JP2000196868A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor which can set plural spaces for a memory, where magnification control data are stored. SOLUTION: An inputted digital image signal is subjected to speed conversion by line memories 2365 and 2366, and magnification converting control data is stored beforehand in a memory 2367, and this data is read out in accordance with magnification designation, and data to be resampled is corrected to convert the magnification. In this image processor, plural memory spaces of the memory 2367 where magnification conversion control data is stored at set. In this case, memory spaces are divided into two areas which are a fixed area and a variable area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus used in a copying machine and a facsimile machine having a scaling function.

[0002]

2. Description of the Related Art In a so-called digital image forming apparatus having a function of forming an image based on a digital signal, for example, a digital copying machine, magnification conversion processing of a digital image has been performed using a line memory. Specifically, the magnification conversion processing is performed by controlling the reading (reading) or writing (writing) of image data from / to the line memory. In the case of the reduction processing including the same magnification, the image data is reduced and written into the line memory. In the case of enlargement processing, enlargement processing is performed after image data is read from the line memory. As the level of the image data after the magnification change, data corrected by the cubic function convolution method with respect to the resampling position determined by the magnification is used. The resampling position is equally divided into a plurality of pixels depending on the accuracy, and is set to the closest position based on the magnification. Correction processing is not performed on a pixel overlapping the original pixel position, and the pixel is left as it is. Moreover, the correction coefficient for each position is fixed.

[0003] As a technique related thereto, for example, those disclosed in Japanese Patent Application Laid-Open Nos. 4-366080 and 8-125258 are known.

[0004]

As described above, in the conventional scaling process, the magnification conversion control data is loaded into the memory based on the setting of the magnification specified by the CPU, and the internal circuit is controlled. Are sequentially read out based on the address generated in step (1). The data to be loaded into the memory is usually one type of data. Therefore, it was not possible to cope with operations such as making copies at a plurality of magnifications for one setting or making copies of the same size for documents of different sizes.

SUMMARY OF THE INVENTION The present invention has been made in view of such a point, and an object of the present invention is to provide an image processing apparatus which can copy a plurality of magnifications for one setting. Another object of the present invention is to provide an image processing apparatus capable of making copies of the same size for documents of different sizes.

[0006]

In order to achieve the above object, a first means converts the speed of an input digital image signal in a line memory, stores magnification conversion control data in the memory, In the image processing apparatus for reading out the data in accordance with the designation of the data and correcting the data to be resampled and converting the magnification, a plurality of memory spaces of a memory for storing the magnification conversion control data are set.

The second means is characterized in that the memory space in the first means is divided into two areas, a fixed area and a variable area.

[0008] The third means is characterized in that the memory space in the first or second means is independently accessed.

According to a fourth aspect, in the image processing apparatus based on the same premise as the first means, a plurality of memories for storing the magnification conversion control data are mounted.

A fifth means is the fourth means, wherein the magnification control data stored in each of the memories is independent of each other.

A sixth means is the fourth or fifth means, further comprising a control means for reading out magnification control data from each of the memories and outputting a plurality of images at different magnifications from the same document. .

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a digital copying machine according to an embodiment of the present invention. The digital copying machine includes an original reading device 100 and an image processing circuit (IP
U-image processing unit) 200;
The IPU 200 mainly includes an image forming apparatus 300.
Includes a printer I / F processing unit 210, an image memory unit 22
0 and an operation unit 250 are connected, and an external host 260 is connected to the printer I / F processing unit 210.

The original reading apparatus 100 includes an exposure lamp 1
01, first to third mirrors 102, 103, 104,
An image reading unit 110 including the CCD 105 and a scanner control unit 120 are included. The scanner control unit 120 includes a CPU and logic,
The document reading apparatus 100 communicates with the system control unit 201 at 00 to detect the state from each sensor of the document reading apparatus 100 and transmits status information of each sensor. Further, based on the received command information and the video data from the video processing unit 202, the operation of each image forming process unit and the paper transport unit of the image forming apparatus 300 is controlled, and the image forming process on the transfer paper is executed.

