JP2007280194A - Image processor, image forming apparatus, and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor capable of improving throughput by preventing processing interruption caused by no presence of an empty area in which memory addresses continue, which are necessary to store processed image data when the arrangement of image data in a storage area is not appropriate, and to provide an image forming apparatus provided with the image processor, and an image processing method. <P>SOLUTION: An image memory control part transfers compressed data of (N+1)th page from a storage part to an image memory before the processing of N-th page is finished (image memory clearance) when it is determined that determination processing satisfies a relation of (M-S1)/2≥S2. The image memory control part reads the stored compressed data, decompresses the compressed data and stores (arranges) the decompressed data in the image memory when the processing of the N-th page is finished (image memory clearance). The stored decompressed data are read, and the read decompressed data are transferred from the image memory to a printing processing part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image processing device that stores together image data and post-processing image data obtained by performing predetermined processing on the image data in a predetermined storage area, an image forming apparatus including the image processing device, and image processing Regarding the method.

  In recent years, with the speeding up of information processing represented by the Internet or the increase in the amount of information, digital multifunction devices installed in offices have created documents and drawings in addition to processing such as faxing, printing, and copying. It is also equipped with a function such as a document file processing for filed in a database and is shared by many users, and a large amount of image data is processed at high speed.

  Conventionally, in a digital multi-function peripheral, a semiconductor memory that can be accessed at high speed is used as a primary storage device (image memory), and a hard disk drive (HDD) that has a relatively low access time is configured as a secondary storage device. When the image data acquired by reading is compressed and the compressed image data is stored in the HDD and image formation (printing processing) is performed, the compressed image data stored in the HDD is stored in a predetermined storage area of the image memory. In addition to storing (buffering), the compressed image data is decompressed, and the decompressed image data is stored (buffered) in the storage area and transferred to the print processing unit, thereby sharing the storage area. The required processing was performed in parallel.

  When sharing different data such as compressed image data and decompressed image data in a common storage area, it is necessary to allocate a memory area for each different data, and if the allocated memory area is not occupied by data, the storage area There is a possibility that a discontinuous empty area (fragmentation) occurs in the memory, and the use efficiency of the memory is lowered, and the processing may be interrupted due to a memory shortage. When the storage area is shared by different data, a so-called deadlock may occur depending on the arrangement of the data in the storage area, and the processing may be interrupted.

  As an example of preventing fragmentation, a continuous area on the memory is divided in advance into a first partition and a second partition, and the first of the free areas in the second partition is used to store data. When the memory area closest to the partition is allocated and the data processing is completed and the memory area becomes unnecessary, the allocated memory area is released, and the released memory area is included in the first partition. In addition, a data processing apparatus that does not generate fragmentation by changing the division between the first partition and the second partition has been proposed (see Patent Document 1).

  As an example of preventing deadlock, when image formation (printing processing) is performed, when processing is performed by buffering compressed image data and decompressed image data in a storage area, processing for one page is performed. There is a digital multi-function peripheral that prevents deadlock by releasing (clearing) the storage area when the process is completed and then processing the next page.

  FIG. 11 is a time chart showing the processing procedure of the conventional digital multifunction peripheral, and FIG. 12 is a time chart showing the data arrangement of the image memory of the conventional digital multifunction peripheral. As illustrated in FIG. 11, for example, when printing the Nth page, the digital multifunction peripheral transfers the compressed data from the storage unit (HDD) to the image memory. Thereby, the compressed data is stored (arranged) in the image memory. Next, the stored compressed data is read out, the compressed data is decompressed, and the decompressed data is stored (arranged) in the image memory. The stored decompressed data is read, and the read decompressed data is transferred from the image memory to the print processing unit. When the transfer process ends, the stored compressed data and decompressed data are cleared and the image memory is released. After the image memory is released, the processing for the next page (N + 1 page) is continued in the same manner.

As shown in FIG. 12, the N page compressed data S1 (N) is first stored in the shared area (shared memory) of the image memory. Next, decompressed data S2 (N) of the Nth page obtained by decompressing the compressed data S1 (N) is stored. After the decompressed data S2 (N) is transferred from the image memory to the print processing unit, the shared memory is cleared (released). Thereafter, similarly, the compressed data S1 (N + 1) of the (N + 1) th page is stored, and the expanded data S2 (N + 1) of the (N + 1) th page obtained by expanding the compressed data S1 (N + 1) is stored.
JP 2002-351739 A

  However, in the example of Patent Document 1, complicated memory management is necessary because a process of reallocating a partition according to a process of securing a memory according to a request and a process of releasing a memory that becomes unnecessary is performed. It becomes. For this reason, there has been a demand for a digital multi-function peripheral that can prevent processing from being interrupted due to insufficient memory by simple means.

  Further, in the conventional example as shown in FIGS. 11 and 12, since the processing of each page is performed in series, the compressed data S1 (N + 1) and the decompressed data S2 (N + 1) of the (N + 1) th page are stored. The storage area that has already stored the compressed data S1 (N) and the decompressed data S2 (N) of the Nth page has been cleared, and the storage position (for example, compressed data S1 (N + 1)) in the storage area ( Regardless of the arrangement, post-processing image data, for example, decompressed data S2 (N + 1) can be stored, and deadlock can be prevented. However, the processing speed of the entire apparatus is reduced. For this reason, there has been a demand for a digital multi-function peripheral that can improve the processing capability of the entire apparatus without interruption of processing due to deadlock.

