JP2001034746A - Image input system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image input system capable of yielding highly accurate image data, saving memory and reducing data transfer time. SOLUTION: This image input system inputs image data of a diagram described on a paper sheet and read by an image input device 17. The system is provided with a buffer memory 14 for temporarily storing the image data inputted from the device 17, an affine transformation circuit 13 performing affine transformation processing of the image data of the memory 14, a compression circuit 12 performing compression processing of the image data after the affine transformation and an image bus 5 transmitting compressed data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to hand-drawn drawings and CAs.
The present invention relates to an image input system capable of reading a D output drawing.

[0002]

2. Description of the Related Art A conventional image input system of this type will be described with reference to FIG. That is, the main memory 42
It stores programs for system control and saves input image data. The system bus 43 transfers control data, image data, and the like. The image input device 45 includes a handwritten drawing or a CA as a drawing drawn on a sheet.
The output drawing of the D system is read, and the image data is input. The image input device I / F circuit 44 controls the image input device 45. Image processing circuit 46
Performs image processing such as compression, decompression, and affine transformation on image data stored in the main memory. here, The affine transformation is a process of enlarging, reducing, and rotating image data. The video I / F circuit 47 displays image data and the like on a display 48. The CPU 41 controls the whole of the various circuits.

Under such a configuration, image data input from the image input device 45 is transmitted to the main memory 4 through the image input device I / F circuit 44 and the system bus 43.
2 is stored. When performing image processing on the input image data, the CPU 41 reads out the image data from the main memory 42 and sends it to the image processing circuit 46 to perform the image processing. The image-processed data is read by the CPU 41 from the image processing circuit 46 and stored in the main memory 42.

Further, image data is displayed on a display 48.
, The data must be read from the main memory 42 and sent to the video I / F circuit 47.

If the data on the main memory is compressed data, it is necessary to perform decompression processing by the above-mentioned image processing circuit and restore the original image data. Further, since the image data is usually larger in size than the display area of the display 48, it is necessary to perform a reduction process once to display the entire image on the screen of the display 48.

[0006]

As described above, in the conventional image input system, image data transfer, image processing, and display display processing are performed centering on the main memory 42. Are frequently performed, it takes time, and the load on the CPU 41 also increases.

In addition, image data input from the image input device 45 often causes expansion errors specific to the input device in both the main scanning direction and the sub-scanning direction. For this reason, CA
When a drawing used in the D system, a handwritten drawing, or the like is read by the image input device 45 and input as image data, this expansion / contraction error becomes a problem, and drawings and the like that do not match dimensions are mixed. This is a problem.

It is an object of the present invention to provide an image input system capable of obtaining highly accurate image data, saving memory and reducing data transfer time.

[0009]

According to the present invention, there is provided an image input system having means for inputting image data relating to a drawing drawn on a sheet read by an image input device. A buffer memory for temporarily storing image data input from the image input device, an affine transformation circuit for performing affine transformation processing on the image data in the buffer memory, and a compression circuit for performing compression processing on the affine transformed image data. , An image bus for transmitting compressed data.

In such a configuration, image data input from an image input device is an image input I / F.
It is temporarily stored in the buffer memory through the circuit. Next, the image data in the buffer memory is subjected to desired enlargement, reduction, and rotation processing by the affine transformation circuit. continue,
The affine-transformed image data is converted into compressed data by a compression circuit and sent to an image bus through a bus I / F circuit.

Thus, according to the present invention, highly accurate image data can be input by correcting expansion / contraction errors of an image input device by enlargement / reduction processing of an affine transformation circuit. Further, since the transfer of the image data is performed in a compressed format, the transfer time can be reduced.

[0012]

An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram of an image input system according to an embodiment of the present invention.
The same parts as in FIG. 5 which is a conventional example are denoted by the same reference numerals, and description thereof will be omitted.

The MPU 1 controls the entire apparatus. The main memory 2 stores programs for controlling the entire apparatus, parameter data, and the like. The system bus 3 is a transmission path for control information data, image data, and the like. The bus bridge circuit 4 connects the system bus 3 and the image bus 5. The image bus 5 is a transmission path for image data.

Next, the configuration of the image input unit 100 will be described. That is, the image input device 17 scans a drawing or the like and inputs image data. The image input device I / F circuit 15 inputs image data from the image input device 17. The buffer memory 14 is a memory for temporarily storing input image data. The affine transformation circuit 13 includes a buffer memory 14
Affine transformation (enlargement, reduction, rotation) of image data
To process. The compression circuit 12 compresses the affine-transformed image data. The bus I / F circuit 11 outputs the compressed data to the image bus 5. Input control circuit 16
Controls each circuit of the image input unit 100.

Next, the configuration of the image processing section 200 will be described. That is, the compressed data memory 22 stores the data compressed by the image input unit 100. The compressed data memory control circuit 21 controls access to the compressed data memory 22. The bus I / F circuit 23 takes in the compressed data from the image bus 5. The expansion circuit 24 expands the compressed data stored in the compressed data memory 22 and restores the original image data. The affine transformation circuit 26 performs affine transformation processing on the image data expanded by the expansion circuit 24. The image memory 28 stores image data. The image memory control circuit 27 controls access to the image memory 28. The compression circuit 25 compresses the image data from the affine transformation circuit 26. The image processing control circuit 30 controls each circuit of the image processing unit 200 as a whole.

