document is set again. Judgment had to be made and the processing efficiency could not be improved.

  In order to solve the above-described problems caused by the prior art, the present invention can reproduce an original without re-determining the operation mode according to the type of the original without reducing the operability of the operator at the time of re-output. An object is to provide a processing apparatus.

In order to solve the above-described problems and achieve the object, an image processing apparatus of the present invention determines a reading unit that converts a document into read image data and outputs the image, and attributes of the image data output from the reading unit Attribute determining means, control means for associating the image data with the attribute data of the image data determined by the attribute determining means, the image data associated with the control means, and a storage for storing the attribute data means and, receiving means for receiving said output means accumulated the image data in the storage means to output based on the attribute data, the request for the output when performing an output of image data stored before Symbol storage means again When, read out the said image data request has been accepted for output and the attribute data by the receiving means from said storage means Switches the color conversion parameter based on the attribute data read out from said memory means, into a color space dependent on the image data to an output device, a second color conversion means for outputting to the output device, the The attribute determination means calculates a maximum color difference of each pixel in a predetermined unit block, calculates the number of pixels having the maximum color difference larger than a predetermined first threshold as the number of chromatic pixels, and Pixel block determining means for determining that the unit block is a chromatic block when the number of chromatic pixels is larger than a predetermined second threshold; and the number of chromatic blocks on the document determined by the pixel block determining means. When the count value exceeds a predetermined comparison value, the original is a color original, and when the count value is less than the predetermined comparison value, the original is a monochrome original. Characterized in that it comprises a color image determining unit determines that it is, the.

  According to the present invention, since the attributes of the read image data are stored in the storage means in association with the image data, the same document can be copied without re-determining the operation mode corresponding to the document type at the time of re-output. Can do. Whether the original is a color original or a black and white original, the attributes of the original can be determined, and a copy corresponding to the attribute can be made. When image data and attribute data are read from the storage means, the image data can be converted into a color space unique to the printer and copied. In addition, since the operation mode for performing color copy processing or monochrome copy processing can be automatically switched, a high-quality output image can be obtained without imposing a burden on the operator.

The image processing apparatus of the present invention further includes a first color conversion unit that converts the image data output from the reading unit into image data in a color space that does not depend on an input device, and outputs the image data to the control unit. Features.

According to the present invention , image data can be converted into image data in a color space that does not depend on the device characteristics of the input device, and the color-converted image data can be stored in the storage means and copied.

  According to the image processing apparatus of the present invention, it is automatically determined whether the original is a color original or a black-and-white original, and the determination result is stored in the storage unit together with the image data, thereby burdening the operator. There is an effect that it is possible to obtain a high-quality output image without spending and to improve the processing efficiency at the time of re-output.

Exemplary embodiments of an image processing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

(Functional configuration of image processing apparatus)
First, the contents of the image processing apparatus according to the embodiment of the present invention will be described. Here, a full-color image processing apparatus that employs the sRGB storage method will be described as an example.

  FIG. 1 is a block diagram showing an example of a functional configuration of an image processing apparatus 100 according to an embodiment of the present invention.

  The image processing apparatus 100 includes an engine unit 101 and a printer controller unit 102.

  The engine unit 101 performs image input / output of the image processing apparatus 100 around a reading unit (input device) 111 and an image forming unit (output device) 124. A reading unit 111 scans a document such as a photograph or document set on a document table, reads image information on the document as an R, G, B (Red, Green, Blue) color 8-bit electrical signal, and performs scanner correction. Output to the unit 112 and the document attribute determination unit 114.

  The scanner correction unit 112 performs color conversion processing, filtering processing, and scaling processing on the RGB format image data output from the reading unit 111, and outputs the processed image data to the fixed-length multi-value compressor 113. .

  Here, details of processing performed on the image data by the scanner correction unit 112 will be described with reference to FIG.

  FIG. 2 is a diagram illustrating the configuration of the scanner correction unit 112. The scanner correction unit 112 includes a color conversion unit (LUT) (first color conversion unit) 201, a filter processing unit 202, and a scaling processing unit 203.

  The color conversion unit 201 converts RGB format image data output from the reading unit 111 into an sRGB color space, and outputs the sRGB color space to the filter processing unit 202. For this color space conversion, for example, a memory-up interpolation method using a multi-dimensional look-up table (LUT) is used (see, for example, JP-A-2002-1885804). Here, the lookup table divides the input color space into a plurality of unit interpolation cubic groups, selects a unit interpolation cube including input color data, and outputs output values corresponding to a plurality of vertices of the selected unit interpolation cube. It is a table.

