Patent Publication Number: US-2011051169-A1

Title: Image Processing Device

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to an image processing device. 
     2. Related Art 
     An ordinary copying machine carries out image processing for scan data in various ways so as to produce output data and to make a copy, as disclosed in, e.g., JP-A-2007-266783. Such a copying machine carries out similar image processing for scan data regardless of a type of a scanned document. 
     Upon copying an ink jet output document, however, the ordinary copying machine can cause blurring in a conspicuous manner in some cases. 
     SUMMARY 
     An advantage of some aspects of the invention is that blurring caused to a copy of an ink jet output document can be made inconspicuous. 
     According to an aspect of the invention, an image processing device includes an input section to which scan data is input, a text identifying section which identifies whether the scan data is text document-based, an output format identifying section which identifies whether the scan data is ink jet output-based upon the text identifying section identifying the scan data as being text document-based, and an image processing section which carries out different kinds of image processing on the scan data in accordance with a result identified by the output format identifying section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  schematically shows a configuration of an image processing device of an embodiment of the invention. 
         FIG. 2  shows a hardware configuration of a block type identifying circuit  107  of the embodiment of the invention. 
         FIG. 3  is a flowchart for explaining a block type identifying process. 
         FIG. 4A  shows an exemplary ink jet output text document. 
         FIG. 4B  shows an exemplary laser output text document. 
         FIG. 4C  shows an enlarged exemplary ink jet output block. 
         FIG. 4D  shows an enlarged exemplary laser output block. 
         FIG. 5A  shows an exemplary method for image processing. 
         FIG. 5B  shows another exemplary method for image processing. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     An exemplary embodiment of the invention will be explained with reference to the drawings as follows. 
       FIG. 1  schematically shows a configuration of an image processing device  100  to which the embodiment of the invention is applied. 
     The image processing device  100  is, e.g., a copying machine. The image processing device  100  scans a document fixed on paper, etc. so as to produce printing data or an electronic file in a particular format. 
     As shown in  FIG. 1 , the image processing device  100  has a CPU  101 , a scanner engine  102 , a RAM  103 , a memory controller  104 , a DMA (Direct Memory Access) section  105 , a scanner image processing circuit  106 , a block type identifying circuit  107 , a copy image processing circuit  108 , a printing data producing circuit  109  and a printing engine  110 . The configuration of the image processing device  100  is not limited to the above as a matter of course. The scanner engine  102  corresponds to an input section. The block type identifying circuit  107  corresponds to a text identifying section and an output format identifying section. The copy image processing circuit  108  and the printing data producing circuit  109  correspond to an image processing section. The printing engine  110  corresponds to a printing section. 
     The CPU  101  is an arithmetic device which implements various functions of the image processing device  100  by controlling other units. The CPU  101  implements various processes by loading the RAM  103  with proper programs stored in a memory such as a ROM (not shown) and running the programs. 
     The CPU  101  scans a document by, e.g., controlling the scanner engine  102 . Further, the CPU  101  performs a process for identifying a document type and various kinds of image processing on scan data (input image data) of the document output from the scanner engine  102  by controlling the scanner image processing circuit  106 , the block type identifying circuit  107 , the copy image processing circuit  108  and the printing data producing circuit  109 . 
     For the document type identifying process, the CPU  101  sets a horizontal edge level HL, a vertical edge level VL and a brightness level BL, which will be described later, to the block type identifying circuit  107 . Further, the CPU  101  divides scan data (image data on which the scanner image processing circuit  106  have performed various kinds of image processing) of one page into a particular number of blocks, and transfers the scan data to the block type identifying circuit  107  on a block-by-block basis. Then, the CPU  101  obtains from the block type identifying circuit  107  the total number of a block type (the total number of blocks for each of the block types) identified for each of the blocks (“text and ink jet output block” A1, “text and non-ink jet output block” B1, “non-text block” C1). Moreover, the CPU  101  identifies a document type (“text and ink jet output document” A2, “text and non-ink jet output document” B2, “non-text document” C2) of every page on the basis of the obtained total number of each of the block types (A1, B1, C1). 