  The present invention has been made in view of such circumstances, and the amount of data of each of image data stored together in a predetermined storage area and post-processing image data obtained by performing predetermined processing on the image data. By calculating, setting the address for storing the image data based on the calculated data amount and the storage capacity of the storage area, and storing the image data based on the set address, It is possible to improve processing performance by preventing interruption of processing due to the absence of an empty area with continuous memory addresses necessary for storing post-processing image data when the arrangement of image data in the storage area is inappropriate. An object is to provide an image processing apparatus, an image forming apparatus including the image processing apparatus, and an image processing method.

  Another object of the present invention is to store the data in the storage area when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M satisfy the relationship of (M−S1) / 2 ≧ S2. By setting the address of the image data in the usable area, the address for storing the image data can be set with a simple configuration without waiting until the entire storage area is cleared (released). Another object of the present invention is to provide an image processing apparatus capable of improving the processing capability and an image forming apparatus including the image processing apparatus.

  Another object of the present invention is released when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M do not satisfy the relationship of (M−S1) / 2 ≧ S2. An image processing apparatus capable of preventing interruption of processing with a simple configuration by setting an address of the image data on the upper address side or lower address side of the storage area, and an image forming apparatus including the image processing apparatus It is to provide.

  Another object of the present invention is a data amount S1 of image data stored together in a predetermined storage area, a data amount S2 of post-processing image data obtained by performing predetermined processing on the image data, and a predetermined amount When the storage capacity M of the storage area satisfies the relationship (M−S1) / 2 ≧ S2, an address for storing image data is set in the specified usable area, and the image data is stored. If the storage area other than the storage area storing the image data is released, the processed image data is stored, and if the relationship of (M−S1) / 2 ≧ S2 is not satisfied, the predetermined storage is performed. When the area is released, an address for storing image data is set on the upper address side or lower address side of the storage area, and when the image data is stored, other than the storage area storing the image data By storing the processed image data in the storage area, there is no empty area with continuous memory addresses necessary for storing the processed image data when the arrangement of the image data in the storage area is inappropriate with a simple configuration. It is an object of the present invention to provide an image processing apparatus and an image forming apparatus including the image processing apparatus that can improve processing performance by preventing interruption of processing due to the above.

  Another object of the present invention is that the image data is compressed image data, and the processed image data is image data obtained by decompressing the compressed image data. An image processing apparatus capable of preventing processing interruption due to the absence of a free area having continuous memory addresses, which is necessary for storing decompressed image data when the layout of the image data is inappropriate, and improving processing performance An object of the present invention is to provide an image forming apparatus including the image processing apparatus.

  An image processing apparatus according to the present invention calculates a data amount of image data in an image processing apparatus that stores image data and processed image data obtained by performing predetermined processing on the image data together in a predetermined storage area. Based on the first calculation means, the second calculation means for calculating the data amount of the processed image data, the data amounts calculated by the first calculation means and the second calculation means, and the storage capacity of the storage area. And setting means for setting an address for storing the image data, and the image data is stored based on the address set by the setting means.

  The image processing apparatus according to the present invention includes means for specifying a usable area among the storage areas, and the setting means includes a data amount S1 of image data, a data amount S2 of post-processing image data, and the storage capacity. When M satisfies the relationship of (M−S1) / 2 ≧ S2, an address is set in the area specified by the means.

  The image processing apparatus according to the present invention further comprises means for releasing the storage area, and the setting means is a higher rank of the storage area released by the means when the relationship of (M−S1) / 2 ≧ S2 is not satisfied. An address is set on the address side or the lower address side.

  An image processing apparatus according to the present invention calculates a data amount of image data in an image processing apparatus that stores image data and processed image data obtained by performing predetermined processing on the image data together in a predetermined storage area. Based on the first calculation means, the second calculation means for calculating the data amount of the processed image data, the data amounts calculated by the first calculation means and the second calculation means, and the storage capacity of the storage area. , Setting means for setting an address for storing the image data, means for specifying an available area of the storage area, and means for releasing the storage area, wherein the setting means includes image data When the data amount S1, the data amount S2 of the processed image data, and the storage capacity M satisfy the relationship of (M−S1) / 2 ≧ S2, the image data is stored in the specified area. When the image data is stored, when the storage area other than the storage area storing the image data is released, the processed image data is stored. In addition, when the relationship of (M−S1) / 2 ≧ S2 is not satisfied, the setting means sends the image data to the upper address side or the lower address side of the storage area when the predetermined storage area is released. An address for storage is set, and when the image data is stored, the processed image data is stored in a storage area other than the storage area for storing the image data. It is characterized by that.

  In the image processing apparatus according to the present invention, the image data is compressed image data, and the processed image data is image data obtained by decompressing the compressed image data.

  An image forming apparatus according to the present invention includes any one of the above-described image processing apparatuses of the present invention and an image forming unit that forms an image based on image data processed by the image processing apparatus. Features.

  An image processing method according to the present invention calculates an amount of image data in an image processing method in which image data and post-processing image data obtained by performing predetermined processing on the image data are stored together in a predetermined storage area. And calculating the data amount of the processed image data, and setting an address for storing the image data based on the calculated image data and the data amount of the processed image data, and the storage capacity of the storage area. The image data is stored based on the set address.

