Patent Publication Number: US-2005135676-A1

Title: Document processor

Description:
FIELD OF THE INVENTION  
      The present invention relates to a document processor that reads document sheets and the like as color image data, and process the image data in different ways.  
     BACKGROUND ARTS  
      Document processors have been suggested for example in Japanese Laid-open Patent Applications Nos. 2002-197413 and 2003-76939, which read many kinds of document sheets, e.g. delivery slips and applications for insurance, by use of an imaging device, such as a CCD line sensor, and carry out image dropout processing whereby unnecessary objects, like ruled lines, are converted into white or the same color as a base color of the sheet, to output a binary black-and-white image.  
      Because the document processors disclosed in the above mentioned prior arts can designate only one color to be dropped out of the image, they do not work for such cases where the document sheets contain many colors. In order to deal with different kinds of document sheets in the prior arts, setup values for image-processing must be changed for each individual kind of document sheets. Moreover, because the prior arts can only produce image data of one kind, i.e. a binary image, from the read document sheet, it is difficult to classify and keep the data on file. Therefore, the prior arts are not practical in term of data management.  
     SUMMARY OF THE INVENTION  
      In view of the foregoing, a primary object of the present invention is to provide a document processor that can carry out a wide variety of image processing at high speed.  
      According to the present invention, a document processor comprises an image reader for reading a document sheet to output image signals; and an image processing section previously registered with a number of colors to be subjected to image processing, wherein different contents of image processing are designated to the respective colors, so that the image processing section detect pixels of those colors to be subjected to the image processing, and carries out the different contents of image processing simultaneously on the detected pixels.  
      According to a preferred embodiment of the invention, the image signals are RGB signals, and the document processor further comprises a color model converter for converting the RGB signals to HSV signals and YUV signals through arithmetic operations, and attaching the YUV signals to the HSV signals of individual pixels, wherein the image processing section refers to the YUV signals to detect those pixels to be subjected to the image processing.  
      It is preferable to provide the document processor of the invention with a document distinguisher for determining the kind of the document sheet on the basis of the image signals, and outputting a determination result to the image processing section, so the image processing section automatically decides the contents of image processing in accordance with the determined kind of document sheet.  
      The document processor preferably comprises a data output section that outputs unprocessed original image data of the document sheet on the basis of the YUV signals as attached to the HSV signals.  
      According to a further preferred embodiment, the image processing section carries out at least one of dropout processing, color enhancement, color extraction and area recognition on the image signals, wherein the dropout processing is to convert the registered colors to white or a base color of the document sheet, the color enhancement is to convert the registered colors to black or deeper colors, the color extraction is to drop out other colors than the registered colors, and the area recognition is to recognize those areas which are shown in the registered colors, and cut out or mask out the recognized areas.  
      In the area recognition, the image processing section preferably converts those HSV signals which represent colors of the recognized areas to HSV{0, 0, 0} that represent black.  
      It is also preferable to provide the document processor with a device for designating some sections of the document sheet to be included in or excluded from the subject of image processing in the image processing section.  
      Because a number of colors to be subjected to image processing, and different contents of image processing are designated to the respective colors, the image processing section of the document processor of the present invention can detect pixels of those colors to be subjected to the image processing, and carries out the different contents of image processing simultaneously on the detected pixels. Accordingly, the document processor of the present invention can carry out a wide variety of image processing at high speed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other advantages of the present invention will become more apparent from the following description of the preferred embodiments when read in connection with the accompanying drawings, wherein like reference numerals designate corresponding parts throughout several views:  
       FIG. 1  is a schematic diagram illustrating a document processor according to an embodiment of the present invention;  
       FIG. 2  is a schematic view of an example of document sheet;  