     The text block described here is a block including a text (e.g., a block in which the number of white pixels is greater than a certain threshold). The non-text block is a block including a picture, a figure, etc. (e.g., a block in which the number of white pixels is smaller than a certain threshold). Further, the ink jet output block is a block printed by means of ink jet printing (e.g., a block in which a ratio of the number of pixels on a horizontal edge to the number of pixels on a vertical edge is close to one). The non-ink jet output block is a block printed by means of laser printing, etc. (e.g., a block in which a ratio of the number of pixels on a horizontal edge to the number of pixels on a vertical edge is biased). 
     Further, the “text and ink jet output document” A2 is a document including a text and printed by means of ink jet printing (e.g., a document for which the total number of the blocks of the block type A1 is greatest in one page). Further, the “text and non-ink jet output document” B2 is a document including a text and printed by means of laser printing, etc. (e.g., a document for which the total number of the blocks of the block type B1 is greatest in one page). Further, the “non-text document” C2 is a page including a picture, a figure, etc. (e.g., a document for which the total number of the blocks of the block type C1 is greatest in one page). 
     Further, the CPU  101  carries out printing by controlling the printing engine  110 . Further, the CPU  101  produces an electronic file on the basis of the scan data on which various kinds of image processing have been performed. 
     Various programs and data are stored in the RAM  103 . Image data on which the scanner image processing circuit  106  have performed image processing, image data on which the copy image processing circuit  108  have performed image processing (color conversion, smoothing, edge stressing, etc.), an electronic file produced by the CPU  101 , e.g., are stored in the RAM  103 . 
     The memory controller  104  exchanges data to and from the RAM  103  (a reading process, a writing process) as directed by the respective units (the CPU  101 , the DMA section  105 ). 
     The DMA section  105  is controlled by the scanner image processing circuit  106 , the block type identifying circuit  107 , the copy image processing circuit  108  and the printing data producing circuit  109  individually, so that data can be transferred between each of the units ( 106 - 109 ) and the RAM  103  without being controlled by the CPU  101 . 
     The scanner engine  102  is a unit which reads a document and outputs digitized image data (e.g., RGB image data). The scanner engine  102  has, e.g., an ADF (Auto Document Feeder), a light source, a carriage, a motor for scanning, a CCD line sensor, an AFE (Analog Front End), etc. 
     The scanner engine  102  irradiates every page (every sheet) of a document while letting the ADF transport the document, so as to guide light reflected by the document to the CCD line sensor provided with filters of red (R), green (G) and blue (B). Then, the scanner engine  102  converts analog data of the respective RGB colors which have been read into digital signals, and outputs the digital signals to the scanner image processing circuit  106  as image data having gradation values of the respective RGB colors for each of the pixels. 
     The scanner image processing circuit  106  is a circuit which performs various kinds of image processing on the image data output from the scanner engine  102 . The scanner image processing circuit  106  receives image data of every page of the document, and performs, e.g., a shading correction process, an inter-lines correction process, a scaling up/down process, etc. Then, the scanner image processing circuit  106  stores the image data on which the various kinds of image processing have been performed in the RAM  103  via the DMA section  105  and the memory controller  104 . 
     The block type identifying circuit  107  identifies the block type (A1, B1, C1) of each of the blocks into which the scan data (the image data on which the scanner image processing circuit  106  has performed various kinds of image processing) has been divided. 
     The block type identifying circuit  107  will be explained in more detail with reference to  FIG. 2 .  FIG. 2  shows a hardware configuration of the block type identifying circuit  107  to which the embodiment of the invention is applied. 
