JP2013223084A - Image processing apparatus, image forming apparatus including the same, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform appropriate spatial filter processing to image data without increasing the scale of a circuit.SOLUTION: An image processing apparatus includes: a first magnification unit 35 that converts the size of image data into a predetermined size, when an instruction to process the image data as image data of a picture is input from an operation panel 21; and a spatial filter unit 44 that processes the image data processed by the first magnification unit 35 with a filter in a mask size that is set on the basis of said predetermined size.

Description

  The present invention relates to an image processing apparatus that performs image processing on an input image, an image forming apparatus including the image processing apparatus, a program, and a recording medium.

  Currently, image forming apparatuses such as copiers, multi-function machines, and printers using an electrophotographic process or an inkjet method are widely used. This type of image forming apparatus is capable of reproducing color images with high image quality along with the progress of digital image processing technology, and has been commercialized as a full-color digital copying machine or multifunction machine.

  The original image copied by the above-described image forming apparatus is a character, a halftone dot photo, a line drawing, a photo (a photo composed of continuous tone areas such as a photographic paper photo), or a mixture of them. Therefore, in the image forming apparatus, it is necessary to perform image processing suitable for the type of document image in order to obtain a good reproduction image from such a document.

  For example, in Patent Document 1, the following image processing is performed. First, an input image is identified (region separation) into three types: a character image, a halftone image, and a continuous tone image other than the character image and the halftone image. Next, edge extraction is performed on the input image, the extraction result is converted into an edge amount with reference to the region separation result, and edge enhancement processing (spatial filter processing) is performed based on the obtained edge amount. Do.

  In this edge enhancement processing, strong edge enhancement processing is performed on a character image, and weak edge enhancement processing is performed on a halftone image. Further, for a continuous tone region, edge enhancement processing is performed with an intermediate strength between edge enhancement processing for a character image and edge enhancement processing for a halftone image. Alternatively, smoothing processing is performed instead of performing edge enhancement processing. In this smoothing process, the weakest smoothing process is performed on the character image, and the strong smoothing process is performed on the continuous tone image and the halftone image. Thereby, it is possible to improve the resolution of characters on halftone dots and suppress moire, improve the resolution of character images, and improve the sharpness of silver halide photographs and the like by mixed originals.

Japanese Patent Laid-Open No. 2001-274997 (published on October 5, 2001)

  In the technique described in Patent Document 1, the order of performing the spatial filter process and the scaling process is not considered. For example, when scaling processing is performed after spatial filter processing, it is necessary to set a spatial filter for each mask size corresponding to the size of each input image data (number of pixels in the main scanning direction and sub-scanning direction). Specifically, when the size of the input image data is large, it is necessary to increase the mask size of the spatial filter. This is because if the size of the input image data is large and the spatial filter process is performed with a small mask size, the image area to be processed becomes small, and the effect of the spatial filter process appears only in the high-frequency component portion of the image. It is.

  However, when a spatial filter is prepared for each mask size corresponding to the size of the input image data, there is a problem that the number of types of spatial filters to be held increases and the circuit scale increases. In addition, when a filter having a large mask size (for example, 9 × 9 pixels) is used, the number of line memories to be held increases, so that there is a problem that the circuit scale also increases.

  Therefore, the present invention provides an image processing apparatus capable of appropriately performing spatial filter processing on input image data without causing an increase in circuit scale, an image forming apparatus provided with the image processing apparatus, a program, and a recording medium It is an object.

  In order to solve the above-described problems, an image processing apparatus according to the present invention is provided when an input device operated by a user and an instruction for processing input image data as image data of a photograph are input from the input device. A scaling unit that converts the input image data into image data of a predetermined size set as the size of the image data of the photo, and the image data processed by the scaling unit is based on the predetermined size And a spatial filter unit that performs a spatial filter process using a filter having a mask size set in this manner.

  The image processing method of the invention converts the input image data into image data of a predetermined size set as the size of the photo image data based on an instruction to process the input image data as photo image data. And a spatial filter step of performing a spatial filter process on the image data processed in the scaling step with a filter having a mask size set based on the predetermined size. Yes.

  According to the above configuration, the scaling unit (in the scaling step) corresponds to the input image data having a predetermined size, for example, the L size when an instruction to process the input image data as photo image data is input. To image data of the number of pixels to be converted. The spatial filter unit (in the spatial filter step) has a mask size (for example, 7 × 7 pixel size) set based on the predetermined size for the image data processed in the scaling unit (scaling step) Spatial filter processing is performed using the filter.