  The filter processing unit 202 includes various filters, performs filter processing on the image data output from the color conversion unit 201, and outputs the filtered image data to the scaling processing unit 203. The scaling processing unit 203 performs scaling processing on the filtered image data output from the filter processing unit 202 and outputs the processed image data to the fixed-length multi-value compressor 113.

  Returning to the description of FIG. 1, the fixed-length multi-value compressor 113 converts the 8-bit sRGB image data for each color output from the scanner correction unit 112 into n-bit (n <= 8) sRGB image data for each color. Convert to

  Based on the RGB format image data output from the reading unit 111, the document attribute determination unit 114 performs color / monochrome determination for determining whether the document is a color document or a monochrome document.

  The fixed length multi-value expander 121 decodes sRGB image data of n bits (n <= 8) for each color into sRGB image data of 8 bits for each color. The fixed-length multi-value compressor 113, the document attribute determination unit 114, and the fixed-length multi-value expander 121 are each connected to the general-purpose bus 115.

  The printer correction unit 122 performs color conversion processing, printer γ correction, and halftone processing on the image data decoded by the fixed-length multi-value expander 121 and outputs the result to the GAVD 123.

  Details of processing performed on the image data by the printer correction unit 122 will be described with reference to FIGS.

  3 and 4 are diagrams showing the configuration of the printer correction unit 122. FIG. The printer correction unit 122 includes a color conversion unit (LUT) (second color conversion unit) 301, a printer γ correction unit 302, and a halftone processing unit 303.

  A color conversion unit 301 converts the 8-bit sRGB image data of each color decoded by the fixed-length multi-value expander 121 into an 8-bit CMYK color signal or K signal of each color according to the attribute data, and a printer γ correction unit It outputs to 302. That is, when color output is performed, color conversion is performed into CMYK color signals as shown in FIG. 3, and when monochrome output is performed, color conversion is performed into K signals as shown in FIG. Then, the printer γ correction unit 302 performs printer γ correction on the color signal after color conversion, the halftone processing unit 303 performs halftone processing, and outputs the result to the GAVD 123.

  Returning to the description of FIG. 1, the GAVD (gate array video driver) 123 controls the LD (laser diode) of the image forming unit 124 based on the image data output from the printer correction unit 122. Output a signal. The image forming unit 124 forms an image with an optical scanning device using an LD, and outputs the image onto a transfer sheet. This LD is controlled by an LD control signal output from the GAVD 123. The engine controller 110 is connected to the scanner correction unit 112 and the printer correction unit 122 via the general-purpose bus 115, and controls the scanner correction unit 112 and the printer correction unit 122.

  Next, the configuration of the printer controller unit 102 will be described. The printer controller unit 102 is configured around a printer controller (control unit) 116. The printer controller 116 is connected to a general-purpose bus 115, a hard disk (HDD) 120, and a NIC (Network Interface Card) 125, and inputs / outputs image data and attribute data to / from them. Here, the attribute data is an attribute determination signal for determining whether the above-described document is a color document or a monochrome document. In addition, the printer controller 116 has independent semiconductor memories 117 to 119 for each of R, G, and B colors.

  The printer controller 116 associates image data and its attribute data and stores them in the hard disk 120 as needed. The NIC 125 can exchange data with an external PC or the server 126.

(Operation of image processing device)
Next, the operation of the image processing apparatus according to the embodiment of the present invention will be described with reference to FIG. The arrows shown in the figure indicate the flow of data during copying. When an operator sets an original on the reading unit 111 and presses a print button provided on an operation panel (not shown), the content of the original is read by the reading unit 111. The read contents are supplied to the scanner correction unit 112 and the document attribute determination unit 114 as 8-bit image data of each color separated into R, G, and B colors.

  Next, as shown in FIG. 2, the RGB format image data supplied from the reading unit 111 is converted into the sRGB color space via the color conversion unit 201, and the filter processing unit 202 and the scaling processing unit 203 are further processed. These are sequentially supplied to the fixed length multi-value compressor 113.

  Returning to FIG. 1, in the fixed-length multi-value compressor 113, the sRGB image data of each color 8 bits after the scaling process is converted into sRGB image data of each color n bits (n <= 8), and is sent via the general-purpose bus 115. To the printer controller 116. By compressing the image data, the amount of image data stored in the hard disk 120 is reduced.

  The document attribute determination unit 114 performs color / monochrome determination based on the RGB format image data supplied from the reading unit 111 to determine whether the document is a color document or a monochrome document. The attribute data is supplied to the printer controller 116 via the general-purpose bus 115.

