JP2012227598A - Image processor, image forming apparatus, image processing method, image processing program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily and properly image-process image data in a line width exceeding a line buffer width.SOLUTION: In a copying apparatus 1, when the line width of the image data on a processing object image, which is read by a reading unit 2 and is stored in a RAM 3, is larger than the line width of a line buffer Lb, an image processing device 4 divides the image data into horizontal regions Ah at every number of prescribed lines in a horizontal direction, divides the horizontal region Ah into a plurality of vertical regions Av in the prescribed line width which is equal to or lower than the line width of the line buffer Lb in a vertical direction, sequentially transfers the image data from the image data of the vertical region Av on a top side in a prescribed line direction to the line buffer Lb among the vertical regions Av belonging to the horizontal region Ah at every horizontal region Ah, performs a prescribed image processing on the image data of the line buffer Lb and couples the image data which is image-processed at every vertical region Av by adjusting it to the image data of the processing object image.

Description

  The present invention relates to an image processing apparatus, an image forming apparatus, an image processing method, an image processing program, and a recording medium, and more specifically, image processing for efficiently and quickly image processing image data having a line width exceeding the line buffer width. The present invention relates to an apparatus, an image forming apparatus, an image processing method, an image processing program, and a recording medium.

  When image data input for each line from a scanner or an external device is subjected to line processing by an image processing device such as an ASIC (Application Specific Integrated Circuit), the size of the image in the horizontal direction is conventionally limited to that of a line buffer. If it is within the line width, as shown in FIG. 13, the input image data is sequentially stored in a RAM (Random Access Memory) 100, and the image data on the RAM 100 is sequentially stored in a line buffer having a predetermined line width. Image data in the buffer is read and image processing is performed for each line by the image processing device. In this case, since the input image is not divided, for example, when the scanner reads an image of one line and outputs the image data to the RAM 100, the line image data in the RAM 100 is immediately read into the line buffer by the image processing device and processed. The image processing can be executed in real time according to the reading speed of the scanner.

  However, image processing cannot be performed on input image data having a line width exceeding the line width of the line buffer.

  Therefore, conventionally, in order to appropriately perform image processing even for image data having a line width exceeding the line width of the line buffer, when the horizontal pixel width of the input image is larger than the line width of the line buffer, The image is divided equally in the vertical direction, and the line width of the divided area is made smaller than the horizontal pixel width (line width) of the line buffer, and the image data is sequentially transferred to the line buffer for each equally divided area. Thus, a technique for image processing has been proposed (see Patent Document 1).

  That is, in the prior art described in this publication, when the horizontal pixel width of the input image data is larger than the line width of the line buffer, for example, the line width of the image is 2 of the line width as shown in FIG. If it is doubled, the image is equally divided into the area 1-1 and the area 1-2 in the vertical direction, and the image data read by the scanner is stored in the RAM 101 in the area 1-1 and the area 1-2, respectively. The image data of the area 1-1 is read out from the line buffer to the line buffer to perform image processing, and then the image data of the area 1-2 is read out to the line buffer to perform image processing.

  However, the prior art described in the above publication has a problem that the processing speed is lowered and the productivity is poor. That is, in the prior art described in the publication, the processing of the area 1-2 is started after the processing of the area 1-1 is completed. If the scanner does not complete the reading of the entire area of the image, the area 1 Since the image processing of -1 does not end, the image processing of the region 1-2 is started after the scanner completes reading of the entire region of the image. Accordingly, there is a problem that it takes time to start the image processing of the area 1-1, the entire processing time is delayed, and the productivity is lowered.

  Accordingly, the present invention provides an image processing apparatus, an image forming apparatus, an image processing method, and an image processing program capable of rapidly processing image data having an image width exceeding the line width of the line buffer without increasing the circuit scale. And it aims at providing a recording medium.

