Abstract:
An image processing apparatus is provided in which the frequency of undesired delay of the image output can be reduced. The image processing apparatus comprises an image processor for performing a process defined by a parameter on the image data of the received job, a decision portion for deciding a state of the image data of the received job, and a controller for setting a parameter in accordance with the state that is decided by the decision portion if an interval between the received job and the previously received job is longer than a predetermined time, and for setting the parameter that was used in the last job despite the state that is decided by the decision portion if the interval is not longer than the predetermined time.

Description:
This application is based on Japanese Patent Application No. 262905/1999 filed on Sep. 17, 1999, the contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an image processing apparatus for outputting an image by a printer or a display. 
   2. Description of the Prior Art 
   When printing out an image read by a color scanner or a computer graphics, a color compressing process is performed as necessary, in which colors of the image data are converted into colors within a color reproduction range of the printer. 
   Conventionally, a parameter for realizing the optimal color compression (including incompression) is set at every input of a job to an image output device (a request for output one or more pages). 
   In order to decide whether the color compression is necessary or not so as to set the parameter, an appropriate time is required, which causes a delay of the image output. Conventionally, there was a problem that the parameter setting causes the delay of the image output even if a reconfiguration of the parameter is not necessary. For example, there is a waste of time when a user confirms the result of a trial print and then instructs a real print promptly, or when a user finds a shortage of the number of copies and instructs the print of the deficient number of copies, or when instructing a continuous output (job) of plural documents having similar colors. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is to provide an image processing apparatus that can reduce a frequency of the undesired delay of the image output. 
   According to a first aspect of the present invention, an image processing apparatus receives a job including image data and processes the image data of the received job so as to give the job to an output device. The image processing apparatus comprises an image processor for performing a process defined by a parameter on the image data of the received job, a decision portion for deciding a state of the image data of the received job, and a controller for setting a parameter for the received job in accordance with the state that is decided by the decision portion if an interval between the received job and the last job is longer than a predetermined time, and for setting the parameter, that was used in the last job, for the received job despite the state that is decided by the decision portion if the interval is not longer than the predetermined time. 
   According to a second aspect of the present invention, an image processing apparatus receives a job including image data and processes the image data of the received job so as to give the job to any one of plural output devices. The image processing apparatus comprises an image processor for performing a process defined by a parameter on the image data of the received job, an interface for giving the image data processed by the image processor to any one of the plural output devices, a decision portion for deciding a state of the image data of the received job, and a controller for setting a parameter in accordance with the state that is decided by the decision portion. 
   According to a third aspect of the present invention, an image processing method, which is used for performing an image process defined by a parameter on image data, comprises the steps of receiving a job including image data, deciding a state of the image data of the received job, setting a parameter in accordance with the state decided by the deciding step if the interval between the received job and the last job is longer than a predetermined time, while setting the parameter that was used in the last job despite the state that is decided in the deciding step if the interval is not longer than the predetermined time, and performing a image process defined by a parameter on image data of the received job. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram showing the entire structure of an image output system according to the present invention. 
       FIG. 2  is a schematic drawing of the color compression. 
       FIG. 3  is a flowchart showing a general operation of the image processing apparatus. 
       FIG. 4  is a flowchart of the color decision process shown in  FIG. 3 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Hereinafter, the present invention will be explained more in detail with reference to embodiments and drawings. 
     FIG. 1  is a block diagram showing the entire structure of an image output system according to the present invention. 
   The image output system  1  is a network system that includes scanners  11  and  12  and computers  15  and  16  as image input devices, printers  21  and  22  as image output devices, and an image processing apparatus  100 . The image output system  1  is used for copying an original or for printing a document made by using the computers  15  and  16 . The scanners  11  and  12  and the computers  15  and  16  output image data in the RGB color space. The printers  21  and  22  perform color printing by a subtractive process of CMYK. Since the image processing apparatus  100  is connected to four image input devices and two image input devices, the image output system  1  has eight (4×2) combinations of input and output devices. If the scanners  11 ,  12  and the printers  21 ,  22  have fixed correspondence, there are six combinations. In any case, one of the combinations is selected by the image processing apparatus  100  for each job. 