  As a result, the input image data processed as the image data of the photograph is unified to a predetermined size before the spatial filter processing, so the filter used for the spatial filter processing of the input image data is unified of the input image data. It is only necessary to prepare a size, that is, a mask size set based on a predetermined size. Therefore, the circuit scale of the spatial filter unit (spatial filter used for the spatial filter process) can be reduced.

  On the other hand, if the input image data is not scaled to a predetermined size before the spatial filter processing, each input is performed in order to perform optimal spatial filter processing on the input image data of each size. A filter having a mask size corresponding to the size of the image data must be prepared. In this case, the circuit scale of the spatial filter unit (spatial filter used for the spatial filter process) increases. On the other hand, when the spatial filtering process is performed with a filter having a smaller mask size than the mask size capable of appropriately processing the input image data without unifying the input image data into a predetermined size, the input image data has a high frequency. The effect of the spatial filter processing is exhibited only for the components.

  In addition, according to the configuration of the present invention, the predetermined size can be set to a relatively small size, so that the mask of a large size (for example, 9 × 9 pixel size) is used in the spatial filter unit (spatial filter used in the spatial filter process). It is not necessary to have. Therefore, the capacity of the line memory used for the spatial filter processing can be reduced, and the circuit scale can be reduced accordingly.

  The image processing apparatus includes a notifying unit for notifying a user, an automatic document type determining unit for determining the type of input image data, and the input image data being printed or printed by the automatic document type determining unit. A control unit that causes the notifying unit to perform an operation for prompting the input device to select whether to process the input image data as image data of a photo when it is determined to be a photo. It is good also as composition which has.

  According to the above configuration, the control unit determines whether or not to process the input image data as the image data of the photo when the input image data is determined to be a photographic paper photo or a printed photo by the automatic document type determination unit. The notification means, for example, a display unit, performs an operation for prompting the user to select an item using the input device.

  Thus, when the instruction for processing the input image data as the image data of the photograph is input from the input device in response to the notification from the notification means, the operations of the scaling unit and the spatial filter unit described above are performed.

  Therefore, even when the user does not grasp the processing content in the image processing apparatus for the input image data that is the image data of the photograph, the preferable processing as the image data of the photograph for the input image data Can be selected.

  The image processing apparatus includes a document type automatic determination unit that determines the type of input image data, and the spatial filter unit determines that the input image data is a photographic paper photograph by the document type automatic determination unit. When the input image data is subjected to a spatial filter process having an emphasis characteristic and a smoothing characteristic, and the input image data is determined to be a printed photograph, the input image data is smoothed. It is good also as a structure which performs the spatial filter process which has a characteristic.

  According to the above configuration, the spatial filter unit is a space having an emphasis characteristic and a smoothing characteristic with respect to the input image data when the original type automatic determination unit determines that the input image data is a photographic paper photograph. Apply filtering. In addition, when it is determined that the input image data is a printed photograph, the input image data is subjected to a spatial filter process having a smoothing characteristic.

  As a result, the optimum spatial filter processing can be applied to the photographic paper photograph and the printed photograph.

  An image forming apparatus according to the present invention includes any one of the above-described image processing apparatuses, a sublimation type printing apparatus that performs printing based on image data processed as photographic image data by the image processing apparatus, and the image processing And an electrophotographic printing apparatus that performs printing based on image data processed as image data other than photographic image data by the apparatus.

  According to the above configuration, it is possible to obtain optimum print images based on image data of photographs and image data other than photographs.

  According to the configuration of the present invention, the input image data to be processed as photo image data is unified to a predetermined size before the spatial filter processing. Therefore, the filter used for the spatial filter processing of the input image data is the input image data. It is only necessary to prepare a uniform size of data, that is, a mask size set based on a predetermined size. As a result, it is possible to appropriately perform spatial filter processing on the input image data without causing an increase in circuit scale.

1 is a block diagram illustrating a schematic configuration of an image forming apparatus according to an exemplary embodiment. FIG. 2A is an explanatory diagram showing a filter used when the document type of the input image data is a photographic paper photograph in the spatial filter unit shown in FIG. 1, and FIG. FIG. 4 is an explanatory diagram showing a filter used when the original type of input image data is a printed photograph in the image section. 3 is a flowchart showing main operations when the image processing apparatus shown in FIG. 1 performs photo printing and printing other than photo printing. FIG. 2 is a block diagram illustrating a configuration in the case where photographic printing is performed in the image forming apparatus illustrated in FIG. 1. It is a block diagram which shows the structure of the software processing part shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

[Prerequisites]
The image processing apparatus 12 (see FIG. 1) according to the embodiment of the present invention, when performing image processing for photo printing, for example, on input image data of a photo, The size is unified to a predetermined size. This is to prevent the circuit scale of the spatial filter unit 44 (see FIG. 1) from increasing. That is, when the image data of a photograph is scaled at an arbitrary scaling factor and can be converted into an arbitrary size, a filter corresponding to the image data of an arbitrary size is provided in the spatial filter unit 44 in order to prevent image quality degradation. It is necessary to prepare. In this case, the circuit scale of the spatial filter unit 44 increases.

