JPH11298723A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor capable of making copies of plural magnifications with respect to the setting at one time and making copies of the same size for originals of different sizes. SOLUTION: This image processor is provided with a line memory control part 41 and an arithmetic interpolation part 42. At the image reduction processing, an arithmetic interpolation processing is performed in the interpolation arithmetic part 42, and speed conversion is performed in line memories 51 and 52 by the line memory control part 41. At a magnification processing, the speed conversion is performed in the line memories 51 and 52 by the line memory control part 41, and the arithmetic interpolation processing is performed in the interpolation arithmetic part 42. Then, a magnification control data selection part 44 is provided with a function for simultaneously setting plural kinds of magnification control data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In a digital copying machine, a magnification conversion process of a digital image has conventionally been realized by controlling reading or writing of image data from or to a line memory using a 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 conversion, the level of the data level corrected by the three-dimensional 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 pixels that overlap the original pixel position,
leave it as it is. Moreover, the correction coefficient for each position is fixed.

[0003] Regarding the above concept, for example, Japanese Patent Laid-Open No.
Japanese Patent Application Publication No. 367080 discloses a technique in which an enlargement / reduction processing unit executes an enlargement / reduction processing when reading an image signal from a line memory after writing an input image signal in a line memory. Also, JP-A-8-1
No. 25836 describes that data interpolation is performed by a cubic function convolution in an interpolation operation circuit.

[0004]

In the scaling method in the conventional image processing apparatus, magnification conversion control data is
The corresponding magnification control data (magnification conversion control data) has been loaded into the memory based on the setting of the magnification specification by the CPU. The control data is sequentially read out at an address generated by an internal circuit. The control data loaded into the memory is usually one type of data. Therefore, there is a problem that a plurality of magnifications cannot be copied for one setting. Another problem is that it is not possible to make copies of the same size for documents of different sizes.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image processing apparatus capable of making copies of a plurality of magnifications for one setting and making copies of the same size for documents of different sizes. Aim.

[0006]

According to a first aspect of the present invention, there is provided an image processing apparatus comprising a line memory control unit and an interpolation operation unit. In the image processing apparatus, the speed is converted by the line memory by the line memory control unit, and the speed is converted by the line memory by the line memory control unit during the enlargement process, and the interpolation processing is performed by the interpolation calculation unit. A magnification control data selection unit having a function of selecting control data for interpolation calculation is provided.
It has a function of setting a plurality of types of magnification control data at one time.

[0007] To achieve the above object, the present invention provides a second aspect.
In the invention described in claim 1, in the invention described in claim 1, the magnification control data selection unit has a function of setting the magnification control data in a register system and a function of loading a plurality of magnification control data into a memory. It is characterized by the following.

[0008] In order to achieve the above object, a third aspect is provided.
According to the invention described in claim 1, in the invention described in claim 1, the magnification control data selection unit has a function of switching a plurality of magnification control data during copying.

According to another aspect of the present invention, the above object is achieved.
According to the invention described in claim 2, in the invention described in claim 2, the magnification control data selection unit sets magnification control data only for a specific magnification in a register system, and loads a plurality of other magnification control data into a memory. It is characterized by having.

[0010] In order to achieve the above object, the present invention is directed to claim 5.
According to the invention described in claim 1, in the invention described in claim 1, the magnification control data selection unit is configured to perform an operation designation by an external operation unit.
It has a function of obtaining copies of the same size for documents of different sizes.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an electrical system block diagram of the digital copying machine. The digital copying machine includes a document reading device 1, an IPU (image processing unit) 2, an image forming device (device main body of the digital copying machine) 3, an operation unit 4, a printer I / F processing unit 5, and an image memory. A section 6 is provided. Printer I / F
The processing unit 5 is connected to the external host 7.

The document reading apparatus 1 includes a document table, an exposure lamp,
Reading optical system 11 composed of mirror group and scanner control unit 12
It has. The IPU 2 includes a video processing unit 13 and a system control unit 14. The image forming apparatus 3 includes an image forming system 15 including a photosensitive member and electrophotographic processing means around the photosensitive member.
And a paper transport system 16 from the paper feed tray to the paper discharge tray, and a plotter control unit 17.

The operation unit 4 includes a CPU, a key switch,
It is composed of an LCD display unit and logic, communicates with the system control unit 14, detects a key input by an operator, and transmits its status information. Further, according to the received command information, various information such as the state of the machine is displayed on the LCD display unit.

The printer I / F processing unit 5 includes a CPU and logic, and performs a command I / F process between the system control unit 14 and the external host 7. External host 7
And video data transfer processing, and transfers video data sent from the external host 7 to the video processing unit 13. Thus, the digital copier can also function as a printer.

