JP2005176129A - Image processing method and image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing method and an image processor capable of carrying out rotation processing of image data regardless of the small-sized and inexpensive configuration of the apparatus. <P>SOLUTION: The image processor sequentially carries out operations for image data of one page. The operations comprises: expansion of the image data by one page to a page memory 10; transposition processing of writing of the image data in units of pixels, the number of which is the same in row and column directions (e.g., 8×8 pixels), from the page memory 10 to a buffer in its row direction and thereafter reading of the image data from the buffer 11 to the page memory 10 in its column direction; and writing of transposed image data after the transposition processing to original 8×8 address areas of the page memory 10. The image processor reads the transposed image data by controlling their read addresses to output the rotated image data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image processing method and an image processing apparatus for rotating image data stored in a page memory.

  In an image processing apparatus that processes image data, such as a facsimile machine, a digital copying machine, a printer, or a multifunction machine that integrates these functions, it reads image data read by itself or image data input from an external device. Some have a function of rotating 90 degrees clockwise or counterclockwise and recording on paper (see, for example, Patent Document 1). In such a rotation process of image data, when the long and short directions of the graphic drawn by the image data are made coincident with the long and short directions of the paper for easy viewing, even if there is no paper set in the predetermined direction, the direction of 90 degrees This is useful, for example, when the recording process is continued with other sheets set with different colors. During normal recording, processing for a plurality of pixels is possible with one access, but during rotational recording, only one pixel is read out with one access, and it takes time and data transfer to a printer or the like is not in time. A process for making it possible to read a plurality of pixels by access is required.

Conventionally, rotation processing of image data in an image processing apparatus is generally performed as follows using a page memory. Image data read by itself or image data input from an external device is temporarily stored in the buffer, and when several pages of image data are stored in the buffer, calculation is performed considering later reading. One page of image data stored in the buffer is developed at a predetermined address of the page memory thus read out, and the developed image data is read out and sent to the recording unit.
JP 2000-268169 A

  A conventional image processing apparatus that performs rotation processing of image data requires an arithmetic unit for calculating the address of a page memory to which image data is to be written by multiplication processing, etc., and avoids an increase in the configuration and cost. There is a problem that can not be. In addition, a buffer having a capacity corresponding to at least (the number of pixels in the row direction of the input image × the number of bits of the memory) must be provided. In this respect as well, the configuration is increased in bulk and cost. It has become.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an image processing method and an image processing apparatus that can perform rotation processing of image data even in a configuration that is smaller and lower in cost than conventional ones. .

  Another object of the present invention is to provide an image processing method and an image processing apparatus capable of rotating image data of a large size even when a buffer having a small capacity is used.

  An image processing method according to a first aspect of the present invention is the image processing method for rotating image data for one page expanded two-dimensionally in a memory, wherein the same number of image data for one page in the row direction and column direction. The transposition processing is executed by reading out the pixels as a unit, and the data after the transposition processing is written in the original address of the memory.

  In the image processing method of the first invention, the same number of pixels in the row direction and the column direction, that is, n × n (n: natural number), for one page of image data expanded two-dimensionally in the memory. An operation of reading a plurality of square pixels as a unit, performing a transposition process in which the row direction and the column direction are switched, and writing the data after the transposition process in the original address area of n × n of the memory Sequentially for data. Therefore, an arithmetic unit for calculating the write address in the page memory is unnecessary, and the size and cost of the configuration can be reduced. In addition, a large-capacity buffer is not necessary, and in this respect also, the configuration can be reduced in size and cost.

  According to a second aspect of the present invention, there is provided an image processing apparatus for rotating image data for one page, a page memory for expanding and storing the image data in two dimensions, and image data stored in the page memory. A buffer for accumulating partial image data having the same number of pixels in the row direction and column direction, and reading the partial image data to the buffer and writing the partial image data from the buffer to the page memory. The image processing apparatus includes means for executing transposition processing of image data, and means for reading out image data for one page after the transposition processing from the page memory.

