JP2005176125A - 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 even when the image data adopt a binary form or a multi-value form. <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 when the number of bit is 1 bit and 4×4 pixels when the number of bit is 2 bits), in response to the number of bits of the pixel configuring the image data from the page memory 10 to a buffer 11 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 address areas of the page memory 10. The image processor can output rotated image data by reading the transposed image data by controlling their reading addresses. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image processing method and an image processing apparatus for transposing 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.

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. Further, in the image processing apparatus disclosed in Patent Document 1, regardless of whether the image data is in a binary format or a multi-value format, a conventional binary data rotation circuit is used to rotate the multi-value data. Processing can be performed.
JP-A-11-213147

  However, the above-described image processing apparatus has a memory that secures an area for storing data before rotation processing and an area for storing data after rotation processing in which the row direction and column direction of data are switched, that is, data after rotation processing. However, there is a problem that an increase in structure and cost are unavoidable.

  The present invention has been made in view of such circumstances, and image processing that can perform transposition processing of image data with a smaller and lower-cost configuration than conventional ones, regardless of whether the image data is in binary format or multi-value format. It is an object to provide a method and an image processing apparatus.

  An image processing method according to a first aspect of the present invention is an image processing method in which image data for one page expanded two-dimensionally in a memory is transposed, in a row direction and a column according to the number of bits constituting each pixel of the image data. Image data is read in units of pixels having the same direction, transposition processing is executed on the read image data, and the data after transposition processing is written to the original address of the memory.

  In the image processing method according to the first aspect of the present invention, it is determined according to the number of bits (the number of gradations) constituting each pixel of image data for one page of image data expanded two-dimensionally in a memory. The row direction and the column direction are the same number of pixels, that is, a plurality of square pixels of n × n (n: natural number) are read as a unit, and the transposition process is performed by switching the row direction and the column direction, and the data after the transposition process is obtained. The operation of writing to the n × n original address area of the memory is sequentially performed on the image data for one page. Therefore, it is not necessary to store the data before the transposition process and the data after the transposition process separately in the memory regardless of whether the image data is in the binary format or the multi-value format. Cost can be reduced.

  An image processing apparatus according to a second aspect of the invention is an image processing apparatus for transposing 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 the column direction according to the number of bits constituting each pixel, and reading the partial image data into the buffer and reading the partial image data from the buffer to the page A transposition processing means for performing transposition processing of the partial image data by writing to a memory is provided.

  In the image processing apparatus according to the second aspect of the present invention, image data for one page is expanded in the page memory, and according to the number of bits (the number of gradations) constituting each pixel of the image data for the image data. Writing in the row direction from the page memory to the buffer in the row direction and reading from the buffer to the page memory in the column direction in units of a plurality of pixels having the same number of rows and columns determined, that is, n × n (n: natural number) square pixels Then, a transposition process in which the row direction and the column direction are exchanged is performed, and the operation of writing the data after the transposition process in the n × n original address area of the page memory is sequentially performed on the image data for one page. Therefore, regardless of whether the image data is in binary format or multi-value format, it is not necessary to store the data before transposition processing and the data after transposition processing separately in the memory, and n × n pixels. It is only necessary to provide a buffer having a capacity, 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 page memory is an SDRAM.

  In the image processing apparatus of the third invention, an SDRAM (Synchronous Dynamic Random Access Memory) is used as a page memory. Therefore, transposition processing of image data can be performed with a simple configuration using an inexpensive memory.

  In the present invention, a circuit for performing a complicated address calculation such as multiplication is unnecessary, and the data before transposition processing and the data after transposition processing are stored in the memory regardless of whether the image data is in binary format or multi-value format. Since it is not necessary to store data separately and image data that has been transposed on one side of the page memory is generated, a circuit with a small circuit size and a buffer with the minimum necessary capacity can be provided. The image data can be transposed. As a result, it is possible to realize an image processing apparatus that can perform transposition processing of image data even if it is configured on 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 multifunction device 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 the image data, and decodes the encoded and compressed image data. The image memory 9 stores image data encoded by reading a document, image data received from another facsimile apparatus or PC, and encoded.

  The page memory 10 is composed of SDRAM, and stores one page of image data read by the reading unit 2 and one page of image data received from another facsimile machine or PC. 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. When the bus line is 8 bits (line), the buffer 11 has 64 flip-flops configured in an 8 × 8 matrix, and each flip-flop holds data of each pixel.

  Between the page memory 10 and the buffer 11, it is possible to write / read the data in the page memory 10 according to the number of bits constituting each pixel of the image data, and write this data as necessary. The generation of transposed image data in the rotation processing of the image data is performed by the / reading control. For example, when the format of the image data is 1 bit (binary) per pixel, data can be written / read out in units of 8 × 8 64 pixel data of the page memory 10. Thus, when the format of the image data is 2 bits (4 values) per pixel, data can be written / read in units of 4 × 4 16 pixel data of the page memory 10. It is like that. That is, the buffer 11 adjusts the number of pixels for writing / reading data to / from the page memory 10 in accordance with the number of bits constituting each pixel of the image data, so that the format of the image data is binary or quaternary. Even in the format, data can be written / read.