     As shown in  FIG. 2 , the block type identifying circuit  107  has a register interface (I/F)  170 , a smoothing filter  171 , a horizontal edge detecting filter  172 , a vertical edge detecting filter  173 , a brightness converting circuit  174 , a horizontal edge pixel counter  175 , a vertical edge pixel counter  176 , a white pixel counter  177 , a block type distinguishing circuit  178  and a block type counter  179 . 
     The register I/F  170  sets a specified horizontal edge level HL to the horizontal edge pixel counter  175  as requested by the CPU  101 . The horizontal edge level HL described here is a threshold for identifying whether each of pixels in one page (in one block) is an edge pixel in the horizontal direction. Further, the register I/F  170  sets a specified vertical edge level VL to the vertical edge pixel counter  176 . The vertical edge level VL described here is a threshold for identifying whether each of pixels in one page (in one block) is an edge pixel in the vertical direction. 
     Further, the register I/F  170  sets a specified brightness level BL to the white pixel counter  177  as requested by the CPU  101 . The brightness level BL described here is a threshold for identifying whether each of pixels in one page (in one block) is a white pixel. 
     The register I/F  170  obtains from the block type counter  179  the total number of blocks included in one page for each of the block types (described later) as requested by the CPU  101 , and outputs the obtained respective total number of blocks to the CPU  101 . 
     Further, the register I/F  170  activates the DMA section  105  (the DMA connected to the block type identifying circuit  107 ), and transfers image data (pixel data) of one page on a block-by-block basis without being controlled by the CPU  101 . 
     The smoothing filter  171  is a circuit which receives image data (pixel data) output from the RAM  103  via the DMA section  105  on a block-by-block basis, and carries out a smoothing filtering operation for each of the pixels. Owing to the smoothing filtering operation, a noise component included in the image data of each of the input pages can be less possibly detected as a false edge pixel. The smoothing filter  171  outputs the filtered image data (pixel data) to the horizontal edge detecting filter  172 , the vertical edge detecting filter  173  and the brightness converting circuit  174 . 
     The horizontal edge detecting filter  172  is a circuit which performs a filtering operation for detecting an edge in the horizontal direction for each of the pixels and outputs an edge value. As the filter, e.g., a Sobel filter or a Prewitt filter which finds a difference between each of the pixels and its adjacent pixel can be employed. The horizontal edge detecting filter  172  provides the horizontal edge pixel counter  175  with an edge value of the filtered pixel data. 
     The vertical edge detecting filter  173  is a circuit which performs a filtering operation for detecting an edge in the vertical direction for each of the pixels and outputs an edge value. As the filter, e.g., a Sobel filter or a Prewitt filter which finds a difference between each of the pixels and its adjacent pixel can be employed. The vertical edge detecting filter  173  provides the vertical edge pixel counter  176  with an edge value of the filtered pixel data. 
     The brightness converting circuit  174  is a circuit which converts an RGB gradation value of each of the input pixel data into a brightness value L indicating brightness. The brightness converting circuit  174  calculates the brightness value L by carrying out an operation in accordance with a proper converting equation (e.g., a converting equation: L=0.2989×R+0.5866×G+0.1145×B). The brightness converting circuit  174  provides the white pixel counter  177  with the calculated brightness value L. 
     The horizontal edge pixel counter  175  is a circuit which counts the number of edge pixels in the horizontal direction. The horizontal edge pixel counter  175  identifies whether the edge value of each of the pixels output from the horizontal edge detecting filter  172  is greater than a certain threshold (the horizontal edge level HL being set). Further, the horizontal edge pixel counter  175  counts the pixels of the edge values greater than the threshold as horizontal edge pixels. Then, the horizontal edge pixel counter  175  provides the block type distinguishing circuit  178  with the number of the horizontal edge pixels included in one block. 