  In the image processing apparatus of the second invention, one page of image data is expanded in the page memory, and the same number of pixels in the row direction and column direction, that is, n × n (n: natural number) ) By performing a transposition process in which the row direction and the column direction are interchanged by writing in the row direction from the page memory to the buffer and reading from the buffer to the page memory in the column direction. The operation of writing to the n × n original address area of the page memory is sequentially performed on the image data for one page, and the image data that has been transposed is rotated by controlling the read address and reading the image data. Output image data. Therefore, an arithmetic unit for calculating the write address in the page memory is not required, and it is only necessary to provide a buffer having a capacity of n × n pixels, and the configuration can be reduced in size and cost.

  An image processing apparatus according to a third invention is characterized in that, in the second invention, the rotation angle of the image data is 90 degrees or -90 degrees.

  In the image processing apparatus of the third invention, the rotation angle of the image data is 90 degrees or -90 degrees, and an image rotated 90 degrees clockwise or counterclockwise can be recorded on the paper.

  In the present invention, a circuit for performing complicated address calculation such as multiplication is unnecessary, and it is not necessary to provide a large-capacity buffer, and image data rotated by one side of the page memory is generated. Image data can be rotated by simply providing a buffer with a minimum size and a minimum capacity. As a result, it is possible to realize an image processing method and an image processing apparatus that can perform rotation processing of image data even when configured in a small scale.

  Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof. FIG. 1 is a block diagram showing a configuration of a facsimile composite apparatus 20 as an image processing apparatus of the present invention.

  The facsimile multifunction device 20 includes a control unit 1, a reading unit 2, a recording unit 3, a display unit 4, an operation unit 5, a ROM 6, a RAM 7, a codec unit 8, an image memory 9, a page memory 10, a buffer 11, a modem 12, an NCU ( Network Control Unit) 13, a PC interface unit 14 and the like. The facsimile multifunction device 20 reads a document by the reading unit 2 to obtain image data, read image data, image data received by facsimile communication, or image data corresponding to image data received from an externally connected PC. The recording section 3 has a recording function and a transmission function for facsimile transmission of the read image data or the received image data.

  Specifically, the control unit 1 is configured by a CPU, and is connected to the above-described hardware units of the facsimile multifunction device 20 via the bus 15. The control unit 1 controls them and is stored in the ROM 6. Various software functions are executed according to the control program. The reading unit 2 reads a document using a CCD image sensor, for example, and outputs the read image data. The optical unit irradiates and scans the original fed to the platen glass, and the reflected light from the original is taken into the CCD image sensor via a mirror, a lens, etc., and the scanned original image data is read. The read image data is output after being subjected to shading processing or the like.

  The recording unit 3 is an electrophotographic printer device, and is an image corresponding to image data of a document read by the reading unit 2, image data received by facsimile communication, image data sent from an external PC, and the like. On the paper. The display unit 4 is a display device such as a liquid crystal display device or a CRT display. The display unit 4 displays an operation state of the facsimile multifunction device 20, displays a screen for prompting an operation input to the user, and reads an image of a document read for transmission. Data, image data transmitted from other facsimile machines or PCs, etc. are displayed.

  The operation unit 5 includes character keys, numeric keys, abbreviated dial keys, one-touch dial keys, various function keys, and the like necessary for operating the facsimile composite apparatus 20. The operation unit 5 includes a rotation processing setting key 5a for setting whether or not to perform image data rotation processing using the page memory 10 and the buffer 11 as function keys. In addition, it is also possible to substitute a part or all of the various keys of the operation unit 5 by using the display unit 4 as a touch panel system. The ROM 6 stores in advance various software programs necessary for the operation of the facsimile composite apparatus 20. The RAM 7 is composed of SRAM, flash memory, or the like, and stores temporary data generated when software is executed. The codec unit 8 encodes and compresses image data and decodes the image data that has been encoded and compressed. The image memory 9 stores image data encoded by reading a document, image data received and encoded from another facsimile machine or PC, and the like.

