JP2013138275A - Image scanning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute processing without degrading image quality when the size of image data is larger than the size of a page memory area.SOLUTION: A main control unit, when a position of writing of image data by an ASIC 14 reaches the end of a page memory area 15 before image data for one page is written in the page memory area 15, if the use of at least one of a plurality of buffer areas is ended for the image data for one page in a work memory area 13, causes the ASIC 14 to continue processing using the page memory area 15 and the buffer area whose use is ended, and if the use of none of the plurality of buffer areas is ended, causes the ASIC 14 to execute processing using an additional area secured from all or part of an area secured for another purpose in a memory 3 and the page memory area 15.

Description

  The present invention relates to an image reading apparatus.

  The image reading device optically reads a page image, generates image data of the page image, and performs predetermined processing on the image data. Image data is temporarily stored in a predetermined memory area in the middle of the process, in the preceding stage, or in the subsequent stage.

  At this time, if the size of the image data is larger than the size of a predetermined memory area, the processing is usually interrupted, but a method for continuing the processing has been proposed (see, for example, Patent Documents 1 and 2).

  In the technique described in Patent Document 1, when the size of the image data is larger than the size of the memory area, the size of the image data is reduced by increasing the compression rate of the image data.

  In the technique described in Patent Document 2, when the size of the image data is larger than the size of the memory area, the resolution of the image data is reduced to reduce the size of the image data.

JP-A-5-14562 JP 2007-174177 A

  However, reducing the size of the image data as described above is not preferable because the image quality is degraded.

  The present invention has been made in view of the above problems, and provides an image reading apparatus capable of executing processing without degrading image quality when the size of image data is larger than the size of a page memory area. For the purpose.

  In order to solve the above problems, the present invention is configured as follows.

  An image reading apparatus according to the present invention includes a scanner unit that generates and outputs image data by image reading, a plurality of data processing units, a memory that secures a work memory area and a page memory area, and a control unit. The work memory area has a plurality of buffer areas. The plurality of buffer areas are obtained by processing image data output by the scanner unit or image data obtained by performing predetermined processing on the image data output by the scanner unit, using two data processing units of the plurality of data processing units. Used in turn when handing over between departments. The page memory area is an area in which a predetermined data processing unit out of a plurality of data processing units writes image data after processing after the work memory region. When the image data writing position by the predetermined data processing unit has reached the end of the page memory area before the image data for one page is written in the page memory area, the control section can perform a plurality of image data for one page. When at least one of the buffer areas has been used, the processing by the predetermined data processing unit is continued using the page memory area and the buffer area that has been used, and a plurality of pieces of image data for one page are stored. When none of the buffer areas have been used, processing by the specified data processing unit using the additional area and page memory area secured from a part or all of the area reserved for another purpose in the memory Let it run.

  As a result, if the size of the image data is larger than the size of the page memory area, another memory area (work memory area or the above-mentioned additional area) is used in addition to the page memory area. If it is larger than the size of the area, the process can be executed without degrading the image quality. In addition, since the buffer area that has been used is preferentially additionally used, it is difficult to affect other jobs.

  In addition to the above image reading apparatus, the image reading apparatus according to the present invention may be as follows. In this case, the work memory area is continuously secured in the page memory area in the memory.

  The image reading apparatus according to the present invention may be as follows in addition to any of the image reading apparatuses described above. In this case, the control unit copies the image data in the buffer area that has not been used among the plurality of buffer areas to the next buffer area, and the predetermined data processing unit performs the work from the page memory area. Image data is continuously written to the memory area.

  As a result, when the writing position is switched from the page memory area to the work memory area, the processing can be continuously performed without interruption.

  The image reading apparatus according to the present invention may be as follows in addition to any of the image reading apparatuses described above. In this case, the control unit reduces the size of the sort memory area used for sorting the image data of the plurality of pages when the use of any of the plurality of buffer areas for the image data for one page has not been completed. The reduced area is set as the additional area described above.

  The image reading apparatus according to the present invention may be as follows in addition to any of the image reading apparatuses described above. In this case, the control unit reduces the size of the spare memory area for multi-jobs and reduces the spare memory area for multi-jobs when none of the plurality of buffer areas has been used for one page of image data. Minute is the above-mentioned additional area.