  In the present invention, for example, the predetermined storage area is a storage that can store image data for one page of a document and post-processing image data obtained by performing predetermined processing on the image data. Have capacity. When storing the image data of the (N + 1) th page and the processed image data in the storage area, the data amounts of the (N + 1) th page of image data and the processed image data are calculated, and based on the calculated data amounts and the storage capacity of the storage area, respectively. Then, an address for storing the image data is set. For example, when the image data of the (N + 1) th page is stored in the unused area of the storage area in a state where the image data of the Nth page and the processed image data are stored in the storage area, the calculated data amount and the storage area are stored. Based on the capacity, it is determined whether the processed image data of the (N + 1) th page can be arranged in the storage area together with the image data of the (N + 1) th page. If it is determined that the processed image data of the (N + 1) th page can be arranged in the storage area, an address is set so that the image data of the (N + 1) th page is stored in the unused area. Thus, the image data of the (N + 1) th page is stored without waiting until the area occupied by the image data of the Nth page and the processed image data is released, and a predetermined process is performed based on the stored image data.

  Further, when it is determined that the processed image data of the (N + 1) th page cannot be arranged in the storage area, the area occupied by the Nth page of image data and the processed image data is released (cleared), and then the (N + 1) th page. An address is set so that the image data is stored in the storage area. Thus, when the image data of the (N + 1) th page is stored, the process is prevented from being interrupted without causing a deadlock when the processed image data of the (N + 1) th page is stored.

  In the present invention, when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M satisfy the relationship of (M−S1) / 2 ≧ S2, the storage area can be used. The address of the image data is set in a proper area. For example, when the data amount of the image data of the (N + 1) th page is S1 and the data amount of the processed image data of the (N + 1) th page is S2, when the relationship of (M−S1) / 2 ≧ S2 is satisfied, the N + 1th page Regardless of the arrangement (storage position) of the image data in the storage area, it is possible to arrange the processed image data of the (N + 1) th page in the storage area. As a result, it is not necessary to wait for the area occupied by the image data and / or processed image data of the Nth page to be released (cleared), but occupied by the image data and / or processed image data of the Nth page. Even when the image data of the (N + 1) th page is stored at an arbitrary address of the unoccupied area that has not been processed, the processed image data of the (N + 1) th page can be stored without causing a deadlock.

  In the present invention, when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M do not satisfy the relationship of (M−S1) / 2 ≧ S2, the released storage area An address is set on the upper address side or the lower address side. For example, when the data amount of the image data of the (N + 1) th page is S1 and the data amount of the processed image data of the (N + 1) th page is S2, when the relationship of (M−S1) / 2 ≧ S2 is not satisfied, the N + 1th page Depending on the arrangement (storage position) of the image data in the storage area, the processed image data of the (N + 1) th page cannot be arranged in the storage area, which may cause a deadlock. Waiting for the area occupied by the image data of the Nth page and / or the processed image data to be released (cleared), the upper address side or the lower address side of the storage area where the image data of the (N + 1) th page is released The post-processing image data of the (N + 1) th page can be stored without causing a deadlock.

  In the present invention, when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M satisfy the relationship of (M−S1) / 2 ≧ S2, the image is displayed in the specified region. Set an address to store data. When the image data is stored at the set address, the processed image data is stored when the storage area other than the storage area storing the image data is released. For example, when the data amount of the image data of the (N + 1) th page is S1 and the data amount of the processed image data of the (N + 1) th page is S2, when the relationship of (M−S1) / 2 ≧ S2 is satisfied, the N + 1th page Regardless of the arrangement (storage position) of the image data in the storage area, it is possible to arrange the processed image data of the (N + 1) th page in the storage area without causing a deadlock. As a result, it is not necessary to wait for the area occupied by the image data and / or processed image data of the Nth page to be released (cleared), but occupied by the image data and / or processed image data of the Nth page. When the image data of the (N + 1) th page is stored in an arbitrary address of the unoccupied area that is not yet stored, and the image data of the (N + 1) th page is stored, it is occupied by the image data of the Nth page and / or the processed image data. When the area is released (cleared), the attribute data of the (N + 1) th page is stored.

  Further, when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M do not satisfy the relationship of (M−S1) / 2 ≧ S2, when a predetermined storage area is released When an address for storing image data is set on the upper address side or lower address side of the storage area and the image data is stored, the processed image data is stored in a storage area other than the storage area storing the image data. Remember. For example, when the data amount of the image data of the (N + 1) th page is S1 and the data amount of the processed image data of the (N + 1) th page is S2, when the relationship of (M−S1) / 2 ≧ S2 is not satisfied, the N + 1th page Depending on the arrangement (storage position) of the image data in the storage area, the processed image data of the (N + 1) th page cannot be arranged in the storage area, which may cause a deadlock. Waiting for the area occupied by the image data of the Nth page and / or the processed image data to be released (cleared), the upper address side or the lower address side of the storage area where the image data of the (N + 1) th page is released The post-processing image data is stored in a storage area other than the storage area storing the image data, so that the post-processing image data of the (N + 1) th page can be stored without causing a deadlock.

  In the present invention, the image data is compressed image data, and the post-processing image data is image data obtained by decompressing the compressed image data, so that the arrangement of the compressed image data in the storage area is reduced. The processing is prevented from being interrupted due to the fact that there is no free space with consecutive memory addresses necessary for storing the decompressed image data when it is inappropriate.