  The photograph includes a photographic paper photograph having a continuous gradation (a silver salt photograph or a photograph printed on glossy paper by an ink jet method) and a printed photograph (halftone dot photograph). The output form of the image data from the image processing apparatus 12 is copying or image transmission. The predetermined size is a photo size L plate size, 2L plate size, or the like. In the following description, the predetermined size is described as the L plate size. The size of the image data is determined by the number of pixels in the main scanning direction and the sub-scanning direction. The size of the photo includes L version, 2L version, four-cut size, etc., but L size is often used. Therefore, it is preferable from the viewpoint of versatility and price to set the L plate size to a predetermined size.

  The above processing for the input image data of the photo may be performed when photo printing is selected on the operation panel 21 (see FIG. 1), for example. Photo printing in this case may be performed by a sublimation printer or a thermal transfer printer instead of an electrophotographic printer. Further, as a process before performing photo printing, for example, when the input image data is determined to be a photographic paper photo manuscript or a printed photo manuscript by the manuscript type automatic discrimination unit 34 (see FIG. 1), for example, display on the operation panel 21 The unit 21a (see FIG. 1) may prompt the user to select whether or not to perform photo printing. Note that the number of pixels and the resolution of the input image data may be anything.

[Description of Image Forming Apparatus]
Hereinafter, a case where the configuration of the present invention is applied to an image forming apparatus will be described. FIG. 1 is a block diagram illustrating a schematic configuration of an image forming apparatus according to the present embodiment. Note that the processing flow indicated by the arrows in FIG. 1 is for the case where the image forming apparatus 1 performs printing other than photographic printing. On the other hand, the processing flow indicated by the arrows in FIG. 4 is for the case where the image forming apparatus 1 performs photo printing.

  The image forming apparatus 1 is a digital color multi-function peripheral that executes a selected mode when one of a copy mode, a print mode, a facsimile transmission mode, a facsimile reception mode, and an image transmission mode is selected. .

  As shown in FIG. 1, the image forming apparatus 1 includes an image input device 11, an image processing device 12, a first image output device 13, a second image output device 14, a reception device 15, a transmission device 16, a storage device 17, and a control. Unit 18, data input device 19, software processing unit 20, and operation panel (input device) 21.

  The image input device 11 reads a document and generates image data in the copy mode, the facsimile transmission mode, and the image transmission mode. Specifically, the image input device 11 includes a scanner unit having a CCD (Charge Coupled Device), and converts the light reflected from the document into an electrical signal (analog image signal) that is color-separated into RGB. The electric signal is input to the image processing device 12.

  The image processing apparatus 12 performs image processing on image data (image signal), and includes an ASIC (Application Specific Integrated Circuit) as an integrated circuit. The image processing apparatus 12 includes an A / D (analog / digital) conversion unit 31, a shading correction unit 32, an input processing unit 33, a document type automatic discrimination unit 34, a first scaling unit (magnification unit) 35, and a compression unit 36. , Region separation processing unit 37, region separation signal compression unit 38, decoding unit 39, region separation signal decoding unit 40, image quality adjustment unit 41, color correction unit 42, black generation / under color removal unit 43, spatial filter unit 44, A 2 zoom unit 45, an output tone correction unit 46, and a halftone generation unit 47 are provided. The processing contents of each unit included in the image processing apparatus 12 will be described later.

  The image processing device 12 performs image processing on the image data sent from the image input device 11 in the copy mode, the facsimile transmission mode, and the image transmission mode. In the print mode, image processing is performed on the image data temporarily stored in the storage device 17 from the software processing unit 20. In the facsimile reception mode, image processing is performed on image data received from an external device.

  Further, the image processing device 12 transmits the image data subjected to the image processing to the image output device (the first image output device 13 or the second image output device 14) in the copy mode, the print mode, and the facsimile reception mode. In the facsimile transmission mode, the image data subjected to image processing is transmitted to the transmission device 16. Further, in the scan to e-mail mode of the image transmission mode, the image data subjected to image processing is transmitted to a mail processing unit (not shown). In the scan to ftp mode, image data subjected to image processing is transmitted to a predetermined folder, and in the scan to usb mode, image data subjected to image processing is transmitted to a predetermined USB memory.