     The vertical edge pixel counter  176  is a circuit which counts the number of edge pixels in the vertical direction. The vertical edge pixel counter  176  identifies whether the edge value of each of the pixels output from the vertical edge detecting filter  173  is greater than a certain threshold (the vertical edge level VL being set). Further, the vertical edge pixel counter  176  counts the pixels of the edge values greater than the threshold as vertical edge pixels. Then, the vertical edge pixel counter  176  provides the block type distinguishing circuit  178  with the number of the vertical edge pixels included in one block. 
     The white pixel counter  177  is a circuit which counts the number of white pixels. The white pixel counter  177  identifies whether the brightness value of each of the pixels output from the brightness converting circuit  174  is greater than a certain threshold (the brightness level EL being set). Further, the white pixel counter  177  counts the pixels of the brightness values greater than the threshold as white pixels. Then, the white pixel counter  177  provides the block type distinguishing circuit  178  with the number of the white pixels included in one block. 
     The block type distinguishing circuit  178  is a circuit which distinguishes the block type (A1, B1, C1) of the image data (pixel data) of one block. 
     The block type distinguishing circuit  178  identifies whether the number of the horizontal edge pixels output from the horizontal edge pixel counter  175  or the number of the vertical edge pixels output from the vertical edge pixel counter  176  is greater than a certain threshold (e.g., the number of pixels corresponding to ten percent of the number of all the pixels forming one block). The block type distinguishing circuit  178  identifies as well whether the number of the white pixels output from the white pixel counter  177  is greater than a certain threshold (e.g., the number of pixels corresponding to 30 percent of the number of all the pixels forming one block). Then, upon identifying one of the number of the horizontal edge pixels and the number of the vertical edge pixels as being greater than the threshold and identifying the number of the white pixels as being greater than the threshold, the block type distinguishing circuit  178  identifies the relevant block as a text block. Meanwhile, upon identifying both the number of the horizontal edge pixels and the number of the vertical edge pixels as being smaller than the threshold, or identifying the number of the white pixels as being smaller than the threshold, the block type distinguishing circuit  178  identifies the relevant block as a “non-text block” C1. 
     Upon identifying the relevant block as a text block, the block type distinguishing circuit  178  identifies whether a ratio R of the number of the horizontal edge pixels output from the horizontal edge pixel counter  175  to the number of the vertical edge pixels output from the vertical edge pixel counter  176  (e.g., the number of the horizontal edge pixels/the number of the vertical edge pixels) is close to one (e.g., 0.8&lt;ratio R&lt;1.2) or biased (e.g., ratio R≦0.8, ratio R≧1.2). Then, upon identifying the ratio R as being close to one, the block type distinguishing circuit  178  regards the pixels included in one block as having random edge directions, and identifies the relevant block as a “text and ink jet output block” A1. Meanwhile, upon identifying the ratio R as being biased, the block type distinguishing circuit  178  regards the pixels included in one block as having a definite direction, and identifies the relevant block as a “text and non-ink jet output block” B1. 
     Then, the block type distinguishing circuit  178  distinguishes a block type of every block similarly as described above, and provides the block type counter  179  with a signal (data) indicating the identified block type (A1, B1, C1). 
     The block type counter  179  is a circuit which counts the number of blocks belonging to each of the block types (A1, B1, C1) in one page. The block type counter  179  identifies the block type output from the block type distinguishing circuit  178  for every block, and counts the number of blocks belonging to a same block type. Then, the block type counter  179  individually stores the total number of the blocks belonging to the “text and ink jet output block” A1, the total number of the blocks belonging to the “text and non-ink jet output block” B1, the total number of the blocks belonging to the “non-text block” C1 in memory, and outputs the respective total numbers as requested by the register I/F  170 . 
     The configuration of the block type identifying circuit  107  is not limited to the above as a matter of course. The block type identifying circuit  107 , e.g., can lack the smoothing filter  171 . 