  Details of the operation of the document attribute determination unit 114 will be described with reference to FIGS.

  FIG. 5 is a diagram illustrating a configuration of the document attribute determination unit 114. The document attribute determination unit 114 includes a color pixel block determination unit 501 and a color image determination unit 502. The color pixel block determination unit 501 performs chromatic block determination based on the RGB format image data supplied from the reading unit 111 and supplies the determination signal to the chromatic image determination unit 502.

  Here, the operation of the color pixel block determination unit 501 will be described with reference to FIG.

  FIG. 6 is a diagram showing a matrix of maximum color differences of unit blocks. In the color pixel block determination unit 501, the RGB difference maximum value ΔRGB = d [i, j] (maximum color difference) (d [i, j] = max {rij, gij, bij} −min {rij, gij, bij }; I, j = 0, 1, 2, 3) is calculated. Next, the number of pixels in which the maximum color difference d [i, j] is larger than the threshold Th1 defined in the unit block of 4 lines × 4 pixels, that is, the number of chromatic pixels | C | is counted for 16 pixels in the unit block. (C = {d [i, j] | d [i, j]> Th1}). When the number of chromatic pixels | C | is larger than a predetermined threshold Th2, this unit block is determined as a chromatic block, and the chromatic block signal SG2 = H is supplied to the chromatic image determination unit 502.

  Next, the operation of the color image determination unit 502 will be described with reference to FIG.

  FIG. 7 is a diagram illustrating a configuration of the chromatic image determination unit 502. The color image determination unit 502 includes a determination counter 701 and a determination comparator 702. The determination counter 701 counts the number of blocks of the chromatic block signal SG2 = H supplied from the color pixel block determination unit 501, and the determination comparator 702 compares the count value of the determination counter 701 with the comparison value, and the count value is compared. When the value is exceeded, the layer coloring signal SG1 = H is supplied to the printer controller 116 via the general-purpose bus 115. That is, it is determined that a document with SG1 = H is a color document, and a document with SG1 = L is a monochrome document.

  Returning to FIG. 1, the printer controller 116 associates the sRGB image data of n bits (n <= 8) for each color supplied from the fixed-length multi-value compressor 113 with the attribute data supplied from the document attribute determination unit 114. And stored in an independent semiconductor memory (memory B117, memory G118, and memory R119) for each color. As described above, by associating the image data with the attribute data, the attribute data can be read out together only by designating the image data. The image data and attribute data associated by the printer controller 116 are written to the hard disk 120 as needed. This is to avoid rereading the document again and to perform electronic sorting even when the paper is jammed at the time of printout by the image processing apparatus 100 and the output does not end normally.

  Next, when outputting image data, each color n-bit (n <= 8) sRGB image data and attribute data in the hard disk 120 are once developed in a semiconductor memory (memory B117, memory G118, and memory R119). Are supplied to the fixed-length multi-value expander 121 through the general-purpose bus 115. In the fixed-length multi-value expander 121, sRGB image data of each color n bits (n <= 8) is decoded again into sRGB image data of each color 8 bits, and supplied to the printer correction unit 122 together with attribute data.

  As shown in FIGS. 3 and 4, in the printer correction unit 122, an 8-bit sRGB color signal of each color is converted into an 8-bit CMYK color signal or K signal of each color via the color conversion unit 301 in accordance with the attribute data. Color conversion is performed. The parameters of the printer correction unit 122 at this time are automatically selected as the optimum look-up table parameters in the color conversion unit 301 based on the attribute data supplied together with the 8-bit sRGB image data for each color. Since the parameters are automatically selected in this way, high-quality output can be obtained without imposing a burden on the operator.

  Next, printer γ correction is performed on the 8-bit CMYK color signal or K signal of each color, and halftone processing in accordance with the GAVD 123 and the image forming unit 124 is performed. Here, the printer γ correction unit 302 may also perform correction by automatically selecting a correction parameter based on the attribute data.

  Returning to FIG. 1, the image data that has been processed by the printer correction unit 122 is converted into an LD control signal by the GAVD 123 and output to the transfer paper by the image forming unit 124.

  Next, the operation when copying image data stored in the hard disk 120 will be described. For example: 1. When reprinting a document when paper is jammed at the time of printout and output is not completed normally. 2. When electronic sorting is performed by rearranging a plurality of image data; This is a copying process for outputting data stored in the hard disk 120 when necessary.