   The image processing apparatus  100  has an interface  101  for selecting an input and an interface  102  for switching the output target. The interface  101  selects one image input device that requested a job and does not receive any job request from the other image input device until the job is completed. The interface  102  selects one of the printers  21  and  22  as the output target in accordance with the job that the interface  101  received. These interfaces  101  and  102  send connection identifications C 1  and C 2  that indicate the selected state to the CPU  107 . 
   As an example of the job, copying of plural originals by the scanner  11  and the printer  21  will be adopted in the following explanation of the image processing apparatus  100 . The scanner  11  reads images of plural originals set on a table (not shown) sequentially and sends the image data to the image processing apparatus  100 . The interface  101  sends input data from the scanner  11  as the image data D 1  to be processed to an image memory  104 . The image memory  104  memorizes all image data D 1  concerning the present job temporarily. In parallel with this memorizing, the image data D 1  of each page are sent from the image memory  104  to a color space decision portion  105  sequentially. The color space decision portion  105  is supplied from a printer color space memory portion  106  with data that indicate a color reproduction range r 0  of the printer  21  selected by the interface  102 . The color space decision portion  105  decides whether a color range of the image data D 1  of each page is partially out of the color reproduction range r 0  or not. The detail of the decision will be explained later. In accordance with the decision result Dj, the CPU  107  sets a parameter Dp that defines process contents of an image processing portion  103 . The image processing portion  103  can perform an image improving process such as a color conversion from RGB to CMYK or, a γ correction or an edge emphasis, and a color compression on the image data D 1  read out of the image memory  104 . Since the CPU  107  set the parameter by a job unit, the color compression is not performed for the image data D 1  of all pages of one job. Otherwise, the color compression is performed uniformly for the image data D 1  of all pages of one job. The output (i.e., the image data) of the image processing portion  103  is sent to the printer  21  via the interface  102 . The time point when the image data D 2  of all pages are sent out completely is the end of the job in the image processing apparatus  100 . 
   The image processing apparatus  100  decides whether the color compression is necessary or not for every job input except the “specific case” and sets a parameter Dp in accordance with the decision result Dj so as to perform the image processing. The “specific case” includes, e.g., the case where a new job is inputted during a predetermined period of maintaining the state from the end of a job and the combination of input and output devices concerning the latest job is the same as the last job. In this case, the color space decision portion  105  does not work substantially, and the CPU  107  sets a parameter Dp that was adapted by the last job to the image processing portion  103 . Namely, it is regarded that the state of the color display has not changed, so the parameter Dp is not changed. For the image data D 1  of the latest job, the image processing portion  103  performs the process having the same contents as the last job. Since the decision of the necessity of the color compression and the determination of the optimum parameter Dp can be omitted, the image process can be started early, so that the time required for the job can be shortened. 
   The set parameter Dp is memorized by the non-volatile memory  109  of the CPU  107  along with management data DM for distinguishing the job such as the date and time, the input image number and the input device name. 
   During the period of waiting for the input of job, the CPU  107  instructs a list display of the stored management data DM to a display portion  108 . The display portion  108  is a user interface having an input key. The display portion  108  displays the management data DM and reports the operation input contents SS to the CPU  107 . When the user selects the management data DM (i.e., the job in the past), the CPU  107  read the parameter Dp corresponding to the selected management data DM out of the memory  109  so as to give the data to the image processing portion  103 . In this case too, the decision of the necessity of the color compression for the image data D 1  is omitted. 
   If a structure is adapted in which a predetermined specific parameter (e.g., a parameter having the largest setting frequency in the past) is automatically selected and set when the state maintaining time passes from the end of a job, the opportunity that the user does not need to perform the selection increases depending on the using state. The state maintaining period can be adjusted by the user and be set for each kind of the job (a copy or a print) independently. 
     FIG. 2  is a schematic drawing of the color compression. 