  In order to achieve the above object, according to the present invention, when the line width of the image data of the processing target image is larger than the line width of the line buffer having a predetermined line width, the image data is horizontally converted every predetermined number of lines in the horizontal direction. And dividing the horizontal region into a plurality of vertical regions with a predetermined line width equal to or smaller than the line width of the line buffer in the vertical direction, and among the vertical regions belonging to the horizontal region for each horizontal region, The image data of the vertical area at the beginning of the predetermined line direction is sequentially transferred to the line buffer, and the image data transferred to the line buffer is subjected to predetermined image processing, and the image processing is performed for each vertical area. The image data is combined in accordance with the image data of the processing target image.

  In the present invention, the image processing to be processed with reference to the image data of other lines stored in the line buffer in which the image data for a plurality of lines is stored is interrupted to execute other image processing. In addition, data necessary for interrupting and resuming the image processing being executed may be stored in the intermediate data storage unit as intermediate data.

  Furthermore, the present invention may be characterized in that the intermediate data stored in the intermediate data storage unit is appropriately selected.

  According to the present invention, image data having an image width exceeding the line width of the line buffer can be promptly processed without increasing the circuit scale.

1 is a block diagram of a main part of a copying apparatus to which an embodiment of the present invention is applied. Explanatory drawing of write-in operation to RAM by a reading unit. Explanatory drawing of the read operation from RAM by an image processing device. Explanatory drawing of the data read from RAM by an image processing device, and image processing. Explanatory drawing of the 5th line reference two-dimensional filter process of the N-1st line. Explanatory drawing of the image process using intermediate data. Explanatory drawing of the image processing following FIG. 6 using intermediate data. Explanatory drawing of the image processing of the continuation of FIG. 7 using intermediate data. The figure which shows an example of the line buffer in the case of performing another process in the middle of a filter process. Explanatory drawing of the 5th line reference two-dimensional filter process of the Nth line. The figure which shows an example of the intermediate data for high image quality. The figure which shows an example of the intermediate data for high-speed processing. Explanatory drawing of an image process in case the image horizontal direction pixel number is less than the line buffer width. Explanatory drawing of the image process which divides | segments an image only in the conventional perpendicular direction.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 12 are diagrams illustrating an embodiment of an image processing apparatus, an image forming apparatus, an image processing method, an image processing program, and a recording medium according to the present invention. FIG. 1 illustrates an image processing apparatus and an image according to the present invention. 1 is a block configuration diagram of a copying apparatus 1 to which an embodiment of a forming apparatus, an image processing method, an image processing program, and a recording medium are applied.

  In FIG. 1, a copying apparatus (image forming apparatus) 1 includes a reading unit 2, a RAM 3, an image processing unit 4 as an image processing apparatus, etc., and a controller, a hard disk, a printer unit, a network connection unit, An operation display unit and the like are provided.

  The reading unit 2 includes a light source, an optical system, a photoelectric conversion element, and the like. The reading unit 2 performs main scanning and sub-scanning on a document image, and writes image data corresponding to the document image to the RAM 3 line by line.

  A RAM (intermediate data storage means) 3 has a predetermined line width and a predetermined capacity. The RAM 3 has a capacity for storing image data for one original size that can be read by the reading unit 2, and the reading unit 2 stores the read original image data for each line as shown in FIG. Are sequentially written in the RAM 3.

  Although not shown, the image processing device (image processing means, data management means, image data combining means) 4 has a line buffer Lb corresponding to a predetermined number of lines whose line width is shorter than the maximum reading width of the reading unit 2 (see FIG. 5). The image data of the RAM 3 is taken into the line buffer Lb and subjected to predetermined image processing such as filter processing, black-and-white inversion processing, γ correction processing, gradation processing, etc. Are combined in the arrangement order of the image data before processing and output to a controller (not shown).