The image memory unit 6 comprises a CPU, logic, and an image memory, communicates with the system control unit 14, transmits status information for informing the state of the image memory unit 6, and receives commands. In accordance with the information, accumulation of received image data, various processing such as image synthesis, and transmission of processed data to the video processing unit 13 are performed.

The scanner controller 12 comprises a CPU and logic, communicates with a system controller 14,
The state is detected from each sensor of the document reading apparatus 1 and the status information is transmitted. Further, in accordance with the received command information, it controls the operation of each drive unit of the document reading device 1, performs a document scanning operation, and transfers an electric signal (video data) from the CCD to the video control unit 13 of the IPU 2.

The video processing unit 13 is composed of logic, and performs processing on video data transferred from the CCD based on parameter settings by the system control unit 14.
Image processing such as A / D conversion, shading correction, scaling processing, and dither processing is performed, and transmitted to the writing unit of the image forming apparatus 3 together with an image synchronization signal.

The system control unit 14 comprises a CPU and logic, and communicates with the scanner control unit 12, the plotter control unit 17, the operation unit 4, the printer I / F processing unit 5, the image memory unit 6, and the video processing unit 13. Then, it manages the status of each processing unit, sets parameters, executes processes, etc., and controls the entire digital copying machine.

The plotter controller 17 comprises a CPU and logic, communicates with the system controller 14,
The state of each sensor of the image forming apparatus 3 is detected, and the status information is transmitted. Further, based on the received command information and the video data from the video processing unit 13, the operation of the image forming system 15 and the sheet transport system 16 of the image forming apparatus 3 is controlled, and the image forming process on the sheet is performed.

FIG. 2 is a system block diagram of the video processing unit of the IPU shown in FIG. Video processing unit 1 of IPU2
3 is an A / D converter 32, a shading correction circuit 3
3, a filter processing circuit 35, a scaling processing circuit 36, a path control circuit (1) 37, an image processing circuit 38, a path control circuit (2) 39, and a print control circuit 40. The document reading device 1 includes a CCD image sensor 31 that scans a document according to a start signal, converts image information of the document into an electric signal through a filter 30G, and reads the signal. This C
The output of the CD image sensor 31 is output together with the synchronizing signal
It is transferred to the video processing unit 13 of U2.

The video processor 13 converts the electric signal (video data) sent from each CCD 31 into an A / D converter 3
Enter 2 The output side of the A / D converter 32 is connected to a shading correction circuit 33. And CC
The image information read by the D image sensor 31 is
The data is converted into digital image data by the D converter 32, and shading correction is performed. The image data after the shading correction is sent to the filter processing circuit 35 at the next stage.

The filter processing circuit 35 corrects the level of the target pixel with respect to the image data sent from the preceding shading correction circuit 33 based on the levels of the target pixel and peripheral pixels. The corrected image data is sent to the scaling processing circuit 36 at the next stage. The scaling processing circuit 36 will be described later in detail. The image data that has undergone the scaling process is output to the path control circuit (1) 37 at the next stage.

The path control circuit (1) 37 stores the image data sent from the scaling processing circuit 36 in the image memory section 6 in accordance with the parameters set by the system control section 14.
And to the image processing circuit 38. The image memory unit 6
Is transmitted to the image processing circuit 38. As described above, the path control circuit (1) 37 performs processing for switching the image data path. The image processing circuit 38
Γ correction processing for the image signal sent from the previous stage,
Image processing such as dither processing and error diffusion processing is performed, and transmitted to the next-stage path control circuit (2) 39 together with the synchronization signal.

The print control circuit 40 includes a ROM, in which a “multi secret pattern” and a “management number pattern” are stored.
The information of the ROM is transmitted to the path control circuit (2) 39 in accordance with the parameter setting by the system control unit 14.

The path control circuit (2) 39 is connected to the image processing circuit 38 and the image data sent from the printer control unit (externally via the printer I / F processing unit 5) in accordance with the parameters set by the system control unit 14. Image data transmitted from the host 7 is generated. Further, the image processing circuit 38 and the image data sent from the printer control unit, and the above-mentioned combined image data are selected. Further, the print image data sent from the print control circuit 40 is synthesized with the selected image data. Then, the processed image data is output together with the synchronization signal to the writing unit of the image forming apparatus 3 at the next stage.

FIG. 3 is an internal block diagram of the scaling processing circuit shown in FIG. The scaling processing circuit 36 includes a line memory control unit 41, an interpolation calculation unit 42, an image path control unit 43, and a scaling control data selection unit 44. Variable power control data selector 4
4 is a register 45, a memory control unit 46, a selector 47
Is provided. The line memories (1) 51 and (2) 52 are controlled by the line memory control unit 41. Further, a memory (RAM) 53 in which the scaling control data is stored is controlled by the memory controller 46 of the scaling control data selector 44. Of the input / output signals to each block, a thick line indicates image data, and a broken line indicates control data.