     Return to  FIG. 1  for continuing the explanation. The copy image processing circuit  108  is a circuit which performs various kinds of image processing on the image data output from the scanner image processing circuit  106  for copying the image data. The copy image processing circuit  108  obtains from the RAM  103  the image data of the respective pages on which various kinds of image processing have been performed by the scanner image processing circuit  106 , and performs, e.g., a color conversion process, a smoothing process, an edge stressing process, etc. Then, the copy image processing circuit  108  stores the image data on which the various kinds of image processing have been performed in the RAM  103  via the DMA controller  105 , the memory controller  104 . 
     Further, the copy image processing circuit  108  changes a method for image processing as to the smoothing process, the edge stressing process, etc. in accordance with the document type (A2, B2, C2) of every page identified by means of the above process for identifying the document types. 
     The printing data producing circuit  109  is a circuit which performs various correction processes on the image data output from the copy image processing circuit  108 , and produces printing data which can be printed by the printing engine  110 . The printing data producing circuit  109  obtains from the RAM  103  the image data of every page on which the various kinds of image processing have been performed by the copy image processing circuit  108 , and performs, e.g., a screening process, a binary encoding process, etc. Then, the printing data producing circuit  109  produces printing data on the basis of the image data on which the various correction processes have been performed and provides the printing engine  110  with the printing data. 
     Further, the printing data producing circuit  109  changes a method for image processing as to the screening process, the binary coding process, etc. in accordance with the document type (A2, B2, C2) of every page identified by means of the above process for identifying the document types. 
     The printing engine  110  carries out printing on the basis of the printing data output from the printing data producing circuit  109 . 
     The image processing device  100  to which the embodiment is applied is configured as described above. The configuration of the image processing device  100 , however, is not limited to the above. The image processing device  100  can be, e.g., a multifunction printer further having a facsimile function or a scanner device lacking the printing engine  110 . 
     Further, each of the portions described above is separately specified in accordance with main processing functions so that how the image processing device  100  is configured can be easily understood. The invention is never limited depending on how the portions are separately specified or what they are called. The configuration of the image processing device  100  can be more finely classified into a greater number of portions in accordance with the processing functions. Further, one of the portions can be specified in such a way as to perform further more processes. Further, a process of each of the portions can be implemented by one hardware unit or by plural hardware units. 
     Further, the block type identifying circuit  107  can be implemented by software by means of a proper program run by the CPU  101 . 
     Then, a distinctive operation of the image processing device  100  that is configured as described above will be explained.  FIG. 3  is a flowchart for explaining a block type identifying process carried out by the block type identifying circuit  107  of the embodiment. 
     The block type identifying circuit  107  starts the flow upon, e.g., being directed to identify the block type by the CPU  101 . 
     After the flow starts, the register I/F  170  of the block type identifying circuit  107  transfers image data (pixel data) of one page from the RAM  103 , via the DMA section  105 , to the smoothing filter  171  on a block-by-block (e.g., 8×8 pixels) basis. Then, as described above, the block type distinguishing circuit  178  is provided with the number of the horizontal edge pixels included in one block via the smoothing filter  171 , the horizontal edge detecting filter  172 , the horizontal edge pixel counter  175 . The block type distinguishing circuit  178  is similarly provided with the number of the vertical edge pixels included in one block via the smoothing filter  171 , the vertical edge detecting filter  173 , the vertical edge pixel counter  176 . Further, the block type distinguishing circuit  178  is provided with the number of the white pixels included in one block via the smoothing filter  171 , the brightness converting circuit  174 , the white pixel counter  177 . 
     The block type distinguishing circuit  178  identifies whether one of the number of the input horizontal edge pixels and the number of the input vertical edge pixels is greater than a certain threshold (e.g., seven pixels). The block type distinguishing circuit  178  identifies as well whether the number of the input white pixels is greater than a certain threshold (e.g., 20 pixels) (step S 101 ). 