  The image reading apparatus according to the present invention may be as follows in addition to any of the image reading apparatuses described above. In this case, when the above-described additional area is secured, the control unit releases the additional area at the end of the image reading job, and returns the released area to the area secured for the above-described another use.

  This eliminates the need for a shortage of areas for the other applications described above.

  The image reading apparatus according to the present invention may be as follows in addition to any of the image reading apparatuses described above. In this case, the plurality of buffer areas described above are used as a double buffer or a ring buffer, and each of the plurality of buffer areas has a size capable of storing image data for one band.

  The image reading apparatus according to the present invention may be as follows in addition to any of the image reading apparatuses described above. In this case, the above-described work memory area is used as an input buffer for a predetermined data processing unit.

  The image reading apparatus according to the present invention may be as follows in addition to any of the image reading apparatuses described above. In this case, the predetermined data processing unit described above performs compression processing, and writes the compressed image data in the page memory area.

  In the case of compression processing, the size of the image data after the compression processing changes depending on the content of the image data. Therefore, if the size of the page memory area for storing the image data after the compression processing is set according to the minimum compression ratio, the page memory area As a result, the page memory area size can be made smaller than the size corresponding to the minimum compression ratio, thereby improving the page memory area usage efficiency.

  According to the present invention, in the image reading apparatus, when the size of the image data is larger than the size of the page memory area, the processing can be executed without degrading the image quality.

FIG. 1 is a block diagram showing a configuration of an image reading apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram for explaining various memory areas and data flow in the image reading apparatus shown in FIG. FIG. 3 is a flowchart for explaining compression processing in the image reading apparatus shown in FIG. FIG. 4 is a diagram illustrating processing when the compression processing is continued using the work memory area when the page memory area in the image reading apparatus shown in FIG. 1 is insufficient.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an image reading apparatus according to an embodiment of the present invention. The image reading apparatus shown in FIG. 1 includes a scanner unit 1, an image processing unit 2, a memory 3, a main control unit 4, and an output unit 5, which are connected to one another.

  The scanner unit 1 optically reads a page image of a document, generates image data of the page image, and outputs it.

  The image processing unit 2 performs predetermined processing on the image data. The image processing unit 2 performs predetermined processing on the image data output from the scanner unit 1 or image data obtained by performing the previous processing on the image data output by the scanner unit 1. The image processing unit 2 writes the image data after the predetermined processing into a predetermined memory area in the memory 3. For example, the image processing unit 2 includes one or a plurality of ASICs (Application Specific Integrated Circuits).

  The memory 3 is a volatile memory such as a DRAM (Dynamic Random Access Memory). In the memory 3, a memory area required for processing by the image processing unit 2 is appropriately secured.

  FIG. 2 is a block diagram for explaining various memory areas and data flow in the image reading apparatus shown in FIG.

  In FIG. 2, a CCD (Charge Coupled Device) 11 is an image sensor that outputs an optically obtained page image as an electrical signal. The reading ASIC 12 is a circuit that converts an electrical signal from the CCD 11 into image data and outputs the image data. The CCD 11 and the reading ASIC 12 are included in the scanner unit 1.

  The work memory area 13 is secured in the memory 3 and is used as an output buffer for the read ASIC 12 and an input buffer for the codec ASIC 14.

  The codec ASICs 14 and 20 are circuits that compress image data. The codec ASICs 14 and 20 compress image data by a compression method such as JPEG (Joint Photographic Experts Group).

  The primary page memory area 15 is secured in the memory 3, and the image data (compressed image data) converted by the reading ASIC 12, that is, the image data before being processed by the image processing ASIC 18 (compressed image data), It is a memory area for storing. That is, the primary page memory area 15 is an area downstream (downstream) from the work memory area 13 and is an area in which the codec ASIC 14 writes processed image data.

  The codec ASIC 16 is a circuit that decompresses the compressed image data by a decompression method corresponding to the compression method of the codec ASIC 14.

