JPH04290067A - Dither image data working system - Google Patents

Abstract

PURPOSE:To realize the magnification/reduction processing of original image data with fidelity by making the density of an image into a numeric value, applying magnification or reduction working to it, and after that, returning it to a dither pattern again. CONSTITUTION:Information is read in from a dither pattern information storage part 2 on which the original image data is recorded by a dither density conversion part 1 via a storage buffer 4, and data obtained by making into the numeric value is outputted to a gradation information storage part 3. A dither image can be obtained by reading the data again at the conversion part 1 after applying the magnification or reduction processing, and converting gradation to the dither image. Thereby, it is possible to perform the magnification or reduction processing with fidelity to an original image.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing image data in an information processing apparatus, and more particularly to a method for processing digital dithered image data in a personal computer.

0002

[Prior Art] Conventionally, when performing image processing on a personal computer, an image reader or a handy scanner is used to read images such as photographs, and intermediate density is expressed by a dither pattern, which is then converted into binary information. and is imported into a personal computer. For this reason,
When enlarging or reducing image data in a personal computer, image data is inserted or deleted at appropriate intervals in appropriate parts of a dithered image. for example,
As shown in FIG. 3, enlarged data 22 is created by performing simple enlargement processing on the original image data 11.

0003

[Problems to be Solved by the Invention] In the conventional image processing magnification/reduction method as described above, a linear image is Since data is inserted or data is thinned out in a line at an appropriate position in the middle of the dither pattern depending on the reduction magnification, the image data deteriorates significantly.

0004

[Means for Solving the Problems] The dithered image data processing method of the present invention first converts the density of a dithered image into numerical information, then processes the numerical information by enlarging or reducing it. By returning the information to a dither pattern, it is possible to realize faithful enlargement or reduction processing for the original image data.

That is, the dithered image data processing method of the present invention obtains grayscale image data by converting dithered original image data into grayscale image data, and performs processing by performing enlargement processing or reduction processing on the grayscale image data. After obtaining post-gradation image data, a conversion process is performed to convert the gradation into dither image data on the post-processing gradation image data to obtain dither image data after enlargement or reduction.In particular, dither pattern an information storage section, a gradation information storage section, and when converting a dither pattern into gradation information, reads information from the dither pattern information storage section and outputs it to the gradation information storage section to convert the gradation information into a dither pattern. In this case, a dither/gradation image data converting section is used, which reads information from the gradation information storage section and writes the information into the dither pattern information storage section.

[0006]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a flowchart showing one embodiment of the present invention.

In this embodiment, as shown in FIG. 1, gradation image data 13 is obtained by converting dithered original image data (original image data) 11 into gradation image data (dither→gradation image data conversion 12). Furthermore, enlargement processing or reduction processing (enlargement/reduction processing 14) is performed on this. Processed grayscale image data 1 obtained by enlargement processing or reduction processing
5 is further subjected to a conversion process (shade→dither image data conversion 16) for converting shading into dithered image data to obtain dithered image data 17 after enlargement/reduction.

FIG. 2 is a block diagram showing the dither→gradation image data conversion 12 and the gradient→dither image data conversion 16 in the embodiment of FIG.

In FIG. 2, for example, when converting a dither pattern into gradation information, a dither/gradation image data conversion section 1 reads information from a dither pattern information storage section 2 and outputs it to a gradation information storage section 3. On the other hand, when converting the gradation information into a dither pattern, the information is read from the gradation information storage section 3 and written into the dither pattern information storage section 2. The dither-gradation image data converting unit 1 includes a dither pattern data storage buffer 4 used for exchanging data with the dither pattern information storage unit 2, and a portion to be processed from the dither pattern data storage buffer 4 and temporarily a dither processing target storage unit 5 for storing the dither processing target storage unit 5; a converter 6 that converts the information stored in the dither processing target storage unit 5 into gray scale information; and a gray scale information target storage unit that temporarily stores the gray scale information output from the converter 6. 7, a gradation information storage buffer 8 that buffers the information stored in the gradation information object storage 7, and a gradation data-dither pattern conversion table (conversion table) 9 that the converter 6 refers to when converting into gradation information. It is made up of.

By performing conversion using such a dither/gradation image data converter 1, it is possible to obtain enlarged data 17 in which the original image data 11 has been faithfully enlarged, as shown in FIG. .

0012

[Effects of the Invention] As explained above, the image data processing method of the present invention first converts the density of a dithered image into numerical information, and then processes the numerical information to enlarge or reduce it. By returning the information to the dither pattern again, there is an effect that it is possible to realize an enlargement process or a reduction process that is faithful to the original image data.

[Brief explanation of the drawing]

FIG. 1 is a flow chart showing one embodiment of the present invention.

FIG. 2 is a block diagram illustrating dither → grayscale image data conversion and grayscale → dither image data conversion in the embodiment of FIG. 1;

FIG. 3 is a plane showing a comparison of enlarged data of original image data according to a conventional method and enlarged data according to the method of the present invention.

[Explanation of symbols]

1 Dither-gradation image data converter 2 Dither pattern information storage unit 3 gradation information storage unit 4 Dither pattern data storage buffer 5
Dither processing target storage unit 6 Converter 7 Grayscale information target storage unit 8 Grayscale information storage buffer 9 Grayscale data-dither pattern conversion table (
Conversion table) 11 Dither original image data (original image data) 12
Dither → shading image data conversion 13 shading image data 14 Enlargement/reduction processing 15 Processed shading image data 16 shading → dither image data conversion 17
Dithered image data 18 Enlarged data 22 Enlarged data

Claims (2)

[Claims] 1. Obtaining grayscale image data by converting dithered original image data into grayscale image data; obtaining processed grayscale image data by performing enlargement processing or reduction processing on the grayscale image data; A dithered image data processing method characterized in that dithered image data is obtained after being enlarged or reduced by performing a conversion process on the gradation image data to convert the gradation into dithered image data. 2. A dither pattern information storage section, a gradation information storage section, and when converting a dither pattern into gradation information, read information from the dither pattern information storage section and output it to the gradation information storage section. When converting information into a dither pattern, the dither reads information from the gradation information storage section and writes it into the dither pattern information storage section.
2. The dither image data processing method according to claim 1, further comprising: a grayscale image data converter.