  The first image output device 13 is an electrophotographic or inkjet color printer, and prints (forms) an image of image data sent from the image processing device 12 on a recording medium (for example, paper). The second image output device 14 is a sublimation printer, and performs a printing operation when photo printing is selected by a user operation on the operation panel 21. In the present embodiment, “printing” means any one of printing in the print mode, printing in the copy mode, and printing in the facsimile reception mode.

  The receiving device 15 is connected to a telephone line or the Internet, and receives image data from an external device by facsimile communication. The transmission device 16 is connected to a telephone line or the Internet, and transmits image data input by the image input device 11 to an external device by facsimile communication. The storage device 17 is, for example, a hard disk device for temporarily storing image data handled by the image processing device 12.

  The control unit 18 includes a computer including a processor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), and comprehensively controls various hardware included in the image forming apparatus 1. The control unit 18 also has a function of controlling data transfer between the respective hardware provided in the image forming apparatus 1.

  The data input device 19 is a device for inputting image data to be printed in the print mode. The data input device 19 has an interface for connecting a data storage device such as a USB (Universal Serial Bus) memory or an SD (Secure Digital Memory Card) card, acquires image data stored in the data storage device, and The image data is transferred to the software processing unit 20.

  The software processing unit 20 is a device that performs image processing by software on the image data sent from the data input device 19, and is configured by, for example, a computer equipped with a CPU.

  The operation panel 21 is an input device for various instructions from the user to the image forming apparatus 1 (image processing apparatus 12). The operation panel 21 includes, for example, a touch panel and includes a display unit (notification unit) 21a that displays various types of information.

  In the image processing device 12, the A / D conversion unit 31 converts the color image signal (RGB analog signal) sent from the image input device 11 into digital image data (RGB digital signal). The shading correction unit 32 performs processing for removing various distortions generated in the illumination system, the imaging system, and the imaging system of the image input device 11 on the image data sent from the A / D conversion unit 31. The input processing unit 33 performs gradation conversion processing such as γ correction processing on each of the RGB image data sent from the shading correction unit 32.

  The first scaling unit 35 is a predetermined setting in which the input image data is set as the size of photo image data as data size conversion processing when photo printing is selected by a user operation on the operation panel 21. Convert to image data of size (L size). Therefore, when photo printing is selected, the size of the input image data is unified to a predetermined size. On the other hand, when photo printing is not selected, the process for the input image data is not performed.

  The document type automatic determination unit 34 determines the type of document based on the RGB signal image data that has been subjected to gradation conversion processing by the input correction unit 33. Here, the types of originals to be judged include character originals, photographic paper photographs (continuous tone) originals, printed photo originals, character printed photo originals in which characters and printed photographs are mixed, and characters and photographic paper photographs. It is a mixed text photographic paper photo manuscript. Further, the document type automatic determination unit 34 is an automatic color determination process (ACS: determination process for determining whether a document read by the image input device 11 is a color document or a monochrome document based on input image data. Perform Auto Color Selection. Further, as the determination process (determination process), it is also possible to determine whether or not the original is a blank original (whether or not it is a plain original).

  The compression unit 36 encodes the image data (RGB signal) sent from the document type automatic discrimination unit 34. Note that the encoding is performed based on, for example, a JPEG (Joint Photographic Experts Group) system.

  Based on the RGB image data, the region separation processing unit 37 determines, for each pixel of the input image, what image region the pixel is classified into, and generates a region separation signal indicating the determination result. Here, the image regions discriminated by the region separation processing unit 37 include a black character region, a color character region, a halftone dot region, and the like. Note that the region separation processing may be in a form in which the image region is determined for each block including a plurality of pixels, instead of determining the image region for each pixel.

  The region separation signal compression unit 38 performs a compression process on the region separation signal generated for each pixel. The compression processing in the region separation signal compression unit 38 is performed based on, for example, the MMR (Modified Modified Reed) method or the MR (Modified Reed) method which is a lossless compression method.

  The control unit 18 temporarily stores the encoded code (encoded image data) output from the compression unit 36 and the region separation signal code (compressed region separation signal) output from the region separation signal compression unit 38. It is stored in the device 17 and managed as filing data. In addition, when a copy output operation is instructed, the control unit 18 reads the encoded code and the region separation signal code corresponding to the encoded code from the storage device 17, and the encoded code is sent to the decoding unit 39. The region separation signal code is delivered to the region separation signal decoding unit 40.

  The control unit 18 registers the storage address or data name of the encoded code and the storage address of the region separation signal code in association with each other in the management table. That is, the control unit 18 controls reading or writing of the encoded code and the region separation signal code using the management table.