       FIG. 3  is a block diagram illustrating an electric structure of the document processor;  
       FIG. 4  is an explanatory diagram illustrating a data structure produced in the document processor, wherein YUV signals are attached to HSV signals; and  
       FIGS. 5A and 5B  show a flow chart illustrating a sequence of operation of the document processor. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      A document processor  2  shown in  FIG. 1  is constituted of a feeder  11  that automatically feeds document sheets  10  one by one into the document processor  2 , a bar code reader  12  for reading bar codes  33 , see  FIG. 2 , from the document sheet  10 , an imprinter  13  for printing a serial number or the like on the document sheet  10 , an image reader  14  for reading the document sheet  10 , a turning section  15  for turning over the document sheet  10 , a stacker  17  for ejecting and stacking up the document sheet  10  after being read, and a secondary stacker  16  for ejecting unreadable slips  10  or for ejecting and stacking up the document sheet  10  while sorting them. The document processor  2  conveys the document sheet  10  through a conveying path  18  as shown by phantom lines in  FIG. 1 , by use of not-shown conveyer rollers. The document sheet  10  is conveyed with its obverse side up, as the image reader  14  reads the document sheet  10 . Image data read out through the image reader  14  is processed in a manner as set forth later.  
      The image reader  14  consists of a color CCD line sensor  19  and a light source  20  for illuminating the obverse side of the document sheet  10  with white light. The image reader  14  allows designating the size of the document sheet  10  to read out, and carries out a compensation process for a slant of the document sheet  10 , and a contrast-conversion process. It is possible to dispose a second image reader across the conveying path  18  from the image reader  14 , for reading a back side of the document sheet  10  at the same time when the obverse side of the document sheet  10  is read by the image reader  14 . The second image reader may have the same structure as the image reader  14 . The color CCD line sensor  19  has 7500 pixels in this embodiment, so it can read the document sheets  10  at a resolution of 600 dpi, 400 dpi, 300 dpi, or 200 dpi, to output analogpicture signals. The picture signals are amplified by a not-shown amplifier, and then converted through a not shown A/D converter into digital RGB signals.  
      The document sheet  10  has a base  30  that is shown as a dotted area in  FIG. 2 , on which blank frames  31  for filling in the information, like user&#39;s name, telephone number and address, and ruled lines  32  for partitioning these blank frames  31  into individual groups are formed.  
      Also a bar code  33  is formed on the base  30 , to represent information on the shop or the like that issues the document sheet  10 . The present embodiment assumes that the document processor  2  can deal with eight kinds of document sheets, and distinguishes between different kinds of document sheets by the color of the base  30  or the color of the ruled lines  32 .  
      The document processor  2  has an internal structure as shown in  FIG. 3 , wherein a CPU  40  is connected through a bus  41  to respective parts, so as to control the overall operation of the document processor  2 . Concretely, the bus  41  is connected to the image reader  14 , a color model converter  42 , a color detector  43 , a document distinguisher  44 , a color converter  45 , a color extractor  46 , an area recognizer  47 , a ROM  48 , a RAM  49 , a data output section  50 , a data compressor  51  and a communication interface  52 .  
      The CPU  40  is also connected to a console  53 . The console  53  consists of data input devices, such as a keyboard and amouse. The console  53  is used for registering base colors of the document sheets to deal with, for registering colors to be subjected to image processing, for designating a content of image processing to each of the registered colors, for designating some sections of the document sheet  10  to be included in the subject of image processing, or excluded from the subject of image processing, as well as for designating an output format of processed image data. The CPU  40  controls the respective parts in response to command data input through the console  53 .  
      It is to be noted that the color converter  45 , the color extractor  46 , and the area recognizer  47  constitute an image processing section  55 . The colors registered through the console  53  are entered in a format according to HSV (hue, saturation, value) system. It is also possible to connect a host computer to the document processor  2  through the communication interface  52 , so that the above data may be entered through a keyboard or a mouse of the host computer.  
      The color model converter  42  converts the RGB signals from the image reader  14  into HSV signals and YUV signals through operations. Then the color model converter  42  attaches the YUV signals to the respective HSV signals of the individual pixels of the CCD line sensor  19 . The HSV signals and the YUV signals are obtained from the RGB signals through the following operations: 
 