     Upon identifying both the number of the input horizontal edge pixels and the number of the input vertical edge pixels as being smaller than the threshold, or identifying the number of the input white pixels as being smaller than the threshold at this step (step S 101 ; No), the block type distinguishing circuit  178  shifts the process to a step S 105 . 
     If the process shifts to the step S 105 , the block type distinguishing circuit  178  identifies the block type of the block as “non-text block” C1, and provides the block type counter  179  with a signal (data) indicating the identified block type (step S 105 ). 
     Meanwhile, upon identifying one of the number of the input horizontal edge pixels and the number of the input vertical edge pixels as being greater than the threshold, and identifying the number of the input white pixels as being greater than the threshold at the step S 101  (step S 101 ; Yes), the block type distinguishing circuit  178  shifts the process to a step S 102 . 
     If the process shifts to the step S 102 , the block type distinguishing circuit  178  identifies whether a ratio R of the number of the input horizontal edge pixels to the number of the input vertical edge pixels is close to one (step S 102 ). The block type distinguishing circuit  178 , e.g., divides the number of the horizontal edge pixels by the number of the vertical edge pixels so as to calculate the ratio R, and identifies whether the calculated ratio R meets a condition “0.8&lt;ratio R&lt;1.2”. 
     Upon identifying the ratio R of the number of the horizontal edge pixels to the number of the vertical edge pixels as being close to one at the step S 102  (step S 102 ; Yes), the block type distinguishing circuit  178  shifts the process to a step S 103 . Meanwhile, upon identifying the ratio R of the number of the horizontal edge pixels to the number of the vertical edge pixels as not being close to one at the step S 102  (step S 102 ; No), the block type distinguishing circuit  178  shifts the process to a step S 104 . 
       FIG. 4A  shows an exemplary ink jet output text document. Further,  FIG. 4B  shows an exemplary laser output text document. As shown there, the ink jet output text is more likely to cause blurring than the laser output text document in general. 
     Thus, if the ratio R of the number of the horizontal edge pixels to the number of the vertical edge pixels is close to one, the block type distinguishing circuit  178  of the embodiment regards the document as causing blurring as edge directions are random, and identifies the input block as an ink jet output block. 
       FIG. 4C  shows an enlarged exemplary ink jet output block. Printed and unprinted pixels are shown by black and white squares, respectively. As the exemplary block shown there has eight horizontal and nine vertical edge pixels, the block type distinguishing circuit  178  regards the block as causing blurring and identifies the block as an ink jet output block. 
     Meanwhile, if the ratio R of the number of the horizontal edge pixels to the number of the vertical edge pixels is not close to one (is biased), the block type distinguishing circuit  178  of the embodiment regards the document as not causing blurring as the edge direction is definite, and identifies the document as a laser output block. 
       FIG. 4D  shows an enlarged exemplary laser output block. Printed and unprinted pixels are shown by black and white squares, respectively. As the exemplary block shown there has eight horizontal and three vertical edge pixels, the block type distinguishing circuit  178  regards the block as not causing blurring and identifies the block as a laser output block. 
     Thus, if the process shifts to the step S 103 , the block type distinguishing circuit  178  identifies the block type of the block as “text and ink jet output block” A1, and provides the block type counter  179  with a signal (data) indicating the identified block type (step S 103 ). Meanwhile, if the process shifts to the step S 104 , the block type distinguishing circuit  178  identifies the block type of the block as “text and non-ink jet output block” B1, and provides the block type counter  179  with a signal (data) indicating the identified block type (step S 104 ). 
     If the process of one of the steps S 103 -S 105  finishes, the block type identifying circuit  107  shifts the process to a step S 106 . 