Next, the configuration of the image data display unit 300 will be described. That is, the image memory access circuit 31 reads a desired rectangular area of the image memory 28. The two-dimensional address generation circuit 32 stores the image memory 2
Eight addresses of the desired rectangular area are generated. The video signal conversion circuit converts the read image data into a video signal. The video display control circuit 35 controls each circuit of the image data display unit 300.

Next, the operation of the image input system configured as described above will be described with reference to FIG. First, the operation of the image input unit 100 will be described. That is, the image input device 17 is controlled by the MPU through the input control circuit 16 and the image input device I / F circuit 15.
1 does. Image data input from the image input device 17 is temporarily stored in the buffer memory 14 through the image input device I / F circuit 15. Buffer memory 1
The image data stored in the affine transformation circuit 1
In step 3, enlargement, reduction, and rotation are performed.

Here, the affine transformation circuit 13 mainly performs enlargement and reduction processing at a previously calculated correction rate in order to correct the expansion / contraction error of the input image data. Note that the expansion / contraction error is an error caused by the accuracy of the image input device 17 and means that the length of the input line segment differs from the actual length of the line segment.

As shown in FIGS. 3A and 3B and FIG. 4, the correction rates in the main scanning and sub scanning directions are calculated in advance in the following procedure. First, as step S1, a test chart is input. In the test chart, a line segment having a determined length for calculating the correction rates in the main scanning direction and the sub scanning direction is drawn.

Next, in step S2, the line segment of the input image data in the main scanning and sub-scanning directions is tracked by the MPU 1 to calculate the length (number of dots).

Next, in step S3, a correction factor is calculated based on the length (dot number) of the tracked line segment and the expected value (dot number). The expected value (the number of dots) is the length of a line segment on the test chart, and is determined by the input resolution of the image input device 17.

The specific calculation of the correction rate is performed as follows.

First, the number of dots per 1 mm is calculated from the input resolution of the image input device.

If the resolution is 400 bpi, a 1 mm line segment is 15.748 dots.

The number of dots of 1 mm = 400 (bpi) /25.4 (mm / inch) = 15.748 (dot / mm) Next, an expected value is calculated.

An expected value is calculated from the length of the line segment of the test chart and the input resolution.

Expected value Dx = Tx (mm) × 1 in main scanning direction
5.748 (dot / mm) Expected value Dy = Ty (mm) × 15.748 in the sub-scanning direction
(Dot / mm) Calculation of the correction rate is as follows.

Correction rate Kx in the main scanning direction = (expected value in the main scanning direction) / input number of dots in the main scanning direction = Tx (mm) × 15.748 (dot / mm) / Dx (dot) Sub-scanning Direction correction rate Ky = (expected value in sub-scanning direction) / input number of dots in sub-scanning direction = Ty (mm) × 15.748 (dot / mm) / Dy (dot) In the main scanning and sub-scanning directions The correction calculation is as follows.

Based on the number of dots in the main scanning direction and the sub-scanning direction and the respective correction rates, correction calculation of input image data is performed.

Correction value in the main scanning direction = total do in the main scanning direction
t number × correction rate K in main scanning direction × correction value in sub-scanning direction = total number of dots in sub-scanning direction × correction rate Ky in sub-scanning direction Note that the above calculation of the correction rate should be performed at the initial time or periodically. This can be easily performed by using the present system and the drawings to be input.

Next, in step S4, the calculated correction rate is stored in a nonvolatile memory by the MPU 1.

After the correction rates in the main scanning and sub-scanning directions are determined, the image data is corrected by the affine transformation circuit every time an image is input, and the expansion / contraction error is cut.

Of course, the enlargement / reduction processing may be used for normal enlargement / reduction of image data as well as correction of expansion / contraction error. When the image data input horizontally is rotated in the vertical direction, a rotation process is performed.

The compressed data compressed by the compression circuit 12 is
The data is output to the image bus 5 through the bus I / F circuit 11. The compressed data on the image bus 5 is stored in the main memory 2 through the bus bridge circuit 4 and the system bus 3. When the compressed data is transferred to the image processing unit 200, the compressed data is stored in the compressed data memory 22 from the bus I / F circuit 11 through the image bus 5 and the bus I / F circuit 23. The compressed data memory 22 is controlled by the compressed data memory control circuit 21.

Next, the operation of the image processing section 200 will be described.

As described above, the compressed data stored in the compressed data memory 22 by the image input unit 100 is stored in the decompression circuit 2.
4, the image data is restored to the original image data, and the data is enlarged, reduced, and rotated by the affine transformation circuit 26 as necessary, and stored in a desired rectangular area of the image memory 28. The access control of the image memory 28 is performed by the image memory control circuit 27.