The operation unit 250 includes a CPU, key switches, L
A system control unit 2 comprising a CD display unit and logic
01, and detects key input by the operator,
Send the status information. Further, according to the received command information, various information such as the state of the machine is displayed on the LDC display unit.

The printer I / F processing unit 210 includes a CPU and logic, and performs command I / F processing between the system control unit 201 and the external host 260. In addition, it performs a process of transferring video data to and from the external host 260, and transfers video data sent from the external host 260 to the video processing unit 202. Thus, the digital copying machine according to this embodiment can also function as a printer.

The image memory unit 220 includes a CPU, a logic, and an image memory, communicates with the system control unit 201, transmits status information for notifying the state of the image memory unit 220, and receives commands. According to the information, various processing such as accumulation of received image data and image synthesis, and processing of transmitting the processed data to the video processing unit 202 are performed.

The IPU 200 includes the video processing unit 202 and the system control unit 201 as described above. The video processing unit 220 is constituted by logic, and the scanner control unit 12
0, plotter control unit 301, operation unit 230, printer I
It communicates with the / F processing unit 210, the image memory unit 220, and the video processing unit 202, and manages the status of each processing unit, sets parameters, executes processes, and manages the entire digital copying machine.

The image forming apparatus 300 includes a plotter control unit 3
01, a writing unit 302, and an image forming unit 303. The image forming unit 303 includes a photosensitive drum 310, an image forming element provided along the outer peripheral surface of the photosensitive drum 310, and a sheet transport system for transferring an image formed by the image forming element to a sheet. Become. The image forming elements include a charging charger 311, a developing device 312, a transfer charger 313,
The cleaning device 314 includes other known devices such as a static elimination lamp and an eraser.
20, a paper feed roller 321, a registration roller 322, a fixing device 323, a paper discharge roller 324, and a paper discharge tray 325.

The system configuration of the video processing unit 202 of the IPU 200 is shown in the block diagram of FIG. Video processing unit 20
2 is an A / D conversion circuit 232, a shading correction circuit 233, a filter correction circuit 234, a scaling processing circuit 23
5, the first bus control circuit 236, the image processing circuit 238,
A second bus control circuit 239 and a print control circuit 240 are provided. Image data read by the CCD 105 of the document reading device 100 is input to the video processing unit 202. That is, the document reading apparatus 100
Scans the original 150 by the start signal and
A CDD image sensor 105 is provided which converts the 50 pieces of image information into electric signals through a filter 130G and reads the electric signals. The output of the CCD image sensor 105 is transferred to the video processing unit 202 of the IPU 200 together with a synchronization signal.

In the video processing unit 202, an electric signal (video data) sent from the CCD 105 corresponding to each of the RGB colors is input to an A / D conversion circuit 232, and the A / D converted image data is converted into a shading correction circuit 233. Output to The image information read by the CCD image sensor 105 and subjected to A / D conversion is subjected to shading correction by a shading correction circuit. The image data after the shading correction is supplied to a filter correction circuit 235 at the next stage.
Sent to

The filter correction circuit 235 corrects the level of the pixel of interest with respect to the image data sent from the shading correction circuit 233 at the preceding stage, based on the levels of the pixel of interest and peripheral pixels. The corrected image data is sent to the next-stage scaling processing circuit 236. The image data subjected to the scaling process is output to the first path control circuit 237 at the next stage.

The first path control circuit 237 transmits (1) the image data sent from the scaling unit 236 to the image memory unit 220 and the image processing circuit 238 according to the parameters set by the system control unit 201. .

(2) The image data sent from the image memory unit 220 is sent to the image processing circuit 238.

For this purpose, an image data path switching process is performed.

The image processing circuit 238 performs image processing such as γ correction processing, dither processing and error diffusion processing on the image signal sent from the preceding stage, and together with the synchronization signal, the second path control circuit 239 of the next stage. Send to

And the like.