     If the process shifts to the step S 106 , the block type counter  179  counts the number of blocks of each of the block types (A1, B1, C1) (step S 106 ). To put it specifically, upon receiving a signal indicating the block type A1 from the block type distinguishing circuit  178 , the block type counter  179  incrementally updates a count value for counting the number of the blocks belonging to the block type A1 (note that the initial value is set to 0). Further, upon receiving a signal indicating the block type B1 from the block type distinguishing circuit  178 , the block type counter  179  incrementally updates a count value for counting the number of the blocks belonging to the block type B1 (note that the initial value is set to 0). Further, upon receiving a signal indicating the block type C1 from the block type distinguishing circuit  178 , the block type counter  179  incrementally updates a count value for counting the number of the blocks belonging to the block type C1 (note that the initial value is set to 0). 
     Then, the block type counter  179  keeps the incrementally updated count value (the total number) in memory, and finishes the flow. 
     Incidentally, the above process through the steps S 101 -S 106  is repeated for each of the blocks included in one page. Thus, the block type distinguishing circuit  178  provides the block type counter  179  with one of the block types (A1, B1, C1) for every block (steps S 103 , S 104 , S 105 ). Then, every time the block type counter  179  receives one of the block types (A1, B1, C1) of a block, the block type counter  179  incrementally updates the count value of the block type that the block belongs to. Thus, in the end, the block type counter  179  can obtain the total number of the blocks of each of the block types (A1, B1, C1) for the blocks of one page. 
     Incidentally, each of the processing steps of the flow described above is separately specified in accordance with main processing functions so that the image processing device  100  can be easily understood. The invention is never limited depending on how the processing steps are separately specified or what they are called. The process carried out by the image processing device  100  can be divided into a greater number of processing steps. Further, one of the steps can be specified in such a way as to perform further more processes. 
     Further, after the process of the above flow finishes, the CPU  101  carries out a process for identifying a document type. To put it specifically, the CPU  101  obtains the total number of the blocks of each of the block types (A1, B1, C1) from the block type counter  179  via the register I/F  170 . Then, the CPU  101  specifies the block type of the greatest one of the total numbers of the blocks obtained for the respective block types (A1, B1, C1), and identifies the document type corresponding to the specified block type as the document type of the page. That is, if the total number of the blocks of the block type A1 is greatest in a page, the CPU  101  identifies the document type of the page (scan data) as “text and ink jet output document” A2. Further, if the total number of the blocks of the block type B1 is greatest in a page, the CPU  101  identifies the document type of the page (scan data) as “text and non-ink jet output document” B2. Further, if the total number of the blocks of the block type C1 is greatest in a page, the CPU  101  identifies the document type of the page (scan data) as “non-text document” C2. 
     After the above process for identifying the document type finishes, the copy image processing circuit  108  obtains the image data stored in the RAM  103  (the image data on which various kinds of image processing have been performed by the scanner image processing circuit  106 ) via the DMA section  105 . Then, the copy image processing circuit  108  carries out different kinds of image processing in accordance with the document types (A2, B2, C2) identified by the process for identifying the document types. 
       FIG. 5A  shows an exemplary method for image processing. Further,  FIG. 5B  shows another exemplary method for image processing. 
     As shown in  FIG. 5A , e.g., if the document type identified by the process for identifying the document types is “text and ink jet output document” A2, the copy image processing circuit  108  carries out a smoothing process on the image data obtained from the RAM  103 , and carries out an edge stressing process of a high strength (higher than a certain strength). Even if a document which is likely to cause blurring such as an ink jet output document is scanned, thereby, a clearly visible copied document can be provided. 
     Further, if the document type identified by the process for identifying the document types is “text and non-ink jet output document” B2, the copy image processing circuit  108  does not carry out a smoothing process on the image data obtained from the RAM  103 , and carries out an edge stressing process of a low strength (lower than a certain strength). If a document which is unlikely to cause blurring such as a laser output document, thereby, a copied document can be provided without degrading visibility. 
     Further, if the document type identified by the process for identifying the document types is “non-text document” C2, the copy image processing circuit  108  carries out a smoothing process on the image data obtained from the RAM  103 , and carries out an edge stressing process of a low strength (lower than a certain strength). Even if a document including an image or a figure is scanned, thereby, a copied document can be provided without degrading visibility. 