  The controller includes a central processing unit (CPU), a read only memory (ROM), a RAM, and the like, and controls each part of the copying apparatus 1 as a copying apparatus 1 while using the RAM as a work memory based on a program in the ROM. And the image processing device 4 is controlled to execute an image processing method for quickly and appropriately image processing the image data exceeding the line width of the line buffer Lb of this embodiment. The controller temporarily stores the image data sent from the image processing device 4 in the hard disk, then converts the image data into a data format that can be printed by the printer unit, and transfers the data to the printer unit. The printer unit is sent from the controller. An image is formed on a sheet based on the received image data. The controller also transfers the image data stored on the hard disk to an external device such as a computer connected to the network.

  The operation display unit includes an operation key for inputting various commands to the copying apparatus 1 and a display unit for displaying the contents of the input commands and various types of information notified to the user from the multifunction device 1.

  That is, the copying apparatus 1 includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a CD-RW (Compact Disc Rewritable), a DVD ( An image processing program for executing the image processing method of the present invention recorded on a computer-readable recording medium such as a digital versatile disk (SD), a secure digital (SD) card, or a magneto-optical disc (MO) is read into a ROM or It is an image forming apparatus equipped with an image processing apparatus that executes an image processing method for quickly and appropriately performing image processing on image data exceeding the line width of a line buffer Lb of an image processing device 4 to be described later by being installed in a hard disk. It is constructed as a copying apparatus 1. This image processing program is a computer-executable program written in a legacy programming language such as assembler, C, C ++, C #, Java (registered trademark) or an object-oriented programming language, and is stored in the recording medium. Can be distributed.

  The network connection unit is connected to a network such as a local area network (LAN), and exchanges data and commands with an external device connected to the network via the network. That is, when image data and a command are sent from an external device via a network, the copying apparatus 1 performs necessary image processing by the image processing device 4 on the image data sent based on the command. After that, it prints out with the printer unit. Further, when data transfer is requested by a command from an external apparatus, the copying apparatus 1 performs image processing of the image data of the document read by the reading unit 2 by the image processing device 4 and then via the network. Transfer to the external device.

  Next, the operation of this embodiment will be described. The copying apparatus 1 of this embodiment performs image processing quickly and appropriately on image data exceeding the line width of the line buffer Lb of the image processing device 4.

  When an operation for instructing the start of copying or data transfer is performed on the operation display unit after a document is set on the reading unit 2 and necessary operations are performed on the operation display unit, the copying unit 1 Then, the image data of the original is read and the read image data of the original is written (written) into the RAM 3 line by line as write data W1 to W3 as shown in FIG.

  When the line width of the image data written in the RAM 3 is equal to or smaller than the line width of the built-in line buffer Lb, the image processing device 4 reads the image data in the RAM 3 for each line and writes it in the line buffer Lb. Necessary image processing is performed on the image data in the line buffer Lb, and the image processed image data is output to the controller as it is. The controller converts the image data sent from the image processing device 4 into image data necessary for printing out by the printer unit, sends the image data to the printer unit, and prints it out by the printer unit or transfers it to an external device. The image data is converted into image data suitable for the transfer to the external device via the network connection unit.