  The decoding unit 39 performs a decoding process on the encoded code, and expands the encoded code into RGB image data. The region separation signal decoding unit 40 performs a decoding process on the region separation signal code. The decoded region separation signal is input to the black generation / undercolor removal unit 43, the spatial filter unit 44, and the halftone generation unit 47. In the black generation / undercolor removal unit 43, the spatial filter unit 44, and the halftone generation unit, the image processing content is switched according to the type of the image area.

  The image quality adjustment unit 41 detects the background of the RGB image data sent from the decoding unit 39 and performs background removal correction. Further, the image quality adjustment unit 41 adjusts RGB balance (color adjustment, overall color adjustment such as reddish blue), brightness, and vividness based on setting information input from the operation panel 21 by the user.

  When the full color mode is selected, the color correction unit 42 performs color correction processing for converting RGB image data into CMY image data, and performs processing for improving color reproducibility on the image data.

  When the full color mode is selected, the black generation / under color removal unit 43 generates black (K) image data from the CMY image data output from the color correction unit 42 (black generation processing). Further, new CMY image data is generated by subtracting black (K) image data from the original CMY image data. Accordingly, when the full color mode is selected, the CMY image data is converted into CMYK four-color image data by the black generation / under color removal unit 43 as shown in FIG.

  The second scaling unit 45 is a scaling command (information indicating the magnification of the print image) that is input by a user operation on the operation panel 21 when photo printing is not selected by the user operation on the operation panel 21. Based on the above, the image is enlarged or reduced. On the other hand, when photo printing is selected, the above process is through.

  The spatial filter unit 44 applies spatial filter processing (enhancement processing, smoothing) to the CMYK or CMY image data output from the black generation / undercolor removal unit 43 based on a region separation signal (region identification signal). Processing, emphasis and smoothing mixed filter processing, etc.). That is, the spatial filter unit 44 performs different image processing for each image region based on the region separation signal.

  The output tone correction unit 46 performs output γ correction processing for outputting the image data output from the spatial filter unit 44 to a recording medium such as paper.

  The halftone generation unit 47 uses the error diffusion method or the dither method to perform gradation reproduction processing (intermediate) necessary for printing an image in the image output device (the first image output device 13 or the second image output device 14). Key generation processing). The CMYK or CMY image data output from the halftone generation unit 47 is input to the image output device (the first image output device 13 and the second image output device 14). The image output devices (the first image output device 13 and the second image output device 14) print an image of the image data on a recording medium (for example, paper).

[Configuration example of automatic document type determination unit]
The document type automatic determination unit 34 may determine the document type by a method described in, for example, Japanese Patent Application Laid-Open No. 2002-232708. Below, the discrimination method described in the said patent document is demonstrated.

  (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) The calculated maximum density difference is compared with the maximum density difference threshold, and the calculated total density busyness is compared with the total density busyness threshold. As a result of this comparison, 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 pixel of interest 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) For a pixel determined to belong to the background / photographic paper photograph area, it is determined that the pixel of interest is a background pixel when the maximum density difference <the background / photographic paper photograph determination threshold value is satisfied. When the above conditions are not satisfied, it is determined that the pixel is a photographic paper photograph (continuous tone area) pixel.

  (6) For a pixel determined to belong to the character / halftone dot region, the target pixel is a character pixel when the condition of the sum density density complexity <maximum density difference is multiplied by the character / halftone determination threshold value is satisfied. Is determined. When the above condition is not satisfied, it is determined that the pixel is 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 the respective count values and predetermined ground areas, a photographic paper photograph area, a halftone dot area, and a character. The type of the entire document is determined by comparing the threshold value for the area. For example, when the detection accuracy is high in the order of characters, halftone dots, and photographic paper photographs, if the character area ratio is 30% or more of the total number of pixels, it is determined that the document is a character document. If the ratio of the halftone area is 20% or more of the total number of pixels, it is determined that the original is a halftone original (printed photo original). When the ratio of the photographic paper photograph area is 10% or more of the total number of pixels, it is determined that the photographic paper photograph original. Further, if the ratio of the character area and the ratio of the halftone dot area are equal to or greater than the threshold values, respectively, it is determined that the character / halftone original (character-printed photo original).

In the above configuration, the operation of the image forming apparatus 1 will be described below.
The document image data read by the image input device 11 is input to the image processing device 12 as input image data, and is processed in each part of the image processing device 12 as described above. Thereafter, the image data (input image data) processed by the image processing device 12 is input to the first image output device 13 or the second image output device 14 and printed on paper.

  Next, operations when performing photo printing in the main part of the image forming apparatus 1 (image processing apparatus 12) and printing other than photo printing will be described.