  When an operator requests copying of image data stored in the hard disk 120 by using an operation panel (not shown), each color n-bit (n <= 8) sRGB image data and its attribute data in the hard disk 120 are once stored in a semiconductor memory ( Memory B117, memory G118, and memory R119), and then supplied to the fixed-length multi-value expander 121 through the general-purpose bus 115. Since the image data and its attribute data can be read from the hard disk 120 in this way, there is no need to perform color / monochrome determination again. In the fixed-length multi-value expander 121, the n-bit (n <= 8) sRGB image data of each color is decoded into sRGB image data of 8 bits for each color and supplied to the printer correction unit 122 together with the attribute data.

  As shown in FIGS. 3 and 4, in the printer correction unit 122, an 8-bit sRGB color signal for each color is converted into an 8-bit color for each color via the color conversion unit 301 in accordance with the attribute data read from the hard disk 120. Color conversion to CMYK color signals or K signals is performed. The parameters of the printer correction unit 122 at this time are automatically selected as the optimum look-up table parameters in the color conversion unit 301 based on the attribute data supplied together with the 8-bit sRGB image data for each color. Next, printer γ correction is performed on the 8-bit CMYK color signal or K signal of each color, and halftone processing in accordance with the GAVD 123 and the image forming unit 124 is performed.

  Returning to FIG. 1, the image data that has been processed by the printer correction unit 122 is converted into an LD control signal by the GAVD 123 and output to the transfer paper by the image forming unit 124.

  In this embodiment, sRGB, which is recognized as a standard color space on a PC as a color space at the time of storage and has a good affinity such as color matching with the PC and its peripheral devices, is used. Space may be used. However, it is easy to exchange data between devices and applications by using some defined color space.

  As described above, according to the image processing apparatus, the image processing method, and the image processing program of the present invention, it is automatically determined whether a document is a color document or a monochrome document, and the determination result is determined as image data. In addition, by accumulating in the storage means, it is possible to obtain a high-quality output image without imposing a burden on the operator, and to improve the processing efficiency at the time of re-output.

  The image processing method described in the present embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. This program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. The program may be a transmission medium that can be distributed via a network such as the Internet.

  As described above, the image processing apparatus, the image processing method, and the image processing program according to the present invention are useful for image processing for copying the same document a plurality of times, and are particularly connected to a digital copying machine, a facsimile, a scanner, and a printer. Suitable for equipment that

1 is a block diagram showing an example of a functional configuration of an image processing apparatus 100 according to an embodiment of the present invention. 2 is a diagram illustrating a configuration of a scanner correction unit 112. FIG. 2 is a diagram illustrating a configuration of a printer correction unit 122. FIG. 2 is a diagram illustrating a configuration of a printer correction unit 122. FIG. 3 is a diagram illustrating a configuration of a document attribute determination unit 114. FIG. It is a figure which shows the matrix of the maximum color difference of a unit block. FIG. 6 is a diagram illustrating a configuration of a color image determination unit 502.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Engine part 102 Printer controller part 111 Reading unit 112 Scanner correction part 113 Fixed length multi-value compressor 114 Original attribute determination part 115 General-purpose bus 116 Printer controller 117-119 Memory 120 Hard disk 121 Fixed length multi-value expander 122 Printer correction part 201 301 color converter (LUT)
501 color pixel block determination unit 502 chromatic image determination unit 701 determination counter 702 determination comparator

Claims (2)

Scanning means for converting a document into scanned image data and outputting the scanned data;
Attribute determination means for determining an attribute of the image data output from the reading means;
Control means for associating the image data with the attribute data of the image data determined by the attribute determination means;
Storage means for accumulating the image data associated with the control means and the attribute data;
Output means for outputting the image data stored in the storage means based on the attribute data ;
A receiving means for receiving a request for the output when performing an output of image data stored before term memory unit again,
Reading out said image data request has been accepted for output and the attribute data by the receiving unit from the storage unit, switching the color conversion parameter based on the attribute data read out from said storage means, the image data A second color conversion means for converting to a color space depending on the output device and outputting to the output device ,
The attribute determining unit calculates the maximum color difference of each pixel in a predetermined unit block, calculates the number of pixels having the maximum color difference larger than a predetermined first threshold as the chromatic pixel number, Pixel block determination means for determining the unit block as a chromatic block when the number is larger than a predetermined second threshold;
The number of chromatic blocks on the original determined by the pixel block determining means is counted, and when the count value exceeds a predetermined comparison value, the original is a color original, and the count value is a predetermined comparison. A color image determining means for determining that the original is a black and white original when the value is less than
An image processing apparatus comprising:   2. The image according to claim 1, further comprising a first color conversion unit that converts the image data output from the reading unit into image data in a color space independent of an input device and outputs the image data to the control unit. Processing equipment.

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