  On the other hand, when the line width of the image data written in the RAM 3 is larger than the line width of the built-in line buffer Lb, the image processing device 4 converts the image data on the RAM 3 into a horizontal area having a predetermined number of lines in the horizontal direction. And dividing the horizontal region into a plurality of vertical regions with a predetermined line width equal to or smaller than the line width of the line buffer Lb in the vertical direction, and for each horizontal region, out of the vertical regions belonging to the horizontal region The image data in the vertical area at the top in the direction is sequentially taken from the first line into the line buffer Lb, and the image data in the line buffer Lb is converted into image data necessary for printing out by the printer unit and sent to the printer unit. The image data can be converted to image data suitable for printing on the printer unit or transfer to an external device. Transferred to the external device via the network connection. For example, as shown in FIG. 3, the image processing device 4 converts the image data stored in the RAM 3 into three horizontal areas Ah (h = 1 to *, * indicates the number of lines of the image data and one horizontal area Ah. The horizontal areas Ah are divided into a plurality of vertical areas Av (v = 1 to *, with a predetermined line width equal to or smaller than the line width of the line buffer Lb in the vertical direction. * Is a numerical value determined by the line width of the image data, the line width of the line buffer Lb, and the divided line width.) For each horizontal area Ah, among the vertical areas Av belonging to the horizontal area Ah, The image data of the head line in the vertical area Av (v = 1) on the head side in the line direction is sequentially transferred to the line buffer Lb. That is, in the case of FIG. 3, the image processing device 4 divides the image data in the RAM 3 into two horizontal areas Ah (h = 1, 2) each having a predetermined number of lines, and each horizontal area Ah (h = 1, 2) is divided into two vertical areas Av (v = 1, 2) with a line width equal to or smaller than the line width of the line buffer Lb in the vertical direction, and the horizontal area Ah is divided for each horizontal area Ah (h = 1, 2). Of the two vertical areas Av (v = 1, 2) belonging to (h = 1, 2), the image data of the vertical area Av (v = 1) on the head side in the line direction is sequentially transferred to the line buffer Lb. That is, as shown in FIG. 3 and FIG. 4 showing a more detailed procedure, the image processing device 4 performs a line image of the area A1-1 that is the vertical area Av (v = 1) of the horizontal area Ah (h = 1). Reading is started from the data R1, the line image data R2 and R3 in the area A1-1 are sequentially read and taken into the line buffer Lb, image processing is performed, and then the vertical area Av of the horizontal area Ah (h = 1). The line image data R4 to line image data R6 in the area A1-2 where (v = 2) are sequentially read and taken into the line buffer Lb to perform image processing. When the image processing device 4 completes the fetching of the line image data R1 to R6 into the line buffer Lb in all the vertical areas Av (v = 1, 2) in the horizontal area Ah (h = 1), The line image data R7 of the area A2-1 which is the vertical area Av (v = 1) of the horizontal area Ah (h = 2) is read in the same manner as described above, taken into the line buffer Lb, and image processing is sequentially performed.

  Then, the image processing device 4 sequentially processes the image data captured in the line buffer Lb for each line, combines the image data after image processing in accordance with the arrangement order of the image data on the RAM 3, and outputs the combined image data to the controller. .

  The controller temporarily stores the image data processed by the image processing device 4 in a hard disk or the like, and sends it to the printer unit to form an image on the paper in the printer unit, or to an image on an external device on the network via the network connection unit. Transfer data.

  Note that the image processing executed by the image processing device 4 in the copying apparatus 1 includes image processing that performs image processing with reference to image data of other lines, such as filter processing and gradation processing. In order to execute image processing to be processed with reference to image data of other lines, as shown in FIG. 5, for example, when two-dimensional filter processing is performed with reference to 5 lines, a line buffer Lb for 5 lines The N-1 line input image data from the N-5 line input image data is sequentially input to the line buffer Lb of the buffer Lb0 to the buffer Lb4 for each line, and the N-1 line of the last line is input. In order to perform the two-dimensional filter processing, image data of other lines is referred to.

  When performing image processing with reference to image data of such other lines, it may be necessary to perform other processing during the image processing. In such a case, the image processing device 4 installs another memory such as the RAM 3 so that the interrupted image processing can be resumed immediately after the other processing is completed. As intermediate data storage means, the RAM 3 stores the data necessary for interrupting and resuming the image processing being executed as intermediate data, and when the other processing is completed, the interrupted image processing is continued with reference to the intermediate data. To do.

  That is, when performing image processing, for example, two-dimensional filter processing, with reference to image data of another line, the copying apparatus 1 initializes the RAM 3 and the image processing device 4 and then performs the processing shown in FIG. In addition, when the image data of all the lines in the first horizontal area Ah (h = 1) composed of a plurality of lines is read line by line from the reading unit 2 and written to the RAM 3, the image processing device 4 starts with the RAM 3, The image data of the first vertical area Av (v = 1) in the horizontal area Ah (h = 1) is sequentially read for each line and, for example, sequentially written in the line buffer Lb for 5 lines as shown in FIG. Then, filter processing is executed with reference to the image data of other lines (S1).