(Operation of the automatic document type discriminator)
The document type automatic determination unit 34 determines whether the input image data is a photographic paper photo or a print photo when photo printing is selected by a user operation on the operation panel 21 as the document type determining operation. To do. On the other hand, when photo printing is not selected, it is determined whether the input image data is a character original, a printed photo original, a photographic paper photo original, a character / print photo original, or a character / print paper photo original.

(Operation of the first zoom unit)
When photo printing is selected by a user operation on the operation panel 21, the first scaling unit 35 converts input image data into L-size pixels (output resolution: 300 dpi, 1051 × as data size conversion processing). (1500 pixels). On the other hand, if photo printing is not selected, the data size conversion process is not performed (the process is through).

  For the data size conversion process, a known interpolation method such as a two-arrest neighbor method, a bilinear method, or a bicubic method can be used.

  Here, the nearest neighbor method uses the value of an existing pixel closest to the pixel to be interpolated or having a predetermined positional relationship with the pixel to be interpolated as the value of the interpolated pixel.

  In the bilinear method, an average of values weighted in a form proportional to the distance between four existing pixels surrounding a pixel to be interpolated is obtained, and that value is used as the interpolation pixel.

  In the bicubic method, an average of values weighted in a form proportional to the distance between four existing pixels surrounding a pixel to be interpolated is obtained, and that value is used as the interpolation pixel.

(Operation of the spatial filter section)
When photo printing is selected by a user operation on the operation panel 21, the spatial filter unit 44 selects each space depending on whether the document type of the input image data is a photographic paper photo or a printed photo. Perform filtering.

  Specifically, based on the document type determination result of the document type automatic determination unit 34, when the document type of the input image data is a photographic paper photograph, a filter having enhancement characteristics and smoothing characteristics for the input image data Is used to perform enhancement processing and smoothing processing. The enhancement process is performed in order to clarify that the image data (input image data) obtained by scanning with the image input device 11 is blurred. The smoothing process is performed to prevent noise because noise is noticeable only by the enhancement process. For the above enhancement processing and smoothing processing, for example, a filter having a filter coefficient shown in FIG.

  The spatial filter unit 44 also includes a filter having a smoothing characteristic for the input image data when the document type of the input image data is a printed photograph based on the document type determination result of the document type automatic determination unit 34. To smooth the surface. This smoothing process is performed so as to obtain a continuous tone component by blurring the halftone dot component. For the smoothing process, for example, a filter having a filter coefficient shown in FIG.

  Each of the filters shown in FIGS. 2A and 2B has a mask size of 7 × 7 pixels, for example. The mask size of the filter is determined to be a size that can smooth the halftone dot component and the noise during document scanning in the frequency space.

  On the other hand, the spatial filter unit 44 performs enhancement processing and smoothing processing on the input image data based on the region separation signal when photo printing is not selected.

  Next, the main operation of the image forming apparatus 1 will be described based on the flowchart of FIG. FIG. 3 is a flowchart showing main operations when the image processing apparatus 12 performs photo printing and printing other than photo printing.

  When printing is performed by the image forming apparatus 1, an image of a document is read by the image input device 11, and image data corresponding to the document image is input from the image input device 11 to the image processing device 12. Alternatively, image data is input from the external device to the image processing device 12.

  Image data (input image data) input from the image input device 11 to the image processing device 12 includes an A / D conversion unit 31, a shading correction unit 32, an input processing unit 33, a document type automatic discrimination unit 34, and a first scaling. The data is temporarily stored in the storage device 17 via the unit 35 and the compression unit 36. Thereafter, the data is read out from the storage device 17, and the decoding unit 39, the image quality adjustment unit 41, the color correction unit 42, the black generation / under color removal unit 43, the spatial filter unit 44, the second scaling unit 45, and the output tone correction unit 46 and the halftone generation unit 47, for example, output to the first image output device 13 or the second image output device 14 and printed.

  The region separation signal generated by the region separation processing unit 37 is temporarily stored in the storage device 17 via the region separation signal compression unit 38. Thereafter, the data is read from the storage device 17 and supplied to the black generation / undercolor removal unit 43, the spatial filter unit 44, and the halftone generation unit 47 via the region separation signal decoding unit 40.

  In the first scaling unit 35, when photo printing of the input image data is selected by the user's operation on the operation panel 21 (S11), the input image data is converted to the L size (predetermined size) as the data size conversion process. ) (Scaling) (S12). Note that, as described above, the L plate size is a size set in advance in the image forming apparatus 1 as a print size when performing photo printing.

  Next, based on the document type determination result of the document type automatic determination unit 34, the spatial filter unit 44 sets the input image data to a predetermined size when the document type of the input image data is a photographic paper photograph (silver salt photograph) (S13). Enhancement processing and smoothing processing are performed on the converted input image data (S14).