  In the present invention, the amount of image data stored together in a predetermined storage area and the amount of processed image data obtained by performing predetermined processing on the image data are calculated. In addition, an address for storing the image data is set on the basis of the storage capacity of the storage area, and the image data is stored on the basis of the set address. The processing capability can be improved by preventing the interruption of the processing due to the absence of the free space where the memory addresses are continuous, which is necessary for storing the processed image data when appropriate.

  In the present invention, when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M satisfy the relationship of (M−S1) / 2 ≧ S2, the storage area can be used. By setting the address of the image data in an area, it is possible to set the address for storing the image data with a simple configuration without waiting until the storage area is completely cleared (released). While preventing interruption, the processing capability can be improved.

  In the present invention, when the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M do not satisfy the relationship of (M−S1) / 2 ≧ S2, the released storage area By setting the address of the image data on the higher address side or the lower address side, it is possible to prevent interruption of processing with a simple configuration.

  In the present invention, the data amount S1 of the image data stored together in the predetermined storage area, the data amount S2 of the processed image data obtained by performing the predetermined process on the image data, and the predetermined storage area If the storage capacity M satisfies the relationship of (M−S1) / 2 ≧ S2, an address for storing image data is set in the specified usable area, and when the image data is stored, When a storage area other than the storage area storing the image data is released, the post-processing image data is stored, and if a relationship of (M−S1) / 2 ≧ S2 is not satisfied, a predetermined storage area is released When the image data is stored in the upper address side or the lower address side of the storage area when the image data is stored, a storage area other than the storage area storing the image data By storing post-processing image data, if the arrangement of the image data in the storage area is inappropriate with a simple configuration, there is no need for processing due to the fact that there is no empty area with continuous memory addresses necessary for storing post-processing image data. The interruption can be prevented and the processing capacity can be improved.

  In the present invention, the image data is compressed image data, and the post-processing image data is image data obtained by decompressing the compressed image data, so that the arrangement of the compressed image data in the storage area is reduced. The processing capability can be improved by preventing the interruption of the processing due to the absence of the free space where the memory addresses are continuous, which is necessary for storing the decompressed image data when inappropriate.

  Hereinafter, a digital multi-function peripheral as an example of an image forming apparatus including an image processing apparatus according to the present invention will be described with reference to the drawings illustrating an embodiment. FIG. 1 is a block diagram showing an internal configuration of a digital multifunction peripheral 100 according to the present invention. The digital multifunction peripheral 100 includes an image processing apparatus 10, an image reading unit 30, a print processing unit 40, and the like. The image processing apparatus 10 includes an image input unit 11, an image memory control unit 12, an image processing unit 13, an image data compression unit 14, an image memory 15, a storage unit 16, a control unit 17, a ROM 18, a RAM 19, and an image data expansion unit. 20, a print image generation unit 21 and the like.

  The image reading unit 30 is, for example, an automatic document feeder (ADF), which detects a document placed on a tray by a document sensor (not shown), and moves while conveying the detected document. The reflected light from the document is photoelectrically converted into an analog signal by a CCD (not shown), and the obtained analog signal is converted into a digital signal by an A / D converter (not shown). The image reading unit 30 outputs a digital signal (image data) obtained by the conversion to the image processing apparatus 10.

  The image input unit 11 has an interface function for outputting the image data (RGB data) input from the image reading unit 30 to the image memory control unit 12.

  The image memory control unit 12 stores compressed data (compressed image data obtained by compressing image data) and expanded data (expanded image data obtained by expanding compressed image data), which will be described later, in a predetermined storage area of the image memory 15. An address designation register for designating an address for (buffering), a signal generation unit (not shown) for instructing reading and storing of data, and the like are provided.

  Further, the image memory control unit 12 includes a flag indicating whether the compressed data and / or decompressed data stored in a predetermined storage area of the image memory 15 is waiting for processing, being processed, and processed. The occupied area occupied by the compressed data and / or decompressed data that has been processed is cleared (released). This makes it possible to use the occupied area for other data. In addition, the image memory control unit 12 determines the address and size of a free area that is not occupied by compressed data and / or decompressed data in the storage area (for example, if there is a discontinuous free area, the maximum free block). Calculate (specify).

  In addition, when the image memory control unit 12 transfers the compressed data from the storage unit 16 to the image memory 15 and stores the compressed data in a predetermined storage area at the time of image formation processing, the data size of the compressed data (for example, S1) and the compressed data are Based on the data size (for example, S2) of the decompressed decompressed data and the storage capacity M of the storage area, where the compressed data is stored and at what timing is set.

  The image memory control unit 12 temporarily stores the image data input from the image input unit 11 in the image memory 15, reads the stored image data from the image memory 15, and outputs it to the image processing unit 13.

  The image processing unit 13 performs a correction process for removing various distortions generated in the illumination system, the imaging system, the imaging system, and the like of the input image data, a process for adjusting the color balance of the image data, Editing processing such as density conversion processing, magnification conversion processing, and density inversion is performed, and the processed image data is output to the image data compression unit 14.

  The image data compression unit 14 includes, for example, a JPEG data compression function, and performs data compression by irreversible compression on the image data input from the image processing unit 13. The image data compression unit 14 outputs the compressed data (compressed image data) that has been compressed to the image memory control unit 12. Note that the compression method is not limited to the JPEG method, and may be another method.