The print control circuit 240 has a ROM in which a “multi secret pattern” and a “management number pattern” are stored.
And the like, are coded and stored. According to the parameter setting by the system control unit, (1) the image processing circuit 238 and the printer I / F processing unit 21
Then, image data is generated by combining the image data sent from 0.

(2) Image processing circuit 238 and printer I / O
The selection processing of the image data sent from the F processing unit 210 and the composite image data is performed.

(3) The print image data sent from the print control circuit 240 is combined with the selected image data.

The processed image data is stored in the writing unit 30 of the image forming apparatus 300 at the next stage.
2 is output together with the synchronization signal.

FIG. 3 is a block diagram showing a detailed configuration of the scaling processing circuit 236 in FIG. 2, wherein a solid line indicates image data and a dotted line indicates control data. The scaling processing circuit 236
This processing block realizes a change in the magnification of image data in the main scanning of the copying machine, and includes a line memory control unit 2361, an interpolation calculation unit 2362, an image path control unit 2363, and a variable magnification memory control unit 2364. The scaling process is composed of two parts: an interpolation calculation process and a speed conversion process by the line memories 2365 and 2366.

The flow of the image data is as follows: "at the time of equal magnification and reduction, interpolation processing is performed and speed conversion processing is executed"; and at enlargement processing, speed conversion is performed and interpolation calculation processing is performed. I have. Speed conversion is performed by line memories 2365 and 2366
, By controlling a read enable (ren) or write enable (wen) signal. In FIG. 3, this function is realized by the line memory control unit 2361. The interpolation calculation unit 2362 interpolates the image data at the resampling position by the image data before and after in the main scanning direction using the cubic function convolution method.

In this embodiment, the range of the main scanning magnification change is from 25% to 400% (0.5%). The selection of enlargement / reduction is controlled by a command, and the actual resampling position of the image data is given by the scaling control data written in the internal memory 2367. In this embodiment,
Two line memories 2365 and 2366 are provided in parallel, and the read enable signal and the write enable signal are controlled by the scaling control data to perform a toggle operation.

In the equal magnification process, input image data is written by the image path control unit 2363 to the line memories 2365 and 2366 via the interpolation calculation unit 2362. The image data written in the line memories 2365 and 2366 is 1
Read after line delay, read enable re
The images are synthesized under the active states of n1 and ren2, and output as an output image through the image path control unit 2363. At this time, as shown in the timing chart of the data control at the same magnification in FIG. 4, the read enable (ren),
The write enable (wen) is always set to L, and performs the same-size operation without changing the speed.

In the reduction process, the input data is sent to the interpolation calculation unit 2362 through the image path control unit 2363, and the interpolation calculation unit 2362 performs the interpolation calculation. The sampling position for the interpolation is determined by reading the scaling control data in the RAM (memory) 2367. The interpolated image data is sent from the image path control unit 2363 to the line memories 2365, 2365.
366. In this case, the line memory 236
The data decimated by the write enable control of the write enable circuits 2365 and 2366 is output to the line memories 2365 and 2366.

The image data written in the line memories 2365 and 2366 are read out after being delayed by one line,
Synthesized under the active state of read enable,
The image is output as an output image through the image path control unit 2363. At the time of reading, as shown in the timing chart of the data control at the time of reduction in FIG. 5, the image data is directly taken in from the line memories 2365 and 2366 under the constant speed condition of ren = L.

In the enlargement processing, the input image data passes through the image path control unit 2363 and is stored in the line memories 2365 and 236.
6 is written. At the time of writing, the input data to the line memories 2365 and 2366 is written as it is under the constant speed condition of wen = L. The image data written in the line memories 2365 and 2366 are read out after being delayed by one line, and are synthesized under the read enable state. At this time, the speed conversion is performed by controlling the reading from the read enable.

The read data is stored in the image path control unit 2.
The signal is sent to the interpolation calculation unit 2362 through the 363 to perform the interpolation calculation. The sampling position for the interpolation is determined by reading the scaling control data in the RAM (memory) 2367. The enlargement process is performed by interpolating a plurality of times by changing the sampling position for the data whose reading has been stopped. The interpolated image data is stored in the image path controller 23.
It is output as output image data through 63. FIG. 6 is a timing chart showing the timing of data control at the time of enlargement.

