JPS61105966A - Change of magnification processing system of picture - Google Patents

Abstract

PURPOSE:To make change of magnification of a picture in the longitudinal and transverse directions at high speed and at optional magnification without requiring complicated circuits and software by combining the length and breadth conversion of a picture and change of magnification of a picture by line operation. CONSTITUTION:A line operation variable magnification processor 12 is started by a controlling signal C, and an original picture designated by a command is read from a memory 13 successively and magnification is changed by line operation according to a designated rate of change of magnification F. The result is written on the memory 13. When this is completed, a host CPU 10 gives a command for 90 deg. rotation to a length and breadth conversion processor 11 by a controlling signal C. Then, the line operation variable magnification processor 12 is started again, and change of magnification is made by thinning out of lines or superposition of lines, and the result is written on the memory 13.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an image scaling processing method for vertically and horizontally enlarging or reducing (scaling) a digital image in a digital image processing device such as a digital copying machine or a digital facsimile. .

[Prior art]

In conventional digital image processing devices, image scaling is performed vertically and horizontally by performing line operations such as thinning out lines or overlapping consecutive lines, while horizontally scaling the image by shifting bits or This is done by bit operations such as AND or OR. Vertical scaling using line operations can be performed relatively easily, and a simple circuit or software can suffice; however, bit manipulation for horizontal scaling takes time. In addition, complex address management must be performed in parallel, which requires complex circuits and software. For these reasons, digital image processing devices that perform vertical and horizontal magnification at arbitrary magnifications have become quite expensive and require a considerable amount of processing time.

〔the purpose〕

An object of the present invention is to provide an image scaling processing method that can quickly scale an image vertically and horizontally at any scaling factor without requiring complicated circuits or software.

〔composition〕

As described above, changing the magnification of an image by line operation can be performed relatively easily and at high speed. Further, devices having an image scaling function are often provided with means for vertically and horizontally converting five images, and such vertical and horizontal conversion of images can be performed at a considerably high speed.

In view of these circumstances, the present invention executes vertical/horizontal scaling of an image by combining vertical/horizontal conversion of one image and scaling of the image by line operation. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a flowchart showing a general procedure for image scaling processing in an embodiment of the present invention, and also illustrates changes in the image at each processing stage. FIG. 2 is a schematic block diagram of the system 11 for executing this image scaling process.

In FIG. 2, 10 is a host CPU.

Aspect/horizontal conversion processor 11. Line operation magnification processor 1
2 and memory 13 via a system bus 14. The memory 13 stores image data to be processed, processing intermediate data, and processing result data.

The vertical/horizontal conversion processor 11 performs vertical/horizontal conversion (90° or 270° rotation processing) of the lowermost image under the control of the host CPtJlO.

Under the control of the host CPU 10, the line operation scaling processor 12 thins out lines in the case of reduction, and generates overlapping lines in the case of enlargement. Image scaling processing by such line operations and image vertical/horizontal conversion processing by the vertical/horizontal conversion processor 11 may be the same as conventional ones.
Therefore, the details of each will not be explained.

Next, with reference to FIG. 1, vertical and horizontal scaling processing for five images will be explained in order. First, host cput.

The area of the original image to be scaled vertically and horizontally is designated (step 1). This designation is carried out from the host CPU 10 via the system bus 14 to the vertical/horizontal conversion processor 11. Segment values and offset values (SA) for line operation scaling processor 12.

Image width (X) and height (Y), maximum width of one line (XM)
This is done by sending parameters such as , variable magnification (F), etc. as commands. Next, the host CPU10 activates the line operation scaling processor 12 using the control signal (C). The line operation variable power processor 12 is
The original image specified by the command is stored in memory 13.
The image is read sequentially from 1 to 3, and the magnification is changed by line operation according to the specified magnification ratio (F) (the magnification is changed in the direction perpendicular to the line, in this case, the vertical direction of the original image is changed), and the results are stored in the memory 13. (Step 2). If the scaling is reduction, lines are thinned out according to the scaling ratio. Conversely, in the case of enlargement, overlapping lines are generated according to the magnification ratio.

When the line operation scaling processor 12 completes one process, it sends a completion signal (RFT) to the host CPU10 via the system bus 14. Upon receiving this end signal, the host CPU10 instructs the vertical/horizontal conversion processor 11 to perform a 90° rotation operation using a control signal (C). The vertical/horizontal conversion processor 11 sequentially reads the vertically scaled image data written in the memory 13, rotates it by 90 degrees, and writes the result back to the memory 13 (step 3).
When this 90° rotation processing is completed, the vertical/horizontal conversion processor 11 sends a termination signal (RET).

Upon receiving this termination signal, the host cpuio restarts the line operation variable magnification processor 12 using a control signal (C). The line operation scaling processor 12 stores the image data rotated by 90 degrees after the previous scaling in the memory 13.
Load sequentially from

Scaling is performed by thinning out lines or overlapping lines (scaling in the direction perpendicular to the lines, which here corresponds to lateral scaling of the original image), and the results are written in the memory 13 (step 4). When this process is completed, a termination signal (RET) is sent from the line operation scaling processor 12.

Upon receiving this end signal, the host CPU 10 instructs the vertical/horizontal conversion processor 11 to perform a 2-degree 0° (or -90@) rotation process. The vertical/horizontal conversion processor 11 sequentially reads the processed image data stored in the memory 13,
Perform a rotation of 270° (or -90°) and write the result to the memory 13 (step 5), thus transforming the original image vertically and horizontally, as schematically shown on the left side of Figure 1. A magnified image (the case of enlargement is shown in FIG. 1) is obtained in the memory 13. In addition.

At each step of the procedure two images are shown, which are not shown in the figure.
displayed on the screen.

In the above description, after scaling one image in the vertical direction, the image is rotated by 90 degrees, then the image is scaled in the vertical direction, and then rotated by 270 degrees.

Moreover, the order of the combination of magnification and rotation may be changed as necessary. For example, it is also possible to first rotate the image by 90 degrees and perform scaling once, then rotate it by 270 degrees or 190 degrees and perform scaling to obtain the final scaled image. Further, the aspect conversion processor 11 and the line operation scaling processor 12 may each be physically independent devices, or may be configured as software executed in a common software.

〔effect〕

As explained above, according to the present invention, the vertical and horizontal scaling of an image is performed by combining scaling and vertical/horizontal conversion using line operations without using bit operations that take processing time or require complicated hardware or software. Therefore, image scaling can be performed at high speed with simple hardware or software.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing the procedure of image scaling processing according to an embodiment of the present invention, and FIG. 2 is a schematic block diagram of an image scaling processing system according to the same embodiment. 10... Host CPU, 11... Aspect/horizontal conversion processor, 12... Line operation scaling processor,
13...Memory, 14...System bus.

Claims (1)

[Claims] (1) It has an aspect conversion means for rotating an image by 90° or 270°, and a scaling means for changing the size (enlarging or reducing) the image by line operation, and the rotation operation and scaling of the image by each of the above means An image scaling processing method characterized by scaling an image vertically and horizontally by a combination of operations.