The image data on the image memory 28 can be converted to compressed data through the affine conversion circuit 26 and the compression circuit 25 and stored in the compressed data memory 22. The bus I / F circuit 29 is an I / F circuit that connects the image memory 28 and the image bus 5,
It is used when inputting / outputting image data on the image memory 28.

Here, the image processing control circuit 30 controls the entire image processing described above.

The MPU 1 has a compressed data memory 22
The above compressed data and the image data on the image memory 28 can be accessed through the compressed data memory control circuit 21 and the image memory control circuit 27, respectively.

Next, the operation of the image data display unit 300 for displaying the image data on the image memory 28 on the display 34 will be described.

First, the image data on the image memory 28 is read out by the image cutout circuit 31 into a rectangular area having a size suitable for the display area. At this time, the address of the rectangular area is generated by the two-dimensional address generation circuit 32.

The image data extracted by the image extraction circuit 31 is converted into a video signal by a video signal conversion circuit 33 and displayed on a display 34.

Here, the video display control circuit 35 controls each circuit for video display.

As described above, according to this embodiment, image data having an expansion / contraction error input from an image input device can be converted into highly accurate data by correcting the image data with an affine conversion circuit in accordance with the expansion / contraction ratio. Further, by compressing the image data by the compression circuit, the data size can be reduced, so that the memory can be saved and the data transfer time can be reduced.

Further, when a large amount of image data needs to be input, data can be input from a plurality of image input devices, so that the input time can be reduced.

Further, the compressed data from the image input unit is restored to the original image data by decompression processing, and the affine transformation processing is performed to expand and reduce the image data.
Deformation processing of the reduced / rotated image can be performed.
On the other hand, the image data on the image memory can be converted into compressed data again through an affine transformation circuit and a compression circuit.

Further, since the input image data is displayed on the display in a short time, the data can be easily confirmed.

The present invention is not limited to the above embodiment, but can be implemented in the following manner. As shown in FIG. 5, a large amount of image data can be stored by connecting a magnetic disk unit including a magnetic disk device 36 and a magnetic disk device I / F circuit 37 to the configuration shown in FIG.

In the above embodiment, the SCSI,
By adding an external communication circuit of a general-purpose interface such as a LAN, connection with another system becomes possible.

Further, in the above embodiment, by adding a pointing device such as a mouse and scrolling the image memory, image data larger than the display screen can be displayed.

[0052]

As described above, according to the present invention, image data having an expansion / contraction error input from an image input device can be converted into highly accurate data by correcting the image data with an affine conversion circuit according to the expansion / contraction ratio. Further, the present invention can provide an image input system capable of reducing the data size by compressing image data by a compression circuit, saving memory and reducing data transfer time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an image input system according to the present invention.

FIG. 2 is a diagram showing a data flow in FIG. 1;

FIG. 3 is a view for explaining a method of calculating a correction rate of input image data.

FIG. 4 is a flowchart of calculating a correction rate of input image data.

FIG. 5 is a block diagram of an image input system according to another embodiment.

FIG. 6 is a block diagram of an image input system according to the related art.

[Explanation of symbols]

1 MPU, 2 main memory, 3 system bus, 4 bus bridge circuit, 5 image bus, 11 bus I / F
Circuit, 12 compression circuit, 13 affine transformation circuit, 14
... Buffer memory, 15 ... Image input device I / F circuit, 16 ... Input control circuit, 17 ... Image input device, 2
DESCRIPTION OF SYMBOLS 1 ... Compressed data memory control circuit, 22 ... Compressed data memory, 23, 29 ... Bus I / F circuit, 24 ... Decompression circuit, 2
5 compression circuit, 26 affine conversion circuit, 27 image memory control circuit, 28 image memory, 30 image processing control circuit, 31 image memory access circuit, 32 two-dimensional address generation circuit, 33 video signal conversion Circuit, 34 display, 35 video display control circuit, 36 magnetic disk drive, 37 magnetic disk drive I / F circuit, 100 image input unit, 200 image processing unit, 300 image data display unit.

Claims (4)

[Claims] 1. An image input system having means for inputting image data relating to a drawing drawn on a sheet read by an image input device, wherein said means temporarily stores image data input from said image input device. A buffer memory that performs affine transformation processing on the image data of the buffer memory, a compression circuit that performs compression processing on the affine-transformed image data, and an image bus that transmits the compressed data. Image input system. 2. A compressed data memory for storing the compressed data, a compressed data control circuit for generating an address at the time of accessing the compressed data memory, and connecting the compressed data to the image bus. The image input system according to claim 1, further comprising a bus I / F circuit. 3. A decompression circuit for decompressing compressed data,
An affine transformation circuit that performs affine transformation processing on the decompressed data, an image memory that stores the affine-transformed image data, an image memory control circuit that generates an address of the image memory, 3. The image input system according to claim 2, further comprising a compression circuit for compressing the image data. 4. An image memory access circuit for reading a desired rectangular area from the image memory, an image memory control circuit for generating a two-dimensional address of the rectangular area, and a video signal for converting the read image data into a video signal The image input system according to claim 3, further comprising a conversion circuit.