  The work memory area 17 is secured in the memory 3 and is used as an output buffer of the codec ASIC 16 and an input buffer of the image processing ASIC 18.

  The image processing ASIC 18 is a circuit that performs predetermined image processing (resolution conversion, rotation, data format conversion, etc.) on the image data.

  The work memory area 19 is secured in the memory 3 and is used as an output buffer for the image processing ASIC 18 and an input buffer for the codec ASIC 20.

  The secondary page memory area 21 is secured in the memory 3 and is a memory area for storing image data (compressed image data) after image processing by the image processing ASIC 18. That is, the secondary page memory area 21 is an area downstream (downstream) from the work memory area 19 and is an area in which the codec ASIC 20 writes processed image data.

  The codec ASICs 14, 16, and 20 and the image processing ASIC 18 are included in the image processing unit 2.

  As shown in FIG. 2, the image data output from the reading ASIC 12 is transferred to the codec ASIC 14 via the work memory area 13, and the image data compressed by the codec ASIC 14 is one band (a predetermined number of lines). They are stored in the primary page memory area 15 one by one. The codec ASIC 16 sequentially reads and expands the compressed image data stored in the primary page memory area 15 and passes the expanded image data to the image processing ASIC 18 via the work memory area 17. The image data subjected to the image processing by the image processing ASIC 18 is transferred to the codec ASIC 20 via the work memory area 19, and the image data compressed by the codec ASIC 20 is sequentially stored in the secondary page memory area 21. To go.

  Returning to FIG. 1, the main control unit 4 controls the scanner unit 1, the image processing unit 2, the memory 3, and the output unit 5. In addition, the main control unit 4 secures memory areas (work memory areas 13, 17, 19, primary page memory area 15, secondary page memory area 21 and the like) required for the image processing unit 2 in the memory 3.

  The work memory areas 13, 17, and 19 are used for transferring image data output from the scanner unit 1 or image data obtained by performing predetermined processing on the image data output from the scanner unit 1 between ASICs. Used for. The work memory areas 13, 17, and 19 have a plurality of buffer areas. The plurality of buffer areas are used as a double buffer or a ring buffer. That is, data is sequentially written in a plurality of buffer areas from the first buffer area to the last buffer area, and data is written in the first buffer area after the last buffer area. One buffer area has a size capable of storing image data for one band (image data that is not compressed and has a fixed size).

  In this embodiment, the work memory areas 13 and 19 are continuously secured in the page memory areas 15 and 21 in the memory 3, respectively.

  Further, the main control unit 4 determines that one page if the writing position of the image data by the codec ASIC 14 reaches the end of the primary page memory area 15 before the image data for one page is written in the primary page memory area 15. When at least one of the plurality of buffer areas in the work memory area 13 has been used, the processing by the codec ASIC 14 using the primary page memory area 15 and the buffer area that has been used. When one of the plurality of buffer areas has not been used for one page of image data, an additional area and a primary page secured from a part or all of the area secured for another use in the memory 3 ASIC 1 for codec using memory area 15 To perform the processing by.

  Similarly, when the image data writing position by the codec ASIC 20 reaches the end of the secondary page memory area 21 before the image data for one page is written in the secondary page memory area 21, the main control unit 4. When at least one of the plurality of buffer areas in the work memory area 19 has been used for one page of image data, the codec is used using the secondary page memory area 21 and the buffer area that has been used. If the processing by the ASIC 20 is continued and none of the plurality of buffer areas has been used for one page of image data, an addition secured from a part or all of the area reserved for another use in the memory 3 ASIC for codec using area and secondary page memory area 21 0 by executing a process.

  For example, the main control unit 4 reduces the size of the sort memory area used for sorting the image data of a plurality of pages when the use of any of the plurality of buffer areas for the image data for one page has not been completed. The decrease in the memory area is defined as the additional area described above.

  Further, for example, when the use of any of the plurality of buffer areas for one page of image data is not completed, the main control unit 4 reserves a multi-job spare memory area (when executing a plurality of jobs in parallel). The size of the memory area used) is reduced, and the reduced amount of the spare memory area for multi-jobs is set as the additional area described above.