  On the other hand, the spatial filter unit 44, based on the document type determination result of the document type automatic determination unit 34, when the document type of the input image data is not a photographic paper photograph (silver salt photograph) (when it is a printed photograph) ( S13) Smoothing processing is performed on the input image data converted to a predetermined size (S15).

  Thereafter, as shown in FIG. 4, the image data is output from the image processing device 12 to the second image output device 14 that is a sublimation printer, and is printed as an L-size photograph by the second image output device 14 ( S16).

  On the other hand, when photographic printing is not selected in S11, the image processing apparatus 12 performs an image corresponding to the printing by the first image output apparatus 13 which is an electrophotographic or inkjet color printer for the input image data. Processing is performed (S17).

  In the process in this case, when the scaling process to an arbitrary size is specified for the enlargement / reduction of the image by the user's operation on the operation panel 21, the second scaling unit 45 performs the process on the image data. , Perform scaling to any specified size.

  Thereafter, as shown in FIG. 1, the image data is output from the image processing device 12 to the first image output device 13 which is an electrophotographic or inkjet color printer, and is printed by the first image output device 13. (S18).

  Next, in the case of performing photo printing, the image forming apparatus 1 (image processing apparatus) due to a difference in input form of input image data to the image processing apparatus 12 and a difference in output form of processed image data from the image processing apparatus 12 The difference in the operation content of 12) will be described.

[When processing image data read by an image input device]
The image forming apparatus 1 that performs the processing in this case has the form shown in FIG.

(1) In the case of copying operation: Since photo printing is selected by a user operation on the operation panel 21, it is known that the input image data is a photographic paper photo or a printed photo. Therefore, the region separation processing unit 37 does not operate.
Since printing is performed by the second image output device (sublimation printer) 14, the processing in the black generation / undercolor removal unit 43 and the halftone generation unit 47 is through (no processing is performed).
The color correction unit 42 selects a color correction table for the second image output device (sublimation printer) 14 and performs color correction processing (RGB signal → R′G′B ′ signal).

(2) In the case of image transmission or filing (when transmitting or filing image data of a predetermined size)
The processes of the area separation processing unit 37, the black generation / undercolor removal unit 43, and the halftone generation unit 47 are through as in the case of the copy operation.
The color correction unit 42 converts the image data into sRGB used in many displays. The image data converted into sRGB is attached to an e-mail by a mail processing unit (not shown) and transmitted to the other party via the network. Alternatively, the image data converted into sRGB is filed in the storage device 17 including a hard disk device, for example.

[When processing image data held by an external device]
In this case, image data held by a digital camera as an external device or image data held by a USB memory or an SD card is processed. In this case, the processing of the document type automatic discrimination unit 34, the first scaling unit 35, and the spatial filter unit 44 in the image processing device 12 may be performed by the software processing unit 20 instead of the image processing device 12.

  In this case, as shown in FIG. 5, the software processing unit 20 performs the automatic document type discrimination unit 51, the scaling unit 52, and the spatial filter for the automatic document type discrimination unit 34, the first scaling unit 35, and the spatial filter unit 44. A unit 53 is provided. FIG. 5 is a block diagram showing a configuration of the software processing unit 20 shown in FIG.

  The software processing unit 20 may include a color correction unit 54 and an output gradation correction unit 55 in addition to the above configuration. In this case, processing that should be performed by the image processing apparatus 12 can be performed by the software processing unit 20.

  For processing of image data held by the external device, a digital camera, a USB memory, an SD card or the like as an external device is connected to the data input device 19, and photo printing is selected as print processing by a user operation on the operation panel 21. To be implemented.

(1) In the case of printing operation: The image data read from the external device by the data input device 19 is a document type determination process by the document type automatic determination unit 51 of the software processing unit 20, a scaling process by the scaling unit 52, After the spatial filter processing based on the document type discrimination result by the spatial filter unit 53 is performed, the spatial filter unit 53 temporarily stores it in the storage device 17.
Next, the image data stored in the storage device 17 is read at a predetermined timing, and the image quality toning process (implemented as necessary) by the image quality adjustment unit 41, the color correction process by the color correction unit 42, and After the output tone correction processing by the output tone correction unit 46 is performed, printing is performed by the second image output device (sublimation printer) 14.