  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 the operation procedure of this recording process, and FIGS. 3 to 7 are diagrams for explaining a 90-degree rotation process of image data in the clockwise direction. Hereinafter, in order to simplify the description, it is assumed that the format of the image data is either binary or quaternary, but each of the image data constituting the image data has an 8-value or 16-value format. The number of bits of the pixel may be arbitrary.

  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 written in the page memory 10 (step S12), and the image data corresponding to the read image data. The image is printed out on a sheet by the recording unit 3 (step S13).

  If image data rotation processing has been set (S2: YES), it is determined whether the image data stored in the page memory 10 is in binary format (step S3). When it is determined in S3 that the image data is in the binary format (S3: YES), 64 pixels of 8 × 8 square shape in the image data stored in the page memory 10 are used as a unit (block ), The data of the one block is read from the page memory 10 and written to the buffer 11 (step S4). 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 S5). In this way, transposed image data is generated as intermediate data for the rotation process.

  The control unit 1 determines whether or not generation of transposed image data in units of 8 × 8 pixels is completed over one page stored in the page memory 10 when the image data is in a binary format (Step S1). S6) If not completed (S6: NO), the operation returns to S4 to generate transposed image data in the next block.

  On the other hand, if it is determined in S3 that the image data is not in binary format, that is, if it is determined that the image data is in quaternary format (S3: NO), the image data stored in the page memory 10 Using 16 pixels of 4 × 4 square as a unit (block), the data of one block is read from the page memory 10 and written to the buffer 11 (step S7). 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 4 × 4 memory area of the page memory 10 (step S8). In this way, transposed image data is generated as intermediate data for the rotation process.

  The control unit 1 determines whether or not generation of transposed image data in units of 4 × 4 pixels is completed over one page stored in the page memory 10 when the image data is in a four-value format (Step S1). S9) If not completed (S9: NO), the operation returns to S7 to generate transposed image data in the next block.

  When the generation of the transposed image data is completed for one page (S6: YES, S9: YES), the read address is controlled to read the transposed image data from the page memory 10 to the recording unit 3 (step S10). A rotated image corresponding to the read transposed image data is printed out on a sheet by the recording unit 3 (step S11).

  FIG. 3 shows the initial data storage state in the page memory 10 when the image data is in a binary format. The image data for one page includes a total of 6 image data in three rows and two columns. Divided into blocks. FIG. 4 shows transposed image data obtained by reading / writing data with the buffer 11. When the image data is in binary format, each line is read from the page memory 10 in the order described at the left end of FIG. 4, and is read out line by line alternately in two blocks.

  FIG. 5 shows the initial data accumulation state in the page memory 10 when the image data is in a quaternary format. The image data for one page includes a total of 6 image data of 3 in the row direction and 2 in the column direction. Divided into blocks. FIG. 6 shows transposed image data obtained by reading / writing data with the buffer 11. When the image data is in a quaternary format, each line is read from the page memory 10 in the order described at the left end of FIG. 6, and is read out one line at a time in two blocks. Regardless of whether the image data is in binary format or image data is in quaternary format, an image rotated 90 degrees clockwise as shown in FIG. 7 can be obtained by controlling the readout address as described above.

  Next, address control of the page memory 10 using SDRAM will be described. Since SDRAM is internally pipelined, it can perform high-speed processing. FIG. 8 is a timing chart showing data write / read operations in the SDRAM. The SDRAM is composed of four banks (Banks 0, 1, 2, and 3). The control unit 1 synchronizes with the rising edge of the clock signal (CLK signal), the row address strobe signal (/ RAS signal), the column By outputting an address strobe signal (/ CAS signal) and a write enable signal (/ WE signal) to the page memory (SDRAM) 10, the data at the memory address specified by the row number and column number of the SDRAM memory space is output. Controls write / read operations. A signal having “/” added to the head of the signal name means that it is low active (significant when it is low level).

When the control unit 1 outputs / RAS signal = L (low level), / CAS signal = H (high level), and / WE signal = H to the SDRAM, the SDRAM determines that the bank is active. , One of the banks 0, 1, 2, and 3 in the SDRAM and the row address (Addr0 _R , 1 _R , 2 _R , 3 _R ) in the bank are determined.

When the control unit 1 outputs the / RAS signal = H, the / CAS signal = L, and the / WE signal = L to the SDRAM, the SDRAM determines that the write / auto precharge is performed, and Any one of banks 0, 1, 2, and 3 and the column address (Addr0 _C , 1 _C , 2 _C , 3 _C ) in the bank are determined, and the column address in the bank and the above-described bank active Data (D ₀ , D ₁ , D ₂ , D ₃ ) is written to the row address in the bank determined by.