  When the above-described additional area is secured, the main control unit 4 releases the additional area at the end of the image reading job, and returns the released area to the area secured for the above-described another use.

  When the work memory areas 13 and 19 are continuously reserved in the memory 3 in the page memory areas 15 and 21, the main control unit 4 terminates use of the buffer areas of the work memory areas 13 and 19. The image data in the buffer area that has not been copied is copied to the next buffer area, and "empty" for one buffer area is created adjacent to the page memory areas 15 and 21, and the ASICs for codecs 14 and 20 The image data is continuously written from the page memory areas 15 and 21 to the work memory areas 13 and 19 using the “vacant” space.

  The output unit 5 outputs the image data after the image processing by the image processing unit 2.

  Next, operations of the image reading apparatus (mainly the image processing unit 2 and the main control unit 4) will be described.

  Here, compression processing by the codec ASICs 14 and 20 and writing of compressed image data into the page memory areas 15 and 21 will be described. FIG. 3 is a flowchart for explaining compression processing in the image reading apparatus shown in FIG. FIG. 4 is a diagram for explaining processing when the compression processing is continued using the work memory areas 13 and 19 when the page memory areas 15 and 21 in the image reading apparatus shown in FIG. 1 are insufficient.

  The main control unit 4 secures the primary page memory area 15, sets its address information (start address and size, or start address and end address) in the codec ASICs 14 and 16, and further, as shown in FIG. As described above, the work memory area 13 is secured in succession to the primary page memory area 15, and the address information (start address and size, or start address and end address) is set in the read ASIC 12 and the codec ASIC 14. Similarly, the main control unit 4 secures the secondary page memory area 21, sets its address information (start address and size, or start address and end address) in the image processing ASIC 18, and further stores the secondary page memory. The work memory area 19 is secured continuously to the area 21 and its address information (start address and size, or start address and end address) is set in the image processing ASIC 18 and codec ASIC 20. Further, the main control unit 4 secures the work memory area 17 and sets its address information (start address and size, or start address and end address) in the codec ASIC 16 and the image processing ASIC 18.

  In the case of FIG. 4A, the read ASIC 12 uses the four buffer areas 13a to 13d in the work memory area 13 as output buffers in order, and the codec ASIC 14 uses the buffer areas 13a to 13d in order as input buffers. Use as That is, the reading ASIC 12 writes the image data for one band to the buffer area 13a, then writes the image data of the next band to the buffer area 13b, writes the image data of the next band to the buffer area 13c, and The image data of the next band is written in the buffer area 13d. Then, the reading ASIC 12 writes the image data of the next band in the buffer area 13a. On the other hand, the codec ASIC 14 reads the image data for one band from the buffer area 13a, reads the image data of the next band from the buffer area 13b, reads the image data of the next band from the buffer area 13c, and The next band of image data is read from the buffer area 13d. Then, the codec ASIC 14 reads the image data of the next band from the buffer area 13a. In this way, the work memory area 13 is used as a ring buffer by the reading ASIC 12 and the codec ASIC 14. The work memory area 19 is similarly used as a ring buffer by the image processing ASIC 18 and the codec ASIC 20.

  Next, compression processing by the codec ASIC 14 will be described.

  The codec ASIC 14 reads the image data for one band from the work memory area 13 and compresses it, and writes the compressed image data for one band in the primary page memory area 15 (step S1). At that time, the main control unit 4 counts the number of bands processed by the codec ASIC 14 for each page. At this time, the size of the image data before compression for one band is constant, but the size of the compressed image data for one band is not constant. The compressed image data of each band is continuously written in the compressed image data of the previous band without a gap. The head storage position and the end storage position (or size) of the compressed image data of each band are managed by the main control unit 4, and when the compressed image data of each band is read from the primary page memory area 15, the main control unit The read position of the compressed image data of each band is specified from the start storage position and the end storage position (or size) managed by 4.

  The codec ASIC 14 monitors whether or not the writing position of the image data has reached the end address of the primary page memory area 15 (step S2).

  When the writing of the compressed image data for one band is completed, the codec ASIC 14 determines whether or not the processing for the band for one page is completed (step S3), and the processing for the band for one page is completed. If not, the process returns to step S1 and the next band is similarly processed.