The magnification processing circuit 36 is a processing block for realizing a change in the magnification of image data in the main scanning (scanning for each line) of the copying machine. The scaling process is composed of two parts: an interpolation calculation process and a speed conversion process by the line memories 51 and 52. As for the flow of image data, interpolation conversion processing and speed conversion processing are performed at the time of equal magnification and reduction, and at the time of enlargement processing,
The speed conversion is performed and interpolation calculation processing is performed.

The speed conversion is realized by controlling the read enable or write enable signal for the run memories 51 and 52 by the line memory control unit 41. The interpolation operation interpolates the image data at the resampling position by the image data before and after in the main scanning direction using a three-dimensional convolution method.

In this embodiment, the range of the main scanning magnification change is 25.
% To 400% (0.5%). The choice of scaling is
This is controlled by a command, and the actual resampling position of the image data is stored in an internal memory (for example, 1024W × 4B).
It is given by the scaling control data written in the internal RAM (it) 53. As described above, two line memories are connected in parallel (51, 52), and the read enable signal and the write enable signal are controlled by the scaling control data to perform a toggle operation.

(1) Same-size processing In the case of the same-size processing, input image data passes through the interpolation calculator 42 under the control of the image path controller 43 and is written into the line memories 51 and 52. Line memories 51 and 52
After the image data written to is delayed by one line,
It is read out, synthesized under the active state of the read enable ren1, ren2, and output as an output image through the image path control unit 43. At this time, as shown in FIG. 4, ren and wen are always set to L, and the speed conversion is not performed, and the same magnification operation is performed.

(2) Reduction Processing In the case of the reduction processing, the input image data is sent to the interpolation calculation section 42 via the image path control section 43 and performs the interpolation calculation.
The sampling position for interpolation is determined by reading the scaling control data in the memory 53. The interpolated image data is written from the image path control unit 43 to the line memories 51 and 52. At this time, the data thinned out by the write enable control of the line memories 51 and 52 is output to the line memories 51 and 52.

The image data written in the line memories 51 and 52 is read out after being delayed by one line, synthesized under the active state of the read enable ren1 and ren2, and passed through the image path control unit 43. Output as an output image. Under the constant speed condition of ren = L at the time of reading,
The image data is directly taken in from the FIFOs 45 and 46. FIG. 5 shows an example of data control at the time of reduction.

(3) Enlargement processing In the case of enlargement processing, input image data is written to the line memories 51 and 52 through the image path control unit 43.
At the time of writing, at the constant speed condition of wen = L, the line memory 5
The input data is directly written into 1, 52. The image data written in the line memories 51 and 52 is read out after being delayed by one line, and read enable ren1,
Combined under the active state of ren2. At this time, the read is controlled by the read enable, and the speed conversion is performed.

The read data is transferred to the image path control unit 4.
Then, the signal is sent to the interpolation calculation unit 42 through the step 3 to perform the interpolation calculation. The sampling position for the interpolation is determined by reading the scaling control data in the memory 53. The enlargement process is performed by interpolating a plurality of times by changing the sampling position for the data for which reading has been stopped. The interpolated image data is output as output image data through the image path control unit 43. FIG. 6 shows an example of data control at the time of enlargement.

Next, the scaling control data selection section 44 will be described. The scaling control data selection unit 44 is a block diagram having a function of selecting line memory control data and control data for interpolation calculation. The magnification control data is set by the state setting of the register 45 according to the designated magnification. Alternatively, a plurality of scaling control data is loaded into the memory 53.

The number of scaling control data differs greatly depending on the magnification. For a particular magnification, for example, 2
In the case of 5%, 50%, 100%, 200%, and 400%, the number of control data is small, so that setting by the register 45 is sufficient. In such a case, the output of the state of the set register 45 is selected by the selector 47 according to the state of the magnification specifying command, and the line memory controller 41
To the interpolation calculation unit 42. For other magnifications,
Since the number of scaling control data is large, the data is loaded into each area of the memory 53, the output of the memory 53 is selected by the selector 47, and the output is provided to the line memory control unit 41 and the interpolation calculation unit 42.

An advantage of this method is that in the case of the above-described specific magnification, the magnification can be changed only by setting the register 45, and the use of the memory 53 is reduced.
In addition, since the variable magnification control data of the specific magnification and the other magnifications can be set at the same time, different magnification control data can be output by the selector 47 and the image data can be processed at different magnifications.

There are two possible applications of the present invention. As one of the applications, it is possible to process an image at two magnifications (limited to the specific magnification and other magnifications) in the same page. Since the scaling process according to the present invention is performed only in the line scanning direction, scaling in the scanner scanning direction is performed at a single magnification. Can be obtained. In particular, it is possible to specify a specific portion on the document using a marker or the like, and to enlarge or reduce only this specific portion. Therefore,
When editing is performed using a copying machine, it can be used as one editing means.