  The image memory control unit 12 stores the compressed data input from the image data compression unit 14 in the storage unit 16 (for example, a secondary storage device configured with an HDD). The image memory control unit 12 includes a calculation unit that calculates the data size (data amount) of compressed data and decompressed data described later. The image memory control unit 12 can calculate the data size of the compressed data based on the address value that the compressed data input from the image data compression unit 14 occupies the image memory 15. Further, the image memory control unit 12 calculates the data size of the decompressed data after decompression based on the address value that the image data input from the image input unit 11 occupies the image memory 15 and the data size of the compressed data. Can do. Instead of the configuration for calculating the data size, the data size of the compressed data and the decompressed data is stored in advance as a table according to the characteristics of the image data, and the data size is determined by referring to the table. The structure to do may be sufficient.

  When forming (printing) an image on recording paper based on the compressed data stored in the storage unit 16, the image memory control unit 12 reads the compressed data from the storage unit 16 and stores the read compressed data in the image memory 15. (Buffering).

  The image memory control unit 12 reads the compressed data stored in the image memory 15 and outputs the read compressed data to the image data decompression unit 20.

  The image data decompression unit 20 decompresses the compressed data input from the image memory control unit 12 and outputs decompressed decompressed data (expanded image data) to the print image generation unit 21.

  The print image generation unit 21 converts RGB data into YMCK data based on the input decompressed data, and outputs the converted YMCK data (expanded data) to the image memory control unit 12. More specifically, the print image generation unit 21 converts the RGB data into a CMYK color space, and performs color correction processing, gradation correction processing, or binarization processing according to the characteristics of the print processing unit 40 or a predetermined process. The image generation of the gradation is performed.

  The image memory control unit 12 stores the decompressed data input from the print image generating unit 21 in the image memory 15, thereby buffering the decompressed data in the image memory 15, and prints the decompressed data stored in the image memory 15. Transfer (output) to the unit 40.

  The image memory 15 is, for example, image data (for example, compressed data) necessary to form an image of one original (A4, A3, color, monochrome, etc.) and an image obtained by processing the image data. A storage area (storage capacity M) sufficient to simultaneously buffer formation data (for example, decompressed data) is determined. Thereby, both the compressed data and the decompressed data obtained by decompressing the compressed data are stored in a predetermined storage area of the image memory 15.

  The print processing unit 40 forms an image on a sheet based on the decompressed data input from the image processing apparatus 10, and discharges the sheet on which the image is formed. The print processing unit 40 includes, for example, a photosensitive drum, a charger that charges the photosensitive drum to a predetermined potential, a laser writing device that forms an electrostatic latent image on the surface of the photosensitive drum, and an electrostatic latent image on the surface of the photosensitive drum. The image forming apparatus includes a developing device that supplies toner to an image to make the image visible, and a transfer device that transfers the toner image on the surface of the photosensitive drum to a sheet (all not shown). The print processing unit 40 is not limited to the electrophotographic method, and may be any method such as an ink jet method or a thermal transfer method.

  The control unit 17 is composed of, for example, a microcomputer, and controls the entire processing of the image processing apparatus 10. That is, the control unit 17 loads the control program indicating its own control procedure stored in the ROM 18 into the RAM 19, thereby controlling the operation of the image processing apparatus 10 according to the control procedure indicated by the control program.

  FIG. 2 is a conceptual diagram of address setting for storing compressed data and decompressed data. A rectangular frame in the figure indicates a predetermined storage area of the image memory 15. For example, the storage address is set so that the upper side is the upper address and the lower side is the lower address, and the storage capacity of the storage area is M. To do. When the compressed data and the compressed data size are S1, and the decompressed data and the decompressed data size obtained by decompressing the compressed data are S2, the compressed data S1 is stored when the relationship of (M−S1) / 2 ≧ S2 is satisfied. Regardless of the location in the area, the decompressed data S2 can be placed in the storage area together with the compressed data S1 (no deadlock occurs). That is, if the above relationship is satisfied, the address for storing the compressed data can be set to an arbitrary address as long as it is a free area in the storage area.

  On the other hand, when the relationship of (M−S1) / 2 ≧ S2 is not satisfied, the decompressed data S2 is arranged in the storage area together with the compressed data S1 in accordance with the position in the storage area where the compressed data S1 is arranged. Sometimes it is not possible (deadlock occurs).

  FIG. 3 is an explanatory diagram showing the state of the storage area when deadlock occurs. For example, the compressed data S1 is arranged in a substantially central portion of the storage area, and two free areas of substantially the same size, that is, a continuous free area that is both a continuous free area that is higher than S1 and a continuous free area that is lower than S1. In such a case, the size of each of these continuous free areas is smaller than the decompressed data size S2, and the decompressed data S2 cannot be placed in the storage area, resulting in deadlock.

  Therefore, when the relationship of (M−S1) / 2 ≧ S2 is not satisfied, the address for storing the compressed data S1 is set after all the storage areas are made free in advance. In this case, setting an address on the upper address side (or lower address side) of the storage area can prevent deadlock when storing the decompressed data S2.