     Further, as shown in  FIG. 5B , e.g., if the document type identified by the process for identifying the document types is “text and ink jet output document” A2, the copy image processing circuit  108  can carry out a smoothing process on the image data obtained from the RAM  103 , and carry out an edge stressing process of a low strength (lower than a certain strength). 
     Then, the copy image processing circuit  108  stores the image data on which the image processing has been carried out by means of the above image processing methods in the RAM  103  via the DMA section  105 , the memory controller  104 . 
     Here, the CPU  101  image-converts the image data on which the various kinds of image processing have been carried out by the copy image processing circuit  108  in a proper format so as to produce an electronic file. The electronic file produced by the CPU  101  can be, e.g., a PDF (registered trademark) file or a JPEG file. Then, the CPU  101  stores the produced electronic file in the RAM  103 , etc. The CPU  101  corresponds to an output section. 
     Further, in order to print the image data on which the various kinds of image processing have been carried out by the copy image processing circuit  108 , the printing data producing circuit  109  obtains the relevant image data from the RAM  103  via the DMA section  105 . Then, the printing data producing circuit  109  carries out different kinds of image processing in accordance with the document type (A2, B2, C2) identified by the process for identifying the document types. 
     As shown in  FIG. 5A , e.g., if the document type identified by the process for identifying the document types is “text and ink jet output document” A2, the printing data producing circuit  109  carries out a binary encoding process of a high threshold on the image data obtained from the RAM  103 . Even if a document which is likely to cause blurring such as an ink jet output document is scanned, thereby, a clearly visible copied document can be printed. 
     Further, if the document type identified by the process for identifying the document types is “text and non-ink jet output document” B2, the printing data producing circuit  109  carries out a multi-valued screening process on the image data obtained from the RAM  103 . If a document which is unlikely to cause blurring such as a laser output document is scanned, thereby, a copied document can be printed without degrading visibility. 
     Further, if the document type identified by the process for identifying the document types is “non-text document” C2, the printing data producing circuit  109  carries out a multi-valued screening process on the image data obtained from the RAM  103 . Even if a document including an image or a figure is scanned, thereby, a copied document can be printed without degrading visibility. 
     Further, as shown in  FIG. 5B , e.g., if the document type identified by the process for identifying the document types is “text and ink jet output document” A2, the printing data producing circuit  109  can carry out a binary encoding process of a low threshold on the image data obtained from the RAM  103 . 
     Further, if the document type identified by the process for identifying the document types is “text and non-ink jet output document” B2, the printing data producing circuit  109  can carry out a binary encoding process of a high threshold on the image data obtained from the RAM  103 . 
     Then, the printing data producing circuit  109  produces printing data which can be printed by the printing engine  110  from the image data on which the image processing has been carried out by means of the above methods for image processing. The printing data producing circuit  109  transmits the produced printing data to the printing engine  110  so as to print a copied document based on the scan data. 
     The image processing device  100  carries out the process described above so that ink blurring can be made inconspicuous in a case where an ink jet output document is printed. 
     Incidentally, the invention is not limited to the above embodiment, and can be variously modified and applied. 
     The CPU  101  of the embodiment, e.g., carries out the process for identifying the document types described above. The invention, however, is not limited to the above. The process for identifying the document types can be carried out, e.g., by the block type identifying circuit  107 . In this case, the block type identifying circuit  107  is provided with an exclusive circuit for carrying out the process for identifying the document types. 
     Further, as to the embodiment, the block types are identified for all the blocks included in one page. The invention, however, is not limited to the above. The block type identifying circuit  107  can be configured, e.g., to identify the block types for part of the blocks included in one page. The copying process can thereby be speeded up. 
     The entire disclosure of Japanese Patent Application No.2009-198862, filed Aug. 28,2009 is expressly incorporated by reference herein.