   The above-mentioned color space decision portion  105  converts the RGB image data D 1  into data in a standard color space (e.g., a CIELAB color space) and decides whether the color of pixel of each page is a color within the color reproduction range r 0  of the printer regarding each of blocks q 1 –q 6  that are generated by dividing the standard color space Q by a predetermined number (six in this example) in accordance with the tint. The color space decision portion  105  sends data as a decision result Dj to the CPU  107 . The data indicate the ratio of the number of pixels which are out of the printer color reproduction range to the number of pixels in each block q 1 –q 6  (the area ratio). The CPU  107  memorizes the decision result Dj that is given for each page, decides the necessity of the color compression for each block in accordance with the decision result Dj of one job, and calculates a parameter Dp, which is given to the image processing portion  103 . In the example shown in  FIG. 2 , the color range r 1  of the first page is partially out of the color reproduction range r 0  in the block q 1 . The color range r 2  of the second page is partially out of the color reproduction range r 0  in the blocks q 3  and q 4 . In this case, as shown by arrows in  FIG. 2 , the image processing portion  103  performs the color compression of converting the color of the image data D 1  of the portion of the first page that corresponds to block q 1  into a color within the color reproduction range r 0  and performs the similar color compression for the blocks q 3  and q 4 . In the same way, the image processing portion  103  performs the color compression of the image data D 1  of the second page about the blocks q 3  and q 4 , as well as about the block q 1 . 
     FIG. 3  is a flowchart showing a general operation of the image processing apparatus. 
   When a job is inputted in the waiting state, the connection identifications C 1  and C 2  are analyzed for determining a combination of the input and the output devices and the color reproduction range r 0  (# 1 ). The color decision process is performed for examining the relationship between the color range of the image data D 1  and the color reproduction range r 0  of the printer (# 2 ). A parameter Dp that is suitable for the job is set in accordance with the information obtained in the color decision process (# 3 ), and the image data D 1  is converted into image data D 2  that is suitable for the reproduction thereof so as to output the data (# 4 ). A job management timer is set for measuring the state maintaining period Tw (# 5 ). If the next job is inputted before the end of the timer, the connection identifications C 1  and C 2  are analyzed so as to check whether the combination of the input and the output devices is different from the last job (# 6 –# 9 ). If the assignments are the same, the image output process is performed promptly (# 9 , # 4 ). If the assignments are different, the color decision process is performed, and the parameter Dp is reset so as to perform the image output process (# 9 , # 2 ). 
     FIG. 4  is a flowchart of the color decision process shown in  FIG. 3 . 
   First, the kind of the job is checked (# 21 ). If it is a copy job, image data D 1  of one page are fetched in synchronization with the reading of originals by scanners  11  and  12 , and the above-mentioned area ratio is calculated for each block of the color space Q (# 22 –# 24 ). When the calculation of the area ratio is finished for all pages by repeating the data fetch (# 25 ), the cumulative value of the area ratio is analyzed for all pages, and the necessity of the color compression is decided for each block (# 28 ). In the case of the print job, in the same way as in the copy job, the area ratio is calculated for each page in the image data D 1  that are inputted as a unit for one job, the area ratios of all pages are accumulated, and the cumulative value is analyzed so as to decide whether the color compression is necessary or not for each block (# 26 –# 28 ). 
   According to the above-mentioned embodiment, if at least one page of image data is data that are partially out of the printer color reproduction range, the color compression is performed uniformly on the image data D 1  of all pages of the job. Therefore, in contrast to the case where the color compression is performed or not performed for each page, the tint of the reproduction color is not different among pages. If a user selects the job in the past by observing the displayed management data DM, the parameter can be set indirectly. Therefore, the user can obtain a printed result having the same color reproducibility as the printed result in the past. 
   In the above-mentioned embodiment, the system has a configuration in which the scanner and the printer are separated. However, the present invention can be applied to a copying machine that has a single unit of scanner and printer. In this case, the image processing apparatus  100  is built in the copying machine, and an operation panel of the copying machine may work as the display portion  108 . 
   The kinds and the numbers of the image input devices and the image output devices are not limited to the example of the above-mentioned embodiment. If there are plural image output devices, it is possible that the user selects one output device using the display portion  108 . The dividing number of the color space Q is not limited to six. It is possible to decide whether the color compression is necessary or not without dividing the color space Q. 
   According to the present invention, the frequency of undesired delay of the image output can be reduced. 
   While the presently preferred embodiments of the present invention have been shown and described, it will be understood that the present invention is not limited thereto, and that various changes and modifications may be made by those skilled in the art without departing from the scope of the invention as set forth in the appended claims.