  Next, the operation of the image processing apparatus 10 will be described. FIG. 4 is a time chart showing the processing procedure of the image memory control unit 12. When forming an image of a plurality of pages, for example, in the processing of the Nth page, the image memory control unit 12 performs a determination process for setting the address of the compressed data of the (N + 1) th page. The image memory control unit 12 transfers the compressed data of the Nth page from the storage unit (HDD) 16 to the image memory 15. As a result, the compressed data is stored (arranged) in the image memory 15. Next, the stored compressed data is read out, the compressed data is decompressed, and the decompressed data is stored (arranged) in the image memory 15. The stored decompressed data is read, and the read decompressed data is transferred from the image memory 15 to the print processing unit 40. When the transfer process ends, the occupied area occupied by the stored compressed data and decompressed data is cleared (released) (image memory clear).

  When it is determined in the determination process that the relationship of (M−S1) / 2 ≧ S2 is satisfied, the image memory control unit 12 sets the address of the compressed data of the (N + 2) th page when starting the process of the (N + 1) th page. The compressed data of the (N + 1) th page is transferred from the storage unit (HDD) 16 to the image memory 15 before the process of the Nth page is completed (image memory clear). The image memory control unit 12 reads the stored compressed data when the processing of the Nth page is completed (image memory clear), decompresses the compressed data, and stores (arranges) the decompressed data in the image memory 15. ) The stored decompressed data is read, and the read decompressed data is transferred from the image memory 15 to the print processing unit 40. When the transfer process ends, the occupied area occupied by the stored compressed data and decompressed data is cleared (released) (image memory clear). Thereby, compared with the conventional processing, the processing time of the time Td per page (see FIG. 4) can be shortened and the processing capability can be improved. The same processing is repeated for the subsequent pages.

  FIG. 5 is a time chart showing the data arrangement of the storage area of the image memory 15. As shown in the figure, in a predetermined storage area (shared memory) of the image memory 15, first, compressed data S1 (N) of the Nth page is stored. Next, decompressed data S2 (N) of the Nth page obtained by decompressing the compressed data S1 (N) is stored. When the determination process of the image memory control unit 12 determines that the relationship of (M−S1) / 2 ≧ S2 is satisfied, the compressed data of the (N + 1) th page is completed before the processing of the Nth page is completed (image memory clear). Is transferred from the storage unit (HDD) 16 to the image memory 15, so that the compressed data S1 (N + 1) of the (N + 1) th page is stored.

  When the transfer processing of the decompressed data S2 (N) of the Nth page is completed, the occupied area occupied by the stored compressed data S1 (N) and decompressed data S2 (N) is cleared (released) (image memory). clear). Thereby, only the compressed data S1 (N + 1) of the (N + 1) th page remains in the storage area. The decompressed data S2 (N + 1) of the (N + 1) th page obtained by decompressing the compressed data S1 (N + 1) is stored. In this case, the decompressed data S2 (N + 1) can be arranged together with the compressed data S1 (N + 1) regardless of the position in the storage area where the compressed data S1 (N + 1) of the (N + 1) th page is arranged. N) and the compressed data S1 (N + 1) can be stored before clearing (releasing) the occupied area occupied by the decompressed data S2 (N).

  FIG. 6 is a time chart showing the processing procedure of the image memory control unit 12. As in the case of FIG. 4, the image memory control unit 12 performs a determination process for setting the address of the compressed data of the (N + 1) th page in the process of the Nth page. The difference from the case of FIG. 4 is that the determination process determines that the relationship of (M−S1) / 2 ≧ S2 is not satisfied. In this case, the image memory control unit 12 starts the process of the (N + 1) th page when the process of the Nth page is completed (image memory is cleared). Thereby, the decompressed data of the (N + 1) th page can be stored without causing a deadlock. Note that the time chart showing the data arrangement in the storage area of the image memory 15 in this case is the same as that in FIG.

  FIG. 7 is a time chart showing the data arrangement of the storage area of the image memory 15, and FIG. 8 is a chart showing an example of each data size. 7 and 8, the data arrangement will be described in time series divided into states 1-7. Note that the storage capacity M of the storage area is, for example, 256 MB. The decompressed data is YMCK data for image formation, and is 4 bits for each color.

  In state 1, both the compressed data S1 (N-1) and the decompressed data S2 (N-1) of the N-1th page are stored, and the data size of the compressed data S1 (N-1) is 45.1 MB. The data size of S2 (N-1) is 66.4 MB.

  The compressed data S1 (N) of page N has a data size of 32.7MB, the decompressed data S2 (N) has a data size of 99.6MB, and (M-S1) / 2 is 111.7MB. Since the relationship of S1) / 2 ≧ S2 is satisfied, no deadlock occurs with the Nth page of decompressed data S2 (N) regardless of the position in the storage area where the Nth page of compressed data S1 (N) is placed. For this reason, in state 2, the compressed data S1 (N) of the Nth page is stored together with the compressed data S1 (N-1) and the decompressed data S2 (N-1) of the N-1th page. In this case, the compressed data S1 (N) of the Nth page can be arranged at an arbitrary position in the empty area.

  In state 3, after the occupied area occupied by the compressed data S1 (N-1) and the decompressed data S2 (N-1) of the (N-1) th page is cleared (released), the decompressed data S2 (N2) of the Nth page N) is stored.