  That is, as shown in FIG. 7, the image processing device 4 starts the image processing of the area A1-1 (the area of the vertical area Av (v = 1) of the horizontal area Ah (h = 1)) and the image processing is performed. When completed, all the intermediate data C1 is written to the RAM 3 (S2), and processing of the area A1-2 (the area of the vertical area Av (v = 2) of the horizontal area Ah (h = 1)) as shown in FIG. (S3). Further, when the processing of the area A1-2 is completed, the image processing device 4 writes all the intermediate data C2 to the RAM 3 (S3), and as shown in FIG. 8, the area 2-1 (horizontal area Ah (h = 2) ) (Vertical region Av (v = 1) region) (S5, S6). At this time, as shown in FIG. 8, the image processing device 4 reads the intermediate data C after the processing of the area 1-1 (S5), starts the processing of the area 2-1 (S6), and the area 2 When the process of −1 is completed, all the intermediate data C is written to the RAM 3 (S7), and the process proceeds to the process of the area 2-2 (the area of the vertical area Av (v = 2) of the horizontal area Ah (h = 2)). . In the process of the area 2-2, the image processing device 4 reads the intermediate data after the process of the area 1-2, starts the process of the area 2-2, and ends the process of the area 2-2. Then, all the intermediate data is written to the RAM 3, and the processing of the area 3-1 (the area of the vertical area Av (v = 1) of the horizontal area Ah (h = 3)) is started. In the process of the area 3-1, the image processing device 4 reads the intermediate data after the process of the area 2-1, and then starts the process of the area 3-1. The process of writing to the RAM 3 and shifting to the process of the area 3-2 (the area of the vertical area Av (v = 2) of the horizontal area Ah (h = 3)) is repeatedly performed, and the process for one page is performed.

  That is, the processing of the area A1-2 is started after the processing of the area A1-1 is completed, but the reading unit 2 has finished reading the area A1-1 and the area A1-2 because the horizontal division is also performed. At that time, the image processing of the area A1-2 can be started. Similarly, in the case of FIG. 4, the area where the image processing is not finished when the reading unit 2 finishes reading the entire area Ah-v is only the area A3-2, and the processing time is increased due to the area division. The minute is only the last one area divided in the horizontal direction and the vertical direction, and an increase in processing time due to the area division can be greatly reduced.

  In short, the image is divided in the horizontal direction and the vertical direction, and the processing is finished in the division unit in the horizontal direction. Therefore, by increasing the processing speed of the image processing device 4, the horizontal area Ah can be read at a constant speed. Image processing can be performed, and image processing can be performed at a speed close to real-time processing.

  As described above, when image processing is performed while referring to the reference data, the intermediate data C is written to the RAM 3, the intermediate data C is read from the RAM 3, and the region ( By returning to the state after completion of the image processing of h-1) -v, the same result as when the region hv and the region (h-1) -v are processed in succession can be obtained.

  Then, when the image processing device 4 performs image processing on the image data divided in the horizontal direction and the vertical direction, the image processing device 4 combines them with the image data before division and outputs the combined image data to the controller.

  That is, as shown in FIG. 5, the image processing device 4 includes line buffers Lb corresponding to the number of lines referred to in the image processing. When the line data is updated, the line data of all the line buffers Lb are also updated. Shift one line. Specifically, at the time of line update, the line data of the line buffer Lb1 is copied to the line buffer Lb0, the line data of the line buffer Lb2 is copied to the line buffer Lb1, the line data of the line buffer Lb3 is copied to the line buffer Lb2, and the line buffer The line data of Lb4 is copied to the line buffer Lb3, sequentially copied, and two-dimensional filter processing is performed by referring to the data of several consecutive lines.

  That is, when the image data is divided in the vertical direction according to the line width of the line buffer Lb, the same image processing result as in the case where the image data is divided in the horizontal direction to increase the processing speed and is not divided in the horizontal direction. Can be obtained.