  The page memory 10 is composed of, for example, an SDRAM (Synchronous Dynamic Random Access Memory), and image data for one page read by the reading unit 2 or one page received from another facsimile machine or PC. Accumulate image data. One page worth of image data accumulated and developed in the page memory 10 is read out by the recording unit 3, and an image corresponding to the image data is recorded. The buffer 11 has 64 flip-flops arranged in an 8 × 8 matrix, and each flip-flop holds binary data of each pixel. Data can be written / read between the page memory 10 and the buffer 11 in units of 8 × 8 64 pixel data of the page memory 10, and this data can be written as necessary. The generation of transposed image data in the rotation processing of the image data is performed by the / reading control.

  The modem 12 is connected to the bus 15 and is composed of a facsimile modem capable of facsimile communication. Similarly, the modem 12 is directly connected to the NCU 13 connected to the bus 15. The NCU 13 is hardware that performs operations of closing and opening the line L1 with a public switched telephone network (PSTN), and connects the modem 12 to the PSTN as necessary. The facsimile composite apparatus 20 is connected to other facsimile apparatuses by PSTN so that normal facsimile communication can be performed. The PC interface unit 14 is connected to an external PC via a communication line L2 such as a LAN, and exchanges data with the PC. Various image data created and edited by an external PC are transmitted to the facsimile multifunction apparatus 20 (PC interface unit 14) via the communication line L2, and an image corresponding to the transmitted image data is transmitted to the facsimile multifunction apparatus 20. The data is printed out on a sheet at (recording unit 3).

  The operation of the recording process in the facsimile multifunction machine 20 having such a configuration will be described below. FIG. 2 is a flowchart showing an operation procedure of the recording process, and FIGS. 3 to 5 are diagrams for explaining a 90-degree rotation process of image data in the clockwise direction.

  One page of image data read by the reading unit 2 or image data received from another facsimile machine or PC is stored in the page memory 10 (step S1). The controller 1 determines whether or not rotation processing is set based on whether or not the rotation processing setting key 5a is pressed (step S2). When the rotation process is not set (S2: NO), the image data is read from the page memory 10 to the recording unit 3 in the same order as the order written in the page memory 10 (step S8), and according to the read image data. The image is printed out on a sheet by the recording unit 3 (step S9).

  When rotation processing of image data is set (S2: YES), 64 pixels of 8 × 8 square shape in the image data stored in the page memory 10 are set as a unit (block), and one of them is selected. Block data is read from the page memory 10 and written to the buffer 11 (step S3). In this case, data is written in the row direction of the buffer 11. After this writing is completed, the data written in the buffer 11 is read from the column direction, and the read data is written in the original 8 × 8 memory area of the page memory 10 (step S4). In this way, transposed image data is generated as intermediate data for the rotation process. The control unit 1 determines whether transposed image data generation in units of 8 × 8 pixels is completed over one page stored in the page memory 10 (step S5). (S5: NO), the operation returns to S3 to generate transposed image data in the next block. When transposition image data generation is completed over one page (S5: YES), the operation proceeds to step S6.

  FIG. 3 shows an initial data accumulation state in the page memory 10, and image data for one page is divided into a total of six blocks of three in the row direction and two in the column direction. FIG. 4 shows transposed image data obtained by reading / writing data with the buffer 11.

  Next, the read address is controlled, the transposed image data is read from the page memory 10 to the recording unit 3 (S6), and the rotated image corresponding to the read transposed image data is printed out on the sheet by the recording unit 3 (step S7). ). In this case, the reading of each line from the page memory 10 is performed in the order described at the left end of FIG. 4, and one line is read alternately by two blocks. By such control of the read address, an image rotated 90 degrees clockwise as shown in FIG. 5 is obtained.