  The data size of the compressed data S1 (N + 1) on page N + 1 is 70.0 MB, the data size of the decompressed data S2 (N + 1) is 132.8 MB, (M−S1) / 2 is 93.0 MB, and (M− Since the relationship of S1) / 2 ≧ S2 is not satisfied, deadlock may occur with the decompressed data S2 (N + 1) of the (N + 1) th page depending on the storage location of the compressed data S1 (N + 1) of the (N + 1) th page. For this reason, in state 4, the compressed data S1 (N + 1) of the (N + 1) th page is not stored.

  After the occupied area occupied by the Nth page compressed data S1 (N) and the decompressed data S2 (N) is cleared (released) in the state 5, the N + 1th page compressed data S1 (N + 1) and the decompressed data S2 ( N + 1) is stored. In this case, the compressed data S1 (N + 1) of the (N + 1) th page is preferably stored on the upper address side (or lower address side) of the storage area. Thereby, deadlock with the decompressed data S2 (N + 1) can be prevented.

  The data size of the compressed data S1 (N + 2) on page N + 2 is 20.2 MB, the data size of the decompressed data S2 (N + 2) is 66.4 MB, (M−S1) / 2 is 117.9 MB, and (M− Since the relationship of S1) / 2 ≧ S2 is satisfied, no deadlock occurs with the decompressed data S2 (N + 2) of the (N + 2) th page regardless of the position in the storage area where the compressed data S1 (N + 2) of the (N + 2) th page is arranged. Therefore, in state 6, the compressed data S1 (N + 2) of the (N + 2) th page is stored together with the compressed data S1 (N + 1) of the (N + 1) th page and the decompressed data S2 (N + 1).

  In state 7, after the occupied area occupied by the compressed data S1 (N + 1) and the decompressed data S2 (N + 1) of the (N + 1) th page is cleared (released), the decompressed data S2 (N + 2) of the (N + 2) th page is stored. .

  9 and 10 are flowcharts showing the processing procedure of the image memory control unit 12. The image memory control unit 12 determines whether or not there is a processing request (S11). If there is no processing request (NO in S11), the image memory control unit 12 continues the processing in step S11 and waits until there is a processing request.

  When there is a processing request (YES in S11), the image memory control unit 12 calculates the compressed data size S1 (S12), and calculates the decompressed data size S2 (S13). The image memory control unit 12 determines whether or not the relationship of (M−S1) / 2 ≧ S2 (hereinafter referred to as “determination formula”, where M is the storage capacity of the storage area) is satisfied (S14).

  When the relationship of the determination formula is satisfied (YES in S14), the image memory control unit 12 calculates the maximum free block size (S15) and determines whether the maximum free block size is equal to or larger than the compressed data size S1 (S15). S16). When the maximum free block size is not equal to or larger than the compressed data size S1 (NO in S16), the image memory control unit 12 continues the process of step S16 and waits until the maximum free block size becomes equal to or larger than the compressed data size S1.

  When the maximum free block size is equal to or larger than the compressed data size S1 (YES in S16), the image memory control unit 12 places the compressed data S1 in the storage area (S17), and calculates the maximum free block size (S18). The image memory control unit 12 determines whether or not the maximum empty block size is equal to or larger than the decompressed data size S2 (S19).

  If the maximum free block size is not equal to or greater than the decompressed data size S2 (NO in S19), the image memory control unit 12 continues the process of step S19 and waits until the maximum free block size becomes equal to or greater than the decompressed data size S2.

  If the maximum empty block size is equal to or larger than the decompressed data size S2 (YES in S19), the image memory control unit 12 places the decompressed data S2 in the storage area (S20), and determines whether or not the transfer of the decompressed data S2 is completed. Is determined (S21). If the transfer of the decompressed data S2 has not been completed (NO in S21), the image memory control unit 12 continues the process of step S21 and waits until the transfer of the decompressed data S2 is completed.

  When the transfer of the decompressed data S2 is completed (YES in S21), the image memory control unit 12 clears (releases) the occupied area occupied by the compressed data S1 and the decompressed data S2 (S22), and processes all pages. It is determined whether or not (S23). If all the pages have not been processed (NO in S23), the image memory control unit 12 continues the processing from step S12.

  If the determination formula relationship is not satisfied in step S14 (NO in S14), the image memory control unit 12 determines whether or not all the storage areas (shared memory) are free areas (S24). If all the storage areas are not free areas (NO in S24), the image memory control unit 12 continues the process of step S24 and waits until all the storage areas become free areas.

  When all the storage areas are free areas (YES in S24), the image memory control unit 12 arranges the compressed data S1 (S25), arranges the decompressed data (S26), and continues the processing from step S21. If all pages have been processed (YES in S23), the image memory control unit 12 ends the process.

  As described above, in the present invention, the data size of the compressed data stored together in the predetermined storage area and the decompressed data obtained by decompressing the compressed data are calculated, and the calculated data Setting the address for storing the compressed data based on the size and the storage capacity of the storage area, and storing the compressed data based on the set address, the placement of the compressed data in the storage area is inappropriate In such a case, it is possible to prevent the interruption of the processing due to the absence of the empty area where the memory addresses are continuous, which is necessary for storing the decompressed data, and to improve the processing capability.