  In addition, the image processing device 4 performs processing other than processing involving reference to other continuous line data, such as performing other processing of another region of the image in the middle of filter processing, for example, another region. When performing the filter processing, as shown in FIG. 9, in order to perform the other processing, the image data of the different region to be processed is written in the line buffer Lb, and the image processing of the different region is performed. In other words, the line buffer Lb is filled with image data from other areas to perform different processing.

  Therefore, when performing image processing of another region, the image processing device 4 converts the data of the line buffer Lb used in the image processing that refers to the plurality of line buffers Lb, for example, filter processing up to the intermediate data C As shown in FIG. 10, when the other processes are completed and the filter process is resumed by writing and storing in the RAM 3, the intermediate data in the RAM 3 is referred to as shown in FIG. And the filtering process can be resumed appropriately. In this case, the intermediate data C is a line buffer Lb, a register such as a counter, and all other data used in image processing. In FIG. 10, the processing is interrupted after the five-line reference two-dimensional filter processing of the (N−1) -th line in FIG. 5, and the image data of the other region shown in FIG. 9 is entered in the line buffer Lb. Later, the case of resuming the five-line reference two-dimensional filter processing of the N-th line is shown.

  In the above description, the case where the filtering process is performed with reference to five lines has been described. However, the image processing that is performed with reference to a plurality of line data is not limited to the filtering process, and the number of lines is also determined. The present invention is not limited to five lines, and by applying to general image processing that performs calculations using line buffers Lb for a plurality of lines, the image processing can be interrupted and resumed promptly and appropriately.

  Further, for example, even in the image processing in which two types of operations are alternately switched for each line, the information indicating whether the current line is an even line or an odd line is stored as intermediate data C, thereby interrupting the process. By reading the intermediate data C, the continuity can be maintained promptly and appropriately.

  Thus, by writing all the line buffer Lb and internal information used in the image processing to the RAM 3 as intermediate data, the processing can be interrupted and resumed quickly and appropriately, and the line width of the line buffer Lb Thus, even if the image data is divided in the vertical direction, it can be processed appropriately and promptly.

  For example, as shown in FIG. 11 as intermediate data for high image quality, the intermediate data C includes all the data in the line buffer Lb used in each image processing (printer processing, gradation processing, etc.) and information in the internal register. In this case, interruption and resumption can be performed promptly and appropriately in all image processing.

  However, the writing of the intermediate data to the RAM 3 is not limited to the case of writing all the processing data as described above, and the data used as the intermediate data C according to the image quality requirements required in the image processing, For example, as shown as intermediate data for high-speed processing in FIG. 12, only the filter internal register data and the gradation processing internal register data may be written as intermediate data C in the RAM 3. In this way, the capacity of the RAM 3 used for the intermediate data C can be saved, and the processing time can be further increased by reducing the time for writing and reading the intermediate data C to the RAM 3. .

  As described above, when the line width of the image data of the processing target image read by the reading unit 2 and stored in the RAM 3 is larger than the line width of the line buffer Lb, the copying apparatus 1 of the present embodiment has the image processing device 4. The image data is divided into horizontal areas Ah for each predetermined number of lines in the horizontal direction, and the horizontal areas Ah are divided into a plurality of vertical areas Av with a predetermined line width equal to or smaller than the line width of the line buffer Lb in the vertical direction. The image data is divided and transferred to the line buffer Lb sequentially from the image data of the vertical area Av on the head side in the line direction among the vertical areas Av belonging to the horizontal area Ah for each horizontal area Ah. Predetermined image processing is performed on the image data, and the image data processed for each vertical area Av is combined with the image data of the processing target image. To have.

  Therefore, image data having an image width exceeding the line width of the line buffer Lb can be promptly processed without increasing the circuit scale.

  In addition, the copying apparatus 1 according to the present exemplary embodiment is configured to perform image processing such as filter processing and gradation processing by referring to image data of other lines stored in a line buffer Lb in which image data for a plurality of lines is stored. When the processing is interrupted and other image processing is executed, data necessary for interrupting and resuming the image processing being executed is stored as intermediate data C in a RAM (intermediate data storage means) 3.