On the other hand, when the control unit 1 outputs the / RAS signal = H, the / CAS signal = L, and the / WE signal = H to the SDRAM, the SDRAM determines that the read / auto precharge is performed, and Any one of banks 0, 1, 2, and 3 and the column address (Addr0 _C , 1 _C , 2 _C , 3 _C ) in the bank are determined, and the column address in the bank and the above-described bank active Data (D ₀ , D ₁ , D ₂ , D ₃ ) stored in the row address in the bank determined by the above is read. Note that SDRAM generally has CAS latency that causes a delay in the execution of operations. FIG. 8 shows a case where the CAS latency is “2”, that is, Data (D ₀ , D ₁ , D ₂ , D ₃ ) is read at a time delayed by 2 clocks.

  In this manner, 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. When / RAS signal = H, / CAS signal = H, and / WE signal = H are output to the SDRAM, the SDRAM does not perform any operation (no operation NOP (No OPeration)).

  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) instead of 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, that is, odd words, the access banks in the first column are 0, 1, 2, 3,. ..., and continuous access of 4 words is possible. On the other hand, when one line is composed of 4k words or (4k + 2) words, that is, even words, the access bank in the first column is 0, 0, 0, 0,. , 2,..., 4 words cannot be accessed continuously.

  Therefore, when one line is composed of even-numbered words (4k words, (4k + 2) words), one address at which 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. First, a case where image data is in a binary format will be described. FIG. 12 is a diagram showing banks in each line of each block when the image data is in binary format. 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, 1 block 2 lines 1 word, 2 blocks 2 lines 1 word, ..., last block 2 lines 1 word, ..., 1 block 8 lines 1 word, ..., last block 8 lines 1 word , 1 line 2 words in one block,..., 8 lines last word in the last block are accessed in this order. 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 on the 8th line (final line) in this way, as shown in FIG. 14, 1 line 1 word of 1 block, 1 line 1 word of 2 blocks, 1 line 1 word of 3 blocks,. The access banks become 0, 1, 2,... In order, and they circulate in different banks, thereby enabling continuous access of 4 words.

  Next, a case where the image data is in a quaternary format will be described. FIG. 15 is a diagram showing a bank in each line of each block when the image data is in a quaternary format. Since transposed image data is generated in units of 4 × 4 pixels, in FIG. 15, 1 block 1 line 1 word, 2 blocks 1 line 1 word, 3 blocks 1 line 1 word,. 1 line 1 word, 1 block 2 lines 1 word, 2 blocks 2 lines 1 word, ..., last block 2 lines 1 word, ..., 1 block 4 lines 1 word, ..., last block 4 lines 1 word , 1 line 2 words in one block,..., 4 lines last word in the last block are accessed in this order. 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 fourth line (final line) in each block. That is, dummy data of one word is added at the end of the fourth line (final line). FIG. 16 shows addresses and banks in such a case. FIG. 16 shows an example in which one line is composed of 4k words, and a dummy address is provided at the end of the fourth 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 fourth line. Even when one line is composed of (4k + 1) words, (4k + 2) words, and (4k + 3) words, although not shown, similarly, one dummy address is added to the end of the fourth line of each block. .

  By providing dummy addresses on the 4th line (final line) in this way, as shown in FIG. 17, 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 order, and they circulate in different banks, thereby enabling continuous access of 4 words.

  In the above-described embodiment, the bus line has 8 lines and the buffer 11 has 64 flip-flops configured in an 8 × 8 matrix, but this is an example. For example, when there are 16 bus lines, a buffer having 256 flip-flops arranged in a 16 × 16 matrix may be used, and if a square pixel block is used as a unit, The value of n may be arbitrary. A dummy address may be added to the end of the last line of each block so that continuous bank access can be performed in the page memory 10 made of SDRAM.

  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. 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 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 in case image data is a binary format. 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. It is a figure which shows the bank in each line of each block in case image data is a 4 value format. 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

Claims (3)

  In an image processing method for transposing image data for one page expanded two-dimensionally in a memory, image data in units of pixels having the same number of rows and columns in accordance with the number of bits constituting each pixel of the image data , Executing transposition processing on the read image data, and writing the data after transposition processing to the original address of the memory.   In an image processing apparatus that transposes image data for one page, according to a page memory that expands and stores the image data in two dimensions, and the number of bits that constitute each pixel of the image data stored in the page memory A buffer for storing the partial image data having the same number of pixels in the row direction and the column direction, and 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 characterized by comprising transposition processing means for executing transposition processing.   The image processing apparatus according to claim 2, wherein the page memory is an SDRAM.

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