  When the codec ASIC 14 detects that the writing position of the image data has reached the end address of the primary page memory area 15, the main control unit 4 determines the number of bands processed by the codec ASIC 14 in one page. The number of remaining unprocessed bands is specified (step S4). For example, when the number of bands for one page is 75 and the count value is 72, the number of remaining bands is 3. Note that the number of bands per page is known and constant.

  Next, the main control unit 4 determines from the number of remaining bands and the number of buffer areas in the work memory area 13 whether there is a buffer area that has been used in the work memory area 13 (step S5).

  If the number of remaining bands is smaller than the number of buffer areas in the work memory area 13, it is determined that the buffer area that has been used is in the work memory area 13. Further, the value obtained by subtracting the remaining number of bands from the number of buffer areas in the work memory area 13 is the number of buffer areas that have been used.

  For example, as shown in FIG. 4B, when the number of buffer areas 13a to 13d in the work memory area 13 is 4 and the remaining number of bands is 3, there is one buffer area 13d that has been used.

  When it is determined that the buffer area that has been used is in the work memory area 13, the main control unit 4 causes the codec ASIC 14 to continue the compression process using the work memory area 13 (step S6). That is, the codec ASIC 14 is a part or all of the image data after compression processing for the band when the codec ASIC 14 detects that the writing position of the image data has reached the end address of the primary page memory area 15. In addition, the subsequent bands are written in the work memory area 13 in an area where there is no unprocessed band image data so as not to overwrite the unprocessed band image data.

  At this time, as shown in FIG. 4 (C), the main control unit 4 first images in the buffer areas 13a to 13c in use so that the buffer area 13a adjacent to the primary page memory area 15 becomes empty. Data (image data before compression processing) is moved to the next buffer area 13b-13d. That is, first, the image data in the buffer area 13c is copied to the buffer area 13d that has been used, then the image data in the buffer area 13b is copied to the buffer area 13c, and then the buffer area 13a. The image data is copied to the buffer area 13b. As a result, the buffer area 13a becomes empty.

  The codec ASIC 14 reads the subsequent bands in order from the copy destination buffer areas 13b to 13d. The compressed image data for one band generated from the image data for one band stored in the buffer area 13b of the work memory area 13 is continuously stored in the buffer area 13a from the primary page memory area 15. The When the compression processing of the image data stored in the buffer area 13b is completed by the codec ASIC 14, the buffer area 13b becomes empty, so that image data of the subsequent bands (stored in the buffer areas 13c and 13d). Compressed image data generated from (image data) is stored. Similarly, when the compression processing of the image data stored in the buffer area 13c is completed by the codec ASIC 14, the buffer area 13c becomes empty, so that image data of the subsequent bands (images stored in the buffer area 13d) Compressed image data generated from (data) is stored.

  After step S6, in step S2, the codec ASIC 14 has an image data write position in an area where there is no unprocessed band image data (the above-described “empty” buffer area). Whether or not the end has been reached is monitored, and if the writing position of the image data has reached the end of the area where there is no unprocessed band image data, the processing from step S4 onward is executed again.

  On the other hand, if there is no buffer area that has been used in the work memory area 13 (step S5), the main control unit 4 assigns a memory area for image data after compression processing for the remaining number of bands to the other memory area as described above. It is determined whether or not procurement is possible from the area reserved for the application (step S7). Note that the size of the memory area for image data after compression processing for one band is determined in advance.

  If the memory area for the image data after the compression processing for the remaining number of bands cannot be procured from the area reserved for another use as described above, the main control unit 4 gives an error notification (step S8) The compression process is stopped. For example, the main control unit 4 displays an error message on an operation panel (not shown) as an error notification.

  When the memory area for the image data after the compression processing for the remaining number of bands can be procured from the area secured for another use as described above, the main control unit 4 The specified shortage area is secured, and the secured area is added to the primary page memory area 15 (step S9).