 V =max( R,G,B ); 
 
Δ=max( R,G,B )−min( R,G,B ); and 
 
 S =Δ/max( R,G,B ), 
          wherein max(R,G,B) and min(R,G,B) respectively represent a maximum value and a minimum value among the RGB signals, and wherein S=0 and H=−1 (undefined) when max(R,G,B)=0, and H=60{(G-B)/Δ} when max(R,G,B)=R, and H=60{2+(B-R)/Δ} when max(R,G,B)=G, and H=60{4+(R-G)/Δ} when max(R,G,B)=B. If H&lt;0, 360 is added. 
 
 Y= 0.299 R+ 0.587 G+ 0.114 B;  
 
 U=− 0.169 R− 0.331 G+ 0.500; and 
 
 V= 0.500 R− 0.419 G− 0.081 B.  
       

       FIG. 4  shows the structure of the data obtained by the color model conversion, wherein 8 bits are assigned to each value (Y, U, V) of the YUV signal, 10 bits to the H-value of the HSV signal, and 7 bits to each of the S- and V-values of the HSV signal. In total, each data unit consists of 5 bytes. The values (U, V) of the YUV signal are separately allocated to two adjacent pixels. To avoid confusion, “Va” represents the V-value of the HSV signal, whereas “Vb” represents the V-value of the YUV signal.  
      The color detector  43  detects pixels of those colors which are to be processed, and sends the detection results to the document distinguisher  44 , the color converter  45  and the color extractor  46  and the area recognizer  47 . The respective sections  44  to  47  carry out different types of image processing on the basis of the color detection results from the color detector  43 , as set forth below. It is alternatively possible to provide the respective sections  44  to  47  with individual color detectors.  
      The document distinguisher  44  determines the kind of the document sheet  10  with reference to the YUV signals produced from the color model converter  42 , and notifies the determination result to the CPU  40 . The document distinguisher  44  has a number of counters. Each counter counts the number of those pixels which are included in a color range of one of previously registered base colors. As set forth above, the base colors of the different kinds of document sheets are previously registered through the console  53 . Accordingly, the counters represent the respective base colors. Among of these counters, the one counting up to the highest value represents the base color of the exiting document sheet  10 , so that the kind of the existing document sheet  10  is determined by the base color. The counter may count the number of pixels in the whole area of the document sheet  10 , or within a section of the document sheet  10 , which is also designated through the console  53 .  
      The color converter  45  performs a dropout process to convert designated colors into white or the same color of the base  30 , or a color enhancement process to convert designated colors into black or make them deeper. The dropout process and the color enhancement process are performed in a section designated through the console  53 . The color extractor  46  performs a process to drop other colors than a designated color out of a section that is designated through the console  53 . The area recognizer  47  recognizes an area which is shown in a registered color within a section designated through the console  53 , and cuts out or masks these areas. In the present description, the area determined by the area recognizer  47  includes a fragment bordered with the registered color or a fragment colored in the registered color.  
      The color converter  45 , the color extractor  46  and the area recognizer  47  do not apply the image processing to those sections of the document sheet  10  which are designated to be excluded from the subject of the image processing. The designation is made through the console  53 . The section to be excluded from the subject of the image processing may for example be a section having the title of the document sheet  10 .  
      The color converter  45  and the color extractor  46  carry out the designated image processing while checking each individual pixel as to if it is the subject of the image processing, with reference to the YUV signal that is attached to the HSV signal of each pixel in the color model converter  42 . For example, when green lines  32  are to be converted to blue, and blue lines  32  are to be dropped out into white, the conversion to blue is applied to the HSV signals of those pixels which are included in the color range of the green lines  32 . Then, those pixels being included in the color range of the blue lines  32  are detected with reference to the YUV signal, so that the HSV signals of these pixels are dropped out into white. This method prevents double conversion that the blue portions obtained by the blue-conversion of the green lines  32  are unexpectedly dropped out into white through the following dropout process of the blue lines  32 .  