The scaling memory control unit 2364 is a block having a function of selecting control data used in the line memory control unit 2361 and the interpolation calculation unit 2362. A plurality of scaling control data are loaded into the RAM (memory) 2367 according to the designated magnification. The number of variable power control data differs greatly depending on the magnification. For example, 25%, 50%, 100%, 200%, 400
In the case of%, it is sufficient to repeat the same data and the number of control data can be reduced. In such a case, the five magnification control data are always stored in the fixed area 710 of the memory as shown in the memory map of FIG. To a fixed address. In the case of other magnifications, since the number of magnification control data is large, the data is loaded into the variable area 720 of the memory. Data necessary for the line memory control unit 2361 and the interpolation calculation unit 2362 are selected from the respective address areas 710 and 720 based on the designated magnification and provided.

The feature of this method is that a plurality of specific magnification data can be simultaneously set with a small increase in memory, so that different magnification processing can be performed on image data to which different magnification control data has been output.

When such processing becomes possible, for example,
It is possible to process the image at two magnifications (limited to the specific magnification and other magnifications) in the same page. Since the scaling process in this embodiment is performed only in the line scanning direction, scaling in the scanning direction of the scanner is performed at a single magnification. The effect of can be obtained. In particular, it is possible to specify a specific portion on the document by means such as a marker, and to enlarge or reduce only this specific portion. Such a function can be used as one editing means when editing is performed using a copying machine. FIG. 8A shows an example using such a function. This example
The “A” image portion on the upstream side in the scanner scanning direction is the same size, and the “B” image portion on the downstream side is enlarged.

When a copy of the same size is made for a plurality of originals having different sizes, a plurality of copies having different magnifications can be obtained by one setting and operation by designating the external operation unit. It is possible. FIGS. 8B and 8C show examples of using this function. FIG. 8B shows an example of enlargement, and FIG. 8C shows an example of reduction.

Next, the interpolation calculation in the interpolation calculation unit 2362 will be described. FIGS. 9A and 9B are explanatory diagrams showing a cubic function convolution method used at the time of the interpolation calculation. FIG. 9A shows the calculation of the gradation at the virtual sampling point, and FIG. 9B shows the relationship between the distance between pixels and the correction count. The coefficients used in the cubic function convolution method in FIG. 9 are as shown in Table 1 below.

[0045]

[Table 1]

In the table of code 0 in the table, "normal", "50"
There are three types of coefficients, "%" and "25%", of which "50%" and "25%" are correction coefficients for eliminating white spots at the time of 50% and 25% reduction.

In this embodiment, the data level after correction of the data at the same position as the original pixel position for the correction operation at the time of resampling in the scaling process is 3
You can select any of the correction methods. In a general case, the level of this data is the same as the data before correction. For example, in the case of a characteristic magnification such as 50% and 25%, coefficients as shown in Table 1 are used. If an image such as a one-dot line is corrected with this coefficient, it is possible to prevent the image information from being completely lost due to this image position.

Since the correction method itself using the cubic function convolution method is known, a detailed description is omitted here.

FIG. 10 is a block diagram showing another embodiment of the scaling unit 236. This embodiment is an example in which a plurality of memories are mounted instead of setting a plurality of memory spaces of a RAM (memory) 2367 in FIG.
First to third three RAMs (memory) 2367-
1, 2,367-2, 2367-3 (FIG. 11). All other components are configured the same as those shown in FIG. Each memory 2367-1,
2367-2 and 2367-3 store scaling control data, respectively. The scaling memory control unit 2364 stores the data necessary for the line memory control unit 2361 and the interpolation calculation unit 2362 in the memory based on the specified magnification. 2367-
1,2,367-2,2367-3 and read
provide.