  In the case of the codec ASIC 14, the main control unit 4 determines that there is no page data area before the compression process because there is no page memory area in the upstream (upstream side) of the codec ASIC 14 (step S <b> 1). In step S10, the main control unit 4 issues a retry notification (step S11), and stops the compression process. As the retry notification, the main control unit 4 displays a message prompting the user to perform another image scanning operation, for example, on an operation panel (not shown). As a result, the user performs the image scanning operation again, and the scanner unit 1 executes the image reading again.

  Next, compression processing by the codec ASIC 20 will be described.

  The codec ASIC 20 reads the image data for one band from the work memory area 19 and compresses it, and writes the compressed image data for one band in the secondary page memory area 21 (step S1). At that time, the main control unit 4 counts the number of bands processed by the codec ASIC 20. At this time, the size of the image data before compression for one band is constant, but the size of the compressed image data for one band is not constant. The compressed image data of each band is continuously written in the compressed image data of the previous band without a gap. The head storage position and the end storage position (or size) of the compressed image data of each band are managed by the main control unit 4, and when the compressed image data of each band is read from the secondary page memory area 21, the main control is performed. From the head storage position and end storage position (or size) managed by the unit 4, the read position of the compressed image data of each band is specified.

  The codec ASIC 20 monitors whether or not the writing position of the image data has reached the end address of the secondary page memory area 21 (step S2).

  When the writing of the compressed image data for one band is completed, the codec ASIC 20 determines whether or not the processing for the band for one page is completed (step S3), and the processing for the band for one page is completed. If not, the process returns to step S1 and the next band is similarly processed.

  When the codec ASIC 20 detects that the writing position of the image data has reached the end address of the secondary page memory area 21, the main control unit 4 determines one page from the count value of the number of bands processed by the codec ASIC 20. The number of unprocessed remaining bands at is specified (step S4).

  Next, the main control unit 4 determines from the number of remaining bands and the number of buffer areas in the work memory area 19 whether there is a buffer area that has been used in the work memory area 19 (step S5).

  If the number of remaining bands is smaller than the number of buffer areas in the work memory area 19, it is determined that the buffer area that has been used is in the work memory area 19. Further, the value obtained by subtracting the remaining number of bands from the number of buffer areas in the work memory area 19 is the number of buffer areas that have been used.

  If it is determined that the buffer area that has been used is in the work memory area 19, the main control unit 4 causes the codec ASIC 20 to continue the compression process using the work memory area 19 (step S6).

  After step S6, in step S2, the codec ASIC 20 monitors whether the writing position of the image data has reached the end of the area where there is no unprocessed band image data. When the data writing position reaches the end of the area where there is no image data of an unprocessed band, the processes after step S4 are executed again.

  On the other hand, when there is no buffer area that has been used up in the work memory area 19 (step S5), the main control unit 4 assigns a memory area for image data after compression processing for the remaining number of bands to another memory area as described above. It is determined whether or not procurement is possible from the area reserved for the application (step S7).

  If the memory area for the image data after the compression processing for the remaining number of bands cannot be procured from the area reserved for another use as described above, the main control unit 4 gives an error notification (step S8) The compression process is stopped. For example, the main control unit 4 displays an error message on an operation panel (not shown) as an error notification.

  When the memory area for the image data after the compression processing for the remaining number of bands can be procured from the area secured for another use as described above, the main control unit 4 The specified shortage area is secured, and the secured area is added to the secondary page memory area 21 (step S9).

  In the case of the codec ASIC 20, the main control unit 4 determines that the image data for one page before the compression process remains because the primary page memory area 15 exists in the previous stage (upstream side) of the codec ASIC 20. Then (step S10), the main control unit 4 performs an internal retry (step S12) and re-executes compression processing for one page. During internal retry, the main control unit 4 operates the codec ASIC 16 and the image processing ASIC 18 again to supply image data to the codec ASIC 20 again, and causes the codec ASIC 20 to execute the same processing from step S1.

  As described above, according to the above embodiment, the main control unit 4 determines that the writing position of the image data by the ASIC 14 is the end of the page memory area 15 before the image data for one page is written in the page memory area 15. When at least one of the buffer areas 13a to 13d has been used for one page of image data, the ASIC 14 uses the page memory area 15 and the buffer area that has been used. If the processing is continued and none of the plurality of buffer areas 13a to 13d has been used for one page of image data, an addition secured from a part or all of the area reserved for another use in the memory 3 Execute processing by ASIC 14 using area and page memory area 15 To.