      The area recognizer  47  converts those HSV signals which represent the color of the recognized area, to black, i.e. HSV (0, 0, 0). Thereafter, the area recognizer  47  judges continuity of pixels of the determined area, to carry out a tracing process to detect the area size: vertical and horizontal lengths of the area, and width of enclosing lines. The area size detected through the tracing process is fine-adjusted in the unit of one pixel, and thereafter, the area is cut out or subjected to a masking process whereby the area is blacked out or painted out.  
      To cut out a particular area that contains user&#39;s name, address and telephone number, the particular area is previously enclosed with a color marker or the like, and the color of the marker is previously registered as the subject of the image processing. To mask out such an area that contains private information like a password and user&#39;s annual income, the area is previously painted out with a previously registered fluorescent color. Alternatively, it is possible to register the color of lines that enclose those areas which will contain private information.  
      The CPU  40  controls the operation of the color converter  45 , the color extractor  46  and the area recognizer  47  in accordance with the kind of the document sheet  10  that is determined by the document distinguisher  44 , so as automatically to carry out the image processing designated for each kind of the document sheet  10  through the console  53 .  
      The ROM  48  stores programs and data necessary for the operation of the document processor  2 . The RAM  49  stores the result of distinction by the document distinguisher  44 , the colors and contents of image processing that are registered for the individual kinds of document sheets, the base colors that are used for distinguishing between the different kinds of document sheets, data of color images, gray-scale images and binary images that are output from the data output section  50 , and compressed data of these images.  
      The data output section  50  outputs processed image data after converting them into a designated output format, that is, as a color image, as a gray-scale image or as binary image data, wherein the data output section  50  can output data of different formats simultaneously. The output format is designated through the console  53  in accordance with the content of the image processing. Simultaneously with the processed image data, the data output section  50  also outputs the original image data, i.e. the image data before being processed, on the basis of the YUV signals attached to the HSV signals, after converting them into a designated output format. For example, the data output section  50  output binary image data of a cutout area, which is cutout by the area recognizer  47 , simultaneously with original color image data of the whole document sheet  10 . Thus, the data output section  50  can simultaneously output data of different formats. In a case where a number of areas are cut out by the area recognizer  47 , data of each cutout area are output separately from each other.  
      In the present embodiment, the data compressor  51  compresses the data of color images and gray-scale images into JPEG format data. On the other hand, the binary image data are compressed according to TIFF-G4 format. The data compressed in the data compressor  51  is stored in the RAM  49 . The data stored in the RAM  49  may be sent to external apparatuses through the communication interface  52  and an USB connector  54 .  
      Now the operation of the document processor  2  will be described with reference to the flowchart shown in  FIGS. 5A and 5B .  
      First the operator operates the console  53  to designate and register necessary items, and enters a start command. Then the document sheets  10  are sequentially fed from the feeder  11  into the document processor  2 . The bar code reader  12  reads the bar code  33  on the document sheet  10 , and the imprinter  13  prints a serial number or the like on the document sheet  10 . Thereafter the CCD line sensor  19  of the image reader  14  reads the document sheet  10 . The picture signals from the CCD line sensor  19  are amplified by the not-shown amplifier, and then converted through the not shown A/D converter into digital RGB signals.  
      The RGB signals from the image reader  14  is converted through the color model converter  42  into HSV signals and YUV signals. Then YUV signals are attached to the respective HSV signals of the individual pixels of the CCD line sensor  19 .  
      After the color model conversion, the color detector  43  detects pixels of those colors which are to be processed, and sends the detection results to the document distinguisher  44 , the color converter  45  and the color extractor  46  and the area recognizer  47 . In the respective sections  44  to  47 , different types of image processing are carried out on the basis of the color detection results from the color detector  43 .  
      In the document distinguisher  44 , the kind of the document sheet  10  is determined with reference to the YUV signals produced from the color model converter  42 , and the determination result is notified to the CPU  40 . In accordance with the kind of the document sheet  10  that is determined by the document distinguisher  44 , the CPU  40  controls the operation of the color converter  45 , the color extractor  46  and the area recognizer  47  so as automatically to carry out the image processing designated for each kind of the document sheet  10 .  