The advantage of this configuration is that, when a plurality of copies are required for copying the same document, a plurality of magnifications are required, the designation is made from the external operation unit 250 as shown in FIG. One setting and one operation
That is, it is possible to obtain a plurality of copies 1201, 1202, and 1203 having different magnifications from one original 1200.

In addition, since each part and the function and operation of each part, which are not particularly described, are configured in the same manner as in the above-described embodiment, duplicate description will be omitted.

[0052]

As described above, according to the first aspect of the present invention, since a plurality of memory spaces of the memory for storing the magnification conversion control data are set, a plurality of magnification data can be prepared at the same time. Copies of a plurality of magnifications can be made for one setting, and copies of the same size can be made for documents of different sizes.

According to the second aspect of the present invention, since the memory space is divided into the fixed area and the variable area, a plurality of data can be stored with a small amount of memory.

According to the third aspect of the present invention, since the memory spaces are independently accessed, a plurality of magnification control data can be read freely.

According to the fourth aspect of the present invention, since a plurality of memories for storing magnification conversion control data are mounted, a plurality of magnification control data can be mounted, and data can be read from each memory. This allows you to make multiple magnification copies for one setting,
Also, copies of the same size can be made for documents of different sizes.

According to the fifth aspect of the present invention, since the magnification control data stored in each memory is independent, each data can be read and processed independently of other data.

According to the sixth aspect of the present invention, since the control means for reading out the magnification control data from each memory and outputting a plurality of images of a plurality of variable magnifications from the same original is provided, it is possible to copy a plurality of magnifications from the same original. Can be obtained by one setting and operation.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a digital copying machine including an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a detailed configuration of an image processing unit in FIG. 1;

FIG. 3 is a block diagram illustrating a detailed configuration of a scaling unit in FIG. 2;

FIG. 4 is a timing chart showing the timing of data control at the same magnification.

FIG. 5 is a timing chart showing the timing of data control at the time of reduction.

FIG. 6 is a timing chart showing timing of data control at the time of enlargement.

FIG. 7 is an explanatory diagram showing a memory space of a memory in FIG. 3;

FIG. 8 is an explanatory diagram illustrating an image processing result when a document of different sizes is scaled by a plurality of magnifications.

FIG. 9 is an explanatory diagram showing a method of correcting a cubic function convolution.

FIG. 10 is a block diagram showing a detailed configuration of another embodiment of the scaling unit in FIG. 2;

FIG. 11 is an explanatory diagram showing an example of a memory in FIG. 10;

FIG. 12 is an explanatory diagram showing an image processing result when a plurality of memories are mounted and originals having different sizes are scaled by a plurality of magnifications.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 Document reading device 200 Image processing device (IPU) 236 Magnification processing circuit 238 Image processing circuit 2361 Line memory control unit 2362 Interpolation calculation unit 2363 Image path control unit 2364 Magnification memory control unit 2365, 2366 Line memory 2366, 2366-1 , 2366-2, 2366-3
Memory (RAM)

Claims (6)

[Claims] 1. An input digital image signal is speed-converted by a line memory, magnification conversion control data is stored in the memory, and the data is read out in accordance with designation of a magnification.
An image processing apparatus for converting a magnification by correcting data to be resampled, wherein a plurality of memory spaces of a memory for storing the magnification conversion control data are set. 2. The image processing apparatus according to claim 1, wherein the memory space is divided into two areas, a fixed area and a variable area. 3. The image processing apparatus according to claim 1, wherein the memory spaces are independently accessed. 4. An input digital image signal is speed-converted by a line memory, magnification conversion control data is stored in the memory, and the data is read out according to the designation of the magnification.
An image processing apparatus for correcting a data to be resampled and converting a magnification, wherein a plurality of memories for storing the magnification conversion control data are mounted. 5. The image processing apparatus according to claim 4, wherein magnification control data stored in each of said memories is independent. 6. The image processing apparatus according to claim 4, further comprising control means for reading magnification control data from each of the memories and outputting a plurality of images of a plurality of magnifications from the same document.