  As a result, when the size of the image data is larger than the size of the page memory area 15, another memory area (a part of the work memory area 13 or the above-described additional area) is added to the page memory area 15. When the size of the data is larger than the size of the page memory area 15, the processing can be executed without degrading the image quality. In addition, since the buffer area that has been used is preferentially additionally used, it is difficult to additionally use a memory area for another purpose, and it is difficult for another job to be affected.

  The above-described embodiments are preferred examples of the present invention, but the present invention is not limited to these, and various modifications and changes can be made without departing from the scope of the present invention. is there.

  For example, in the above-described embodiment, the preceding process of the page memory areas 15 and 21 is the compression process, but may be another type of process.

  In the above embodiment, the buffer area that has been used in the work memory area 13 is not added to the page memory area 15 as it is, but the “free” area that continues to the page memory area 15 by using the buffer area that has been used. Instead, the buffer area that has been used may be added to the page memory area 15 and used as it is, as in the above-described additional area.

  The present invention can be applied to, for example, a scanner, a copying machine, and a multifunction machine having an image reading function.

1 Scanner unit 3 Memory 4 Main control unit (an example of control unit)
12 ASIC for reading (part of an example of multiple data processing units)
13, 19 Work memory area 13a to 13d Buffer area 14, 20 Codec ASIC (a part of an example of a plurality of data processing units, an example of a predetermined data processing unit)
15,21 page memory area 16 ASIC for codec (part of one example of multiple data processing units)
18 ASIC for image processing (part of an example of a plurality of data processing units)

Claims (9)

A scanner unit that generates and outputs image data by image reading;
A plurality of data processing units;
Image data output by the scanner unit or image data obtained by performing predetermined processing on the image data output by the scanner unit is received between two data processing units of the plurality of data processing units. A work memory area having a plurality of buffer areas that are used in order when handing over, and a page to which the predetermined data processing section of the plurality of data processing sections writes the processed image data after the work memory area A memory area is reserved, and
When the writing position of the image data by the predetermined data processing unit reaches the end of the page memory area before the image data for one page is written in the page memory area, the image data for the one page is When at least one of the plurality of buffer areas has been used, the processing by the predetermined data processing unit is continued using the page memory area and the buffer area that has been used, and the one page worth When none of the plurality of buffer areas has been used for the image data of the image data, an additional area secured from a part or all of the area secured for another use in the memory and the page memory area are used. A control unit that executes processing by the predetermined data processing unit;
An image reading apparatus comprising:   The image reading apparatus according to claim 1, wherein the work memory area is continuously secured in the page memory area in the memory. The control unit copies image data in a buffer area that has not been used among the plurality of buffer areas to the next buffer area,
The predetermined data processing unit continuously writes image data from the page memory area to the work memory area;
The image reading apparatus according to claim 2.   The control unit reduces the size of the sort memory area used for sorting the image data of a plurality of pages when none of the plurality of buffer areas has been used for the image data for one page, and the sorting is performed. 2. The image reading apparatus according to claim 1, wherein a decrease in the memory area is set as the additional area.   The control unit reduces the size of the multi-job spare memory area when the use of any of the plurality of buffer areas for the image data for one page is not finished, The image reading apparatus according to claim 1, wherein a decrease is set as the additional area.   When the additional area is secured, the control unit releases the additional area at the end of the image reading job, and returns the released area to an area secured for the other use. The image reading apparatus according to any one of claims 1 to 5.   The plurality of buffer areas are used as a double buffer or a ring buffer, and each of the plurality of buffer areas has a size capable of storing image data for one band. The image reading apparatus according to claim 1.   The image reading apparatus according to claim 1, wherein the work memory area is used as an input buffer of the predetermined data processing unit.   The image according to any one of claims 1 to 8, wherein the predetermined data processing unit performs a compression process and writes the image data after the compression process in the page memory area. Reader.

Images