  Therefore, even if the execution of the image processing to be processed with reference to another line such as file processing is interrupted and another processing is executed, the continuity of the processing is maintained based on the intermediate data, and the original processing is promptly performed. Image processing can be continued, and the speed of image processing can be increased.

  Further, the copying apparatus 1 of this embodiment appropriately selects the intermediate data C stored in the RAM 3.

  Therefore, it is possible to process according to the user's intention among the improvement of the image quality and the increase of the processing speed while reducing the capacity used for the intermediate data C of the RAM 3, and the usability can be improved. it can.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  The present invention can be used in an image processing apparatus, an image forming apparatus, an image processing method, an image processing program, and a recording medium that perform image processing on image data having a line width exceeding the line buffer width.

1 Copier 2 Reading unit 3 RAM
4 Image processing unit Ah Horizontal area Av Vertical area Lb Line buffer

JP 2006-186717 A

Claims (7)

A line buffer having a predetermined line width in which image data is sequentially stored in a predetermined line direction in units of lines;
When the line width of the image data of the processing target image is larger than the line width of the line buffer, the image data is divided into horizontal areas for each predetermined number of lines in the horizontal direction, and the horizontal area is divided into the lines in the vertical direction. The line is divided into a plurality of vertical areas with a predetermined line width equal to or smaller than the line width of the buffer, and the lines are sequentially started from the image data of the vertical area on the leading side in the line direction among the vertical areas belonging to the horizontal area for each horizontal area. Data management means for transferring to the buffer;
Image processing means for performing predetermined image processing on the image data transferred to the line buffer;
Image data combining means for combining image data processed by the image processing means for each vertical region in accordance with image data of the processing target image;
An image processing apparatus comprising: The image processing apparatus includes:
An intermediate data storage means for storing the intermediate data;
The line buffer is
It has a buffer for multiple lines,
The image processing means includes
Data required for interrupting and resuming the image processing being executed when the image processing to be processed with reference to the image data of another line stored in the line buffer is interrupted and another image processing is executed The image processing apparatus according to claim 1, wherein the intermediate data is stored in the intermediate data storage unit. The image processing means includes
3. The image processing apparatus according to claim 1, wherein the intermediate data to be stored in the intermediate data storage unit is appropriately selected.   An image forming apparatus comprising the image processing apparatus according to claim 1. When the line width of the image data of the processing target image is larger than the line width of the line buffer, the image data is divided into horizontal areas for each predetermined number of lines in the horizontal direction, and the horizontal area is divided into the line buffer in the vertical direction. Are divided into a plurality of vertical areas with a predetermined line width equal to or less than the line width of the vertical areas, and the line buffer sequentially from the image data of the vertical area on the leading side in the predetermined line direction among the vertical areas belonging to the horizontal area for each horizontal area Data management processing steps to be transferred to
An image processing step of performing predetermined image processing on the image data transferred to the line buffer;
An image data combination processing step for combining the image data image-processed for each vertical region in the image processing step according to the image data of the processing target image;
An image processing method characterized by comprising: On the computer,
When the line width of the image data of the processing target image is larger than the line width of the line buffer, the image data is divided into horizontal areas for each predetermined number of lines in the horizontal direction, and the horizontal area is divided into the line buffer in the vertical direction. Are divided into a plurality of vertical areas with a predetermined line width equal to or less than the line width of the vertical areas, and the line buffer sequentially from the image data of the vertical area on the leading side in the predetermined line direction among the vertical areas belonging to the horizontal area for each horizontal area Data management process to transfer to
Image processing for performing predetermined image processing on the image data transferred to the line buffer;
Image data combining processing for combining image data processed for each vertical region in the image processing in accordance with image data of the processing target image;
An image processing program for executing   A computer-readable recording medium on which the image processing program according to claim 6 is recorded.

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