      If the content of image processing is color conversion, the color converter  45  is activated to perform the dropout process to convert registered colors into white or the same color of the base  30 , or the color enhancement process to convert other registered colors into black or make them deeper, within a section designated through the console  53 . If the content of image processing is color extraction, the color extractor  46  is activated to drop other colors out of a designated section than a registered color.  
      At that time, the color converter  45  and the color extractor  46  simultaneously carry out the designated contents of image processing while checking each individual pixel as to if it is the subject of the image processing, with reference to the YUV signal that is attached to the HSV signal of each pixel in the color model converter  42 .  
      If the content of image processing is area tracing, the area recognizer  47  is activated to recognize the area that is shown in the registered color in the designated section, and convert those HSV signals which represent the color of the recognized area to HSV (0, 0, 0) that represent black.  
      After the data conversion, the continuity of pixels is detected in this area, to make the tracing process for determining the area size, including the vertical and horizontal length of the area and the line width of the enclosing line. After the area size detected through the tracing process is fine-adjusted in the unit of one pixel, the area is cut out or subjected to the masking process to black out or paint out the area.  
      As shown in  FIG. 5B , the processed image data are converted through the data output section  50  into such output formats that are designated in accordance with the content of the image processing through the console  53 , namely, into color image data, gray-scale image data or binary image data, and are simultaneously output from the data output section  50 . Also the original image data, i.e. the image data before being processed, are converted into a designated output format on the basis of the YUV signals attached to the HSV signals, and are output simultaneously with the processed image data. After being output from the data output section  50 , the color image data and the gray-scale image data are compressed through the data compressor  51  according to the JPEG format. The binary image data are compressed according to TIFF-G4 format. The compressed data are stored in the RAM  49 .  
      The document sheet  10  read by the CCD image sensor  19  is inverted through the turning section  15  to orient the back side up when it is stacked on the stacker  17 . If the kind of the document sheet  10  is not determined by the document distinguisher  44  or the document sheet  10  is judged to be unreadable, the document sheet  10  is ejected to the secondary stacker  16 . In this way, the document sheet  10  is ejected to and stacked on either the stacker  17  or the secondary stacker  16  depending upon the judgment by the document distinguisher  44 .  
      As described so far, the color conversion and the color extraction are carried out while checking each individual pixel with reference to the YUV signals as to if the pixel is the subject of image processing. Therefore, the lodger processor of the present invention can make batch processing, whereby a plural number of colors are simultaneously processed in different ways without the danger of unexpected double conversion. Accordingly, it is unnecessary to change the set up values when the lodger sheets  10  to deal with contain a number of colors, or when different kinds of lodger sheets are to be processed. Because those HSV signals which represent the color of the recognized area, are converted into HSV {0, 0, 0} that represent black, high-speed area recognition processing is achieved. Furthermore, because the lodger processor of the present invention can output data in different formats, it is easy to manage the output data.  
      It is possible to apply the above described color conversion or color extraction not only to a section designated through the console  53  but also to an area that is cut out by the area recognizer  47 . In the above embodiment, one of the color conversion, color extraction and area recognition is carried out on one lodger sheet  10 . But it is possible to carry out more than one of these processes on one lodger sheet  10 .  
      Although the present invention has been described with respect to the preferred embodiments, the present invention is not to be limited by the embodiments but, on the contrary, various modifications will be possible without departing from the scope and spirit of the present invention as specified in appended claims.