  By the way, in the present invention, transposed image data is generated in units of 8 × 8 pixels. Therefore, the transposed image data generation process is started after the end of the accumulation of one page of image data in the page memory 10. There is no need, and it is possible to start generating transposed image data every time data storage of 8 lines is completed. FIG. 6 is a flowchart showing the operation procedure of the rotational recording process in such a case, and FIG. In FIG. 7, hatched areas with a wide pitch represent image data before transposition, and hatched areas with a narrow pitch represent transposed image data.

  Accumulation of image data in the page memory 10 is started (step S11, FIG. 7A). The control unit 1 determines whether image data for 8 lines has been accumulated (step S12). When 8 lines are accumulated (S12: YES, FIG. 7B), the data of the block of 64 pixels of 8 × 8 square accumulated in the page memory 10 is read from the page memory 10. By writing in the row direction of the buffer 11 (step S13), then reading the data written in the buffer 11 from the column direction and writing it in the original 8 × 8 memory area of the page memory 10 (step S14), Transposed image data is generated (FIG. 7C). In this case, the image data accumulation process in the subsequent lines is performed in parallel with the transposed image data generation process.

  The control unit 1 determines whether or not the transposition image data generation is completed for one page (step S15). If the generation is not completed (S15: NO), the operation returns to S12 and the following 8 are similarly performed. Transposed image data in the line is generated (FIGS. 7D and 7E). When generation of the transposed image data is completed over one page (S15: YES, (FIGS. 7 (f) and (g)), the transposed image data is read by controlling the read address (step S16, FIG. 7 (h)). ) Print out an image rotated 90 degrees clockwise (step S17).

  In this way, the image data storage process in the page memory 10 and the transposed image data generation process can be performed in parallel, so that the delay time from the completion of the 1-page accumulation to the start of reading the transposed image data is reduced to 1 page. Can be reduced from the time required for generating the transposed image data for 8 minutes to the time required for generating the transposed image data for 8 lines, and the time required for the entire processing can be greatly shortened.

  Next, address control of the page memory 10 using SDRAM will be described. FIG. 8 is a timing chart showing data write / read operations in the SDRAM. Data writing and reading are continuously performed with 4 words (1 word is 8 bits) as a set while sequentially switching the four banks 0 to 4.

  First, a case where transposed image data is generated will be described. When generating transposed image data, data is written / read in the vertical direction (sub-scanning direction), not in the horizontal direction (main scanning direction). 9A, 9B, 10C, and 10D, when k is an integer, one line is 4k words, (4k + 1) words, (4k + 2) words, and (4k + 3) words. It is a figure which shows the address and bank in the case of comprising. When one line is composed of (4k + 1) words or (4k + 3) words, the access banks in the first column are 0, 1, 2, 3,... Or 0, 3, 2, 1,. A continuous access of words is possible. On the other hand, when one line is composed of 4k words or (4k + 2) words, the access banks in the first column are 0, 0, 0, 0,... Or 0, 2, 0, 2,. Thus, continuous access of 4 words cannot be performed.

  Therefore, when one line is composed of 4k words or (4k + 2) words, one address where no actual data exists is provided at the end of each line. That is, in order to make each line an odd word, dummy data of one word is added at the end. Addresses and banks in such a case are shown in FIGS. 11 (a) and 11 (b), respectively. As a result, the access banks in the first column circulate in the order of 0, 1, 2, 3,... Or 0, 3, 2, 1,.

  Next, a case where the generated transposed image data is read from the page memory 10 as rotated image data will be described. FIG. 12 is a diagram showing banks in each line of each block. Since transposed image data is generated in units of 8 × 8 pixels, in FIG. 12, 1 block 1 line 1 word, 2 blocks 1 line 1 word, 3 blocks 1 line 1 word,... 1 line 1 word of block, 2 lines 1 word of 1 block, 2 blocks 2 lines 1 word, ..., 2 lines 1 word of the last block, ..., 8 lines 1 word of 1 block, ... .., 8 lines 1 word of the last block, 1 line 2 words of 1 block,... At this time, the banks to be accessed are 0, 0, 0,..., 0 in one line and one word of each block, and 1, 1, 1,. Therefore, continuous access cannot be performed.