(2) In the case of filing operation This operation is performed when filing instead of printing is selected as the output form of image data by a user operation on the operation panel 21. For example, this is processing when image data is read from a USB memory and a USB memory is designated as a storage destination. Note that the number of pixels of the image data can be acquired from the header of the image data.
The operation until the image data read from the external device is processed by the software processing unit 20 and stored in the storage device 17 is the same as that in the printing operation.
The image data read from the storage device 17 is subjected to image quality tonality processing (implemented as necessary) by the image quality adjustment unit 41 and color correction processing (converted to sRGB) by the color correction unit 42 (output gradation) The processing of the correction unit 46 is through) and is stored in the designated USB memory.

  As described above, the image forming apparatus 1 according to the present embodiment performs a scaling process on input image data into image data of a specific size (for example, L size of a photo) when photo printing is instructed. Spatial filter processing is performed. As a result, when performing photo printing, the size of the image data to be subjected to the spatial filter processing is unified to a specific size. Therefore, the filter mask size required for the spatial filter processing is limited to one type, and the types of filters to be prepared can be reduced. As a result, it is possible to appropriately perform spatial filter processing on the input image without causing an increase in circuit scale.

  In the above embodiment, the first scaling unit 35 scales the input image data of a photograph to a predetermined size (L size). However, this predetermined size is not limited to the case where it is fixed, and for example, it may be configured to be switchable to another size (for example, 2L size). In this case, the spatial filter unit 44 only needs to include a filter having a mask size corresponding to the sizes of the two image data. Even in this case, the circuit scale of the spatial filter unit 44 can be reduced as compared with the case where the input image data of the photograph is scaled to an arbitrary size.

[Description of program / recording medium]
Each block of the image processing apparatus 12 may be configured by hardware logic, or may be realized by software using a CPU as follows.

  That is, the image processing apparatus 12 includes a CPU (central processing unit) that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, and a RAM (random access memory) that expands the program. And a storage device (recording medium) such as a memory for storing the program and various data. An object of the present invention is a recording medium on which a program code (execution format program, intermediate code program, source program) of a control program of the image processing apparatus 12 which is software for realizing the functions described above is recorded so as to be readable by a computer. This can also be achieved by supplying the image processing apparatus 12 and reading and executing the program code recorded on the recording medium by the computer (or CPU or MPU).

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  Further, the image processing apparatus 12 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention 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 present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in the embodiments are also included. It is included in the technical scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used in an inexpensive copying machine and multifunction machine that include an electrophotographic or ink jet printer and a sublimation printer and that can perform photo printing.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 11 Image input apparatus 12 Image processing apparatus 13 1st image output apparatus (Electrophotographic type or inkjet type printing apparatus)
14 Second image output device (sublimation printing device)
17 Storage Device 18 Control Unit 20 Software Processing Unit 21 Operation Panel (Input Device)
21a Display section (notification means)
34 Document type automatic discrimination unit 35 First scaling unit (scaling unit)
37 Region separation processing unit 44 Spatial filter unit 45 Second scaling unit 51 Automatic document type discrimination unit 52 Scaling unit 53 Spatial filter unit

Claims (7)

An input device operated by a user;
Scaling that converts the input image data into image data of a predetermined size set as the size of the photo image data when an instruction to process the input image data as photo image data is input from the input device And
An image processing apparatus comprising: a spatial filter unit that performs a spatial filter process on the image data processed by the scaling unit using a filter having a mask size set based on the predetermined size . A notification means for notifying the user;
A document type automatic discrimination unit for discriminating the type of input image data;
When the input image data is determined to be a photographic paper photograph or a printed photograph by the document type automatic determination unit, the input device selects whether to process the input image data as image data of a photograph. The image processing apparatus according to claim 1, further comprising: a control unit that causes the notifying unit to perform an operation for prompting the user. A document type automatic discrimination unit for discriminating the type of input image data is provided.
The spatial filter unit performs a spatial filter process having an emphasis characteristic and a smoothing characteristic on the input image data when the input image data is determined to be a photographic paper photograph by the document type automatic determination unit. The image processing apparatus according to claim 1, wherein when the input image data is determined to be a printed photograph, a spatial filter process having a smoothing characteristic is applied to the input image data. The image processing apparatus according to any one of claims 1 to 3,
A sublimation type printing apparatus that performs printing based on image data processed as image data of a photograph in the image processing apparatus;
An image forming apparatus comprising: an electrophotographic printing apparatus that performs printing based on image data processed as image data other than photographic image data by the image processing apparatus. Based on an instruction to process the input image data as photo image data, a scaling step for converting the input image data into image data of a predetermined size set as the size of the photo image data;
A spatial filter step of performing a spatial filter process on the image data processed in the scaling step with a filter having a mask size set based on the predetermined size. .   The program for functioning a computer as said each part of the image processing apparatus of any one of Claim 1 to 4.   A computer-readable recording medium on which the program according to claim 6 is recorded.

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