JPH01191273A - Picture data compressing method - Google Patents

Abstract

PURPOSE:To compress picture data under a state capable of reproducing a dot at high speed by dividing the picture data to be compressed by considering a prescribed dot matrix block as a unit, converting it to vector data for every block and then encoding and compressing. CONSTITUTION:When a picture editor 13 inputs the picture data to be compressed from a picture input machine 12, it vertically and horizontally divides said data (3,072X3,072 dots) to the processing blocks (d1-d9) of 1,024X1,024 dot units of the processing units of vector data, manages the numbers of the respective blocks and stores in a divided image picture storing part 14. The picture data of the respective blocks d1-d9 stored in this divided image picture storing part 14 is read for one block unit and converted to the vector data by a vector data forming circuit 15. The formed vector data for respective blocks d1-d9 is encoded and compressed by vector data compressing circuit 16. Thereby, the image data can be compressed at high speed under the state capable of reproducing the dot by the use of a vector data processing technique.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention is directed to, for example, 307'2
The present invention relates to an image data compression method for compressing relatively large dot matrix image data such as 96x4096 dots using vector data processing technology in a state where high-speed reproduction processing is possible.

(Prior Art) Conventionally, when binary image data of a relatively large dot matrix structure (for example, 3072 x 3072 dots, 4098 x 4096 dots, or more) read by an image scanner or the like is compressed using existing image compression technology, A large amount of time was wasted on image playback that involved decompression processing.

(Problems to be Solved by the Invention) As mentioned above, conventionally, when compressing binary image data in a relatively large dot matrix structure read by an image scanner etc., it takes a very large amount of time to reproduce the image along with decompression processing. I was spending a lot of time.

The present invention has been made in view of the above-mentioned circumstances, and provides an image data compression method that can compress relatively large dot matrix image data using vector data processing technology in a state that enables high-speed dot reproduction processing. The purpose is to provide.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention provides a means for dividing image data to be compressed into predetermined dot matrix sections, and a means for dividing image data to be compressed into predetermined dot matrix partitions, and The image data to be compressed is divided into predetermined dot matrix sections by means of converting each of the image data into vector data, and means for encoding, compressing and storing the vector data of each section. Then, each section is converted to vector data and then coded and compressed. 2. The relatively large dot matrix image data is compressed in a state that allows for high-speed dot reproduction processing using vector data processing technology. can be carried out.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing an example of division of an image to be subjected to compression processing.

In the figure, reference numeral 11 denotes a manuscript paper IL on which an image to be subjected to compression processing is recorded. Reference numeral 12 denotes a manuscript paper IL on which an image to be subjected to compression processing is recorded. This is an image input device that reads 3072 x 3072 dots. Reference numeral 13 denotes a processing section (di~
This is an image editing machine that divides the image vertically and horizontally into d9) and manages numbers for each division. Reference numeral 14 denotes a divided image storage unit that stores the image data of each section (di to d9) divided by the image editing machine 12 in the form of dot images, and here, like the compressed vector data storage unit described later, it is stored on a hard disk. It is provided in the device (HDD). 15 is a vector data generation circuit that converts the divided image data stored in the divided image storage section 14 into vector data for each section (dl to d9); 16 is a vector data generation circuit that converts the divided image data stored in the divided image storage section 14 into vector data; Each section (di-
d9) A vector data compression circuit that encodes and compresses the vector data, 17 is the vector data compression circuit 16 described above.
This is a divided image storage unit that stores compressed vector data that has been coded and compressed.

FIG. 3 is a block diagram for explaining a vector data reproduction method for dot expansion of the compressed vector data stored in the divided image storage section 17 to create a dot image corresponding to the read image. In the figure, 18 is a reproducing circuit that decompresses the compressed vector data stored in the divided image storage section 17 and reproduces it into dot image data, and 19 is a circuit that expands the dot image data obtained from the reproducing circuit 18 into dot image data. This is a dot image expansion buffer.

Here, the image data compression processing operation according to one embodiment will be described with reference to FIGS. 1 to 3 above.

The image input device 12 scans the manuscript paper Il and converts the image recorded on the paper 11 to be compressed to a predetermined resolution, for example, 3072X as shown in FIG. 2(a).
The image is read at a resolution of 3072 dots and sent to the image editing machine 13. When the image editing machine 13 inputs image data to be compressed from the image input machine 12, the image editing machine 13 inputs image data to be compressed.
ao72x 3072 dots) as shown in Figure 2(b), 1024X
Vertical and
The image is divided horizontally, and each section is numbered and stored in the divided image storage section 14.

Each section (
dl, to d9) is read out in units of sections, and converted into vector data by the vector data generation circuit 15.

The vector data generation process in this case is realized by first extracting the outline of the image, tracing the direction of the outline, and obtaining data on the start and end point coordinates and length of each outline (patent application (Refer to Publication No. 1982-21003 "Contour Extraction Method").

Each section (
The vector data for each of di to d9) is conidized and compressed by the vector data compression circuit 16, and then stored in the divided image storage section 17.

In this way, the high-resolution image data (3072 x 3072 dots) obtained from the image machine I2 is divided vertically and horizontally into processing sections (di to d9) of 1024 x 1024 dots, which are the processing units of vector data. divided,
After each section is converted into vector data, it is encoded and compressed and stored in the divided image storage section 17.

Next, the processing operation for reproducing a dot image from the compressed vector data stored in the divided image storage section 17 as described above will be explained with reference to FIG.

The reproducing circuit 18 reads the compressed vector data stored in the divided image storage section 17 one section at a time in a fixed order of sections, generates dot image data from the compressed vector data, and expands the dot image data onto the dot image expansion buffer 19. I'm going to go. The playback mechanism at this time is
Since it is disclosed in Publication No. 2878 entitled "Vector Font Reproducing Apparatus", detailed explanation will be omitted here.

The conversion from compressed vector data to a dot image and the dot expansion process are performed for all sections (dL to d9).
Through repeated execution, a dot image as shown in FIG. 2(a) is reproduced on the dot image development buffer 19.

As described above, relatively large dot matrix image data can be compressed using vector data processing technology in a state where dot reproduction processing can be performed at high speed.

Incidentally, in the above embodiment, for convenience of explanation, image modification during image reproduction processing is not mentioned, but for example,
Various types of image modification (
For example, enlarge/reduce.

(rotation, italicization, etc.), and in this case, the most efficient image division unit is set in consideration of the processing on the reproduction circuit side.

[Effects of the Invention] As detailed above, according to the image data compression method of the present invention, the image data to be compressed is divided into units of predetermined dot matrix sections, and It has a means for converting the image data of each section into vector data, and a means for encoding, compressing and storing the vector data of each section, and converts the image data to be compressed in units of predetermined dot matrix sections. By dividing the image data into vector data, converting each section into vector data, and then encoding and compressing the image data, relatively large dot matrix-structured image data can be reproduced into dots at high speed using vector data processing technology. Can be compressed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 (
a) and (b) are diagrams for explaining image division processing in the above embodiment, respectively, and FIG. 3 is a diagram for explaining image reproduction processing in the above embodiment. 11... Manuscript paper, 12... Image input device, 13...
・Image editing machine, 14...Divided image storage unit, 1
5... Divided image storage unit, 16... Vector data compression circuit, 17... Divided image storage unit,
18... Reproduction circuit, 19... Dot image expansion buffer. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] An image data compression method characterized in that image data to be compressed is divided into predetermined dot matrix sections, each section is converted into vector data, and then encoded and compressed and stored.