  Therefore, one address where no actual data exists is provided at the end of the eighth line (final line) in each block. That is, dummy data of one word is added at the end of the eighth line (final line). FIG. 13 shows addresses and banks in such a case. FIG. 13 shows an example in which one line is composed of 4k words, and a dummy address is provided at the end of the eighth line of each block. Since one line is composed of 4k words, a dummy address is provided at the end of each line as described above, and two dummy addresses are provided in the eighth line. Even when one line is composed of (4k + 1) words, (4k + 2) words, and (4k + 3) words, a dummy address is similarly added to the end of the eighth line of each block. .

  By providing dummy addresses in the 8th line (final line) in this way, as shown in FIG. 14, 1 block 1 line 1 word, 2 blocks 1 line 1 word, 3 blocks 1 line 1 word,. The access banks become 0, 1, 2,... In the order, and they circulate in different banks, thereby enabling continuous access of 4 words.

  In the image processing apparatus of the present invention described above, since SDRAM is used as the page memory, image data can be rotated with a simple configuration using an inexpensive memory.

  In the above-described embodiment, the 90-degree rotation process of the image data in the clockwise direction has been described as an example. However, the present invention can be similarly applied to the process of rotating the image data by 90 degrees in the counterclockwise direction. Of course.

  In the above-described embodiment, the transposed image data is generated in units of 8 × 8 pixels. However, this is an example, and square pixel blocks are used as units, for example, in units of 16 × 16 pixels. If so, the value of n may be arbitrary. A dummy address may be added at the end of the nth line of each block so that continuous bank access can be performed in the page memory 10 made of SDRAM.

  The use of SDRAM for the page memory is merely an example, and other types of memory may be used.

  Further, although the facsimile complex apparatus has been described as an example, it is needless to say that the present invention can be applied to all apparatuses such as a facsimile apparatus, a digital copying machine, and a printer that rotate and output acquired image data.

1 is a block diagram illustrating a configuration of an image processing apparatus (facsimile multifunction apparatus) according to the present invention. 6 is a flowchart illustrating an operation procedure of recording processing in the facsimile multifunction peripheral. It is a figure for demonstrating the 90 degree rotation process to the clockwise direction of image data. It is a figure for demonstrating the 90 degree rotation process to the clockwise direction of image data. It is a figure for demonstrating the 90 degree rotation process to the clockwise direction of image data. 6 is a flowchart showing an operation procedure of rotational recording processing in the facsimile multifunction machine. It is a figure which shows the data write state of a page memory. 6 is a timing chart showing data write / read operations in the SDRAM. It is a figure which shows an address and a bank in case one line is comprised with 4k word and (4k + 1) word. It is a figure which shows an address and a bank in case one line is comprised with (4k + 2) word and (4k + 3) word. It is a figure which shows the example of addition of the dummy address in each line in this invention. It is a figure which shows the bank in each line of each block. It is a figure which shows the example of addition of the dummy address in the last line in this invention. It is a figure which shows that a continuous bank access is possible.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2 Reading part 3 Recording part 5 Operation part 5a Rotation process setting key 6 ROM
7 RAM
10 page memory 11 buffer 20 facsimile compound device (image processing device)

Claims (3)

  In the image processing method of rotating image data for one page expanded two-dimensionally in a memory, transposition processing is performed on the image data for one page by reading out the same number of pixels in a row direction and a column direction as a unit. An image processing method which is executed and writes data after transposition processing to an original address of the memory.   In an image processing apparatus that rotates image data for one page, a page memory that develops and stores the image data two-dimensionally, and a row direction and a column direction in the image data stored in the page memory are the same. A buffer for accumulating partial image data of the number of pixels; and means for executing transposition processing of the partial image data by reading the partial image data into the buffer and writing the partial image data from the buffer to the page memory. An image processing apparatus comprising: means for reading out image data for one page after the transposition processing from the page memory. The image processing apparatus according to claim 2, wherein the rotation angle of the image data is 90 degrees or −90 degrees.

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