FIG. 7 is a diagram showing a first scaling example according to the present invention. The "A" part in the manuscript is the same size and "B"
It is an example showing a part enlarged. As part 2 of the application,
When making copies of the same size for a plurality of originals of different sizes, one copy can be made by designating the operation unit 4 (FIG. 1).
It is possible to obtain a plurality of types of copies with different magnification ratios by setting and operating each time.

FIG. 8 is a diagram showing a second scaling example according to the present invention. In this example, “A” of the first document is copied at the same magnification as it is, and “B” of the second document is reduced and copied.

The coefficients of the interpolation operation will be described. FIG. 9 is an explanatory diagram of a three-dimensional convolution method used at the time of interpolation calculation. FIG.
(B) shows the relationship between the pixel distance and the correction coefficient. FIG. 10 is a chart showing coefficients of the three-dimensional convolution method. In the column of code 0 in the table shown in FIG. 10, there are usually three types of coefficients, 50% and 25%. Among them, 50% and 25% are correction coefficients for eliminating white spots at the time of 50% and 25% reduction.

In the present embodiment, in the correction operation at the time of resampling in the scaling process, for the data at the same position as the original pixel position, three correction methods are selected for the data level after the data is corrected. it can. In a general case, the level of this data is the same as that of all the corrected data. In the case of specific magnifications (50% and 25%), coefficients as shown in FIG. 10 are used. If an image such as a one-dot line is corrected using this coefficient, it is possible to prevent the information of the image from being completely lost due to the position of the image.

[0043]

According to the first aspect of the present invention, since the function of selecting the line memory control data and the interpolation calculation control data is provided, it is possible to copy a plurality of magnifications for one setting. it can. Also, copies of the same size can be made for documents of different sizes.

According to the second aspect of the present invention, a function for setting magnification control data in a register system and a function for loading a plurality of magnification control data into a memory can be selected as necessary.

According to the third aspect of the present invention, since a function of switching a plurality of magnification control data during copying is provided, images of various forms can be obtained.

According to the fourth aspect of the invention, the magnification control data is set only for a specific magnification in a register system, and the other plurality of magnification control data are loaded into the memory. Effective utilization can be achieved.

According to the fifth aspect of the present invention, a function of obtaining a copy of the same size for a document having a different size by an operation designation of the external operation unit is provided, so that usability can be improved.

[Brief description of the drawings]

FIG. 1 is an electrical system block diagram of a digital copying machine.

FIG. 2 is a system block diagram of a video processing unit of the IPU shown in FIG.

FIG. 3 is an internal block diagram of the scaling processing circuit shown in FIG. 2;

FIG. 4 is a diagram showing signal levels in data control at the same magnification.

FIG. 5 is a diagram showing signal levels in data control at the time of reduction.

FIG. 6 is a diagram showing signal levels in data control at the time of enlargement.

FIG. 7 is a diagram illustrating a first scaling example according to the present invention;

FIG. 8 is a diagram illustrating a second scaling example according to the present invention.

FIG. 9 is an explanatory diagram of a three-dimensional convolution method.

FIG. 10 is a table showing coefficients of a three-dimensional convolution method.

[Explanation of symbols]

 36 Magnification processing circuit 41 Line memory control unit 42 Interpolation operation unit 43 Image path control unit 44 Magnification control data selection unit 45 Register 46 Memory control unit 47 Selector 51, 52 Line memory 53 Memory

Claims (5)

[Claims] 1. A line memory control unit and an interpolation operation unit, wherein during a reduction process, an interpolation operation process is performed by an interpolation operation unit, a speed conversion is performed by a line memory by a line memory control unit, and a line memory is executed during an expansion process. An image processing apparatus that performs speed conversion by a line memory by a control unit and performs interpolation calculation processing by an interpolation calculation unit, comprising a magnification control data selection unit having a function of selecting data for line memory control and control data for interpolation calculation. An image processing apparatus, wherein the magnification control data selection unit has a function of setting a plurality of types of magnification control data at one time. 2. The magnification control data selection unit according to claim 1, wherein the magnification control data selection unit has a function of setting magnification control data in a register system and a function of loading a plurality of magnification control data into a memory. Characteristic image processing device. 3. The image processing apparatus according to claim 1, wherein the magnification control data selection unit has a function of switching a plurality of magnification control data during copying. 4. The magnification control data selection unit according to claim 2, wherein the magnification control data selection unit has a function of setting magnification control data only for a specific magnification in a register system, and loading a plurality of other magnification control data into a memory. An image processing apparatus comprising: 5. The apparatus according to claim 1, wherein the magnification control data selection unit has a function of obtaining a copy of the same size for a document having a different size according to an operation designation of an external operation unit. Image processing device.