  Further, when the data size S1 of the compressed data of the (N + 1) th page, the data size S2 of the decompressed data, and the storage capacity M satisfy the relationship of (M−S1) / 2 ≧ S2, the compressed data of the Nth page and / or By setting the address of the compressed data of the (N + 1) th page in the unoccupied area that is not occupied by the decompressed data, the compressed data of the (N + 1) th page is sent at an early timing without waiting until all the storage areas are cleared (released). It is possible to store the information, while preventing the occurrence of deadlock, preventing the interruption of the processing and improving the processing capability. In addition, a detection means for detecting the occurrence of a deadlock or a complicated memory management mechanism for suppressing the occurrence of a deadlock is not required, and the arrangement of data can be set with a simple configuration.

  In the above-described embodiment, the case where the compressed data and the decompressed data are shared in the storage area (shared memory) has been described. However, the data to be handled is not limited to the compressed data and the decompressed data. The present invention can also be applied to a case where two different types of data are shared and stored, such as post-processing image data obtained by performing predetermined processing on image data.

  In the above-described embodiment, the case where the compressed data and the decompressed data are stored is described from the upper address side toward the lower address side. However, the present invention is not limited to this. The configuration may be such that data is stored toward the address side.

  In the above-described embodiment, for example, the image memory control unit 12 is configured to perform the determination process for the (N + 1) th page when the process for the Nth page is started. The timing of performing is not limited to this. The determination process is not limited to being performed by the image memory control unit 12, and may be configured to be performed by another mechanism of the image processing apparatus.

  In the above-described embodiment, the case where the storage area (shared memory) is shared by the data of the Nth page and the N + 1th page has been described. However, the present invention is not limited to this, and the storage capacity of the storage area is increased. If possible, the present invention can also be applied to the case of sharing data of three pages or more.

1 is a block diagram illustrating an internal configuration of a digital multifunction peripheral according to the present invention. It is a conceptual diagram of an address setting for storing compressed data and decompressed data. It is explanatory drawing which shows the state of the storage area when a deadlock arises. It is a time chart which shows the process sequence of an image memory control part. It is a time chart which shows the data arrangement | positioning of the storage area of an image memory. It is a time chart which shows the process sequence of an image memory control part. It is a time chart which shows the data arrangement | positioning of the storage area of an image memory. It is a chart which shows the example of each data size. It is a flowchart which shows the process sequence of an image memory control part. It is a flowchart which shows the process sequence of an image memory control part. It is a time chart which shows the process sequence of the conventional digital multifunctional device. It is a time chart which shows the data arrangement | positioning of the image memory of the conventional digital compound machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image processing apparatus 11 Image input part 12 Image memory control part 13 Image processing part 14 Image data compression part 15 Image memory 16 Storage part 17 Control part 18 ROM
19 RAM
20 Image Data Expansion Unit 21 Print Image Generation Unit 30 Image Reading Unit 40 Print Processing Unit

Claims (7)

In an image processing apparatus that stores image data and processed image data obtained by performing predetermined processing on the image data together in a predetermined storage area,
First calculation means for calculating the amount of image data;
Second calculating means for calculating the data amount of the processed image data;
Setting means for setting an address for storing the image data based on the data amount calculated by the first calculation means and the second calculation means and the storage capacity of the storage area,
An image processing apparatus configured to store the image data based on an address set by the setting means. Means for specifying an available area of the storage area;
The setting means includes
If the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M satisfy the relationship (M−S1) / 2 ≧ S2, an address is set in the area specified by the means. The image processing apparatus according to claim 1, wherein the image processing apparatus is configured as described above. Means for releasing the storage area,
The setting means includes
The configuration is such that, when the relationship of (M-S1) / 2 ≧ S2 is not satisfied, an address is set on the upper address side or the lower address side of the storage area released by the means. 2. The image processing apparatus according to 2. In an image processing apparatus that stores image data and processed image data obtained by performing predetermined processing on the image data together in a predetermined storage area,
First calculation means for calculating the amount of image data;
Second calculating means for calculating the data amount of the processed image data;
Setting means for setting an address for storing the image data based on each of the data amounts calculated by the first calculation means and the second calculation means and the storage capacity of the storage area;
Means for identifying an available area of the storage area;
Means for releasing the storage area,
The setting means includes
When the data amount S1 of the image data, the data amount S2 of the processed image data, and the storage capacity M satisfy the relationship of (M−S1) / 2 ≧ S2, the image data is stored in the specified area. Configured to set the address,
When the image data is stored, it is configured to store the processed image data when a storage area other than the storage area storing the image data is released,
Further, the setting means includes
When the relationship of (M−S1) / 2 ≧ S2 is not satisfied, an address for storing image data is set on the upper address side or the lower address side of the storage area when the predetermined storage area is released. Configured
An image processing apparatus configured to store post-processing image data in a storage area other than the storage area in which the image data is stored when the image data is stored. The image data is
Compressed image data,
The processed image data is
5. The image processing apparatus according to claim 1, wherein the compressed image data is decompressed image data.   An image processing apparatus according to claim 1, and image forming means for forming an image based on image data processed by the image processing apparatus. Image forming apparatus. In an image processing method for storing together image data and post-processing image data obtained by performing predetermined processing on the image data in a predetermined storage area,
Calculate the amount of image data,
Calculate the amount of image data after processing,
Based on the calculated image data and the amount of processed image data, respectively, and the storage capacity of the storage area, an address for storing the image data is set,
An image processing method, wherein the image data is stored based on a set address.

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