EP0429283A2
Expired / Lapsed
EP
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Image processing apparatus
Assignee: Canon Inc
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Filing: 1990-11-19
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Granted: —
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Expires: 2010-11-19
Abstract
Abstract An image processing apparatus has a memory device for storing pixel image data including both halftone image data such as data of image of a photograph having a gradation and line image data such as data of text containing characters. The storage is conducted on the basis of blocks each having a predetermined number of pixels. The mean information quantity of the halftone image data per pixel stored in the memory means is not greater than the information quantity of the line image data per pixel stored in the memory means. The halftone image data being compressed on the basis of the block. Therefore, both the halftone image data and line image data can be stored in a small memory by using common addresses, without causing any degradation of the image quality.
Inventors
- 👤 Hisashi C/O Canon Kabushiki Kaisha Ishikawa
- 👤 Hideo C/O Canon Kabushiki Kaisha Homma
- 👤 Yoshitake C/O Canon Kabushiki Kaisha Nagashima
- 👤 Takashi C/O Canon Kabushiki Kaisha Saito
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 11:26
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/41; G; G06; G06T; G06T9/00; G06T9/005; H04N1/4105; H04N1/46; H04N1/64; H04N1/642
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
81 words
An image processing apparatus comprising: memory means for storing, on the basis of blocks each having a predetermined number of pixels, pixel image data including both halftone image data and line image data; wherein the mean information quantity of said halftone image data per pixel stored in said memory means is not greater than the information quantity of said line image data per pixel stored in said memory means, said halftone image data being compressed on the basis of said block.
Claim 2
Dependent Claim
81 words
An image processing apparatus comprising: memory means for storing, on the basis of blocks each having a predetermined number of pixels, pixel image data including both halftone image data and line image data; wherein the mean information quantity of said halftone image data per pixel stored in said memory means is not greater than the information quantity of said line image data per pixel stored in said memory means, said halftone image data being compressed on the basis of said block.
Claim 3
Dependent Claim
86 words
An image processing apparatus comprising: memory means for storing, on the basis of blocks each having a predetermined number of pixels, pixel data of one frame including both halftone image data and line image data; means for controlling writing of said data in said memory means; wherein said memory means store said halftone image pixel data while compressing the data quantity thereof, and said control means uses common addresses in writing said halftone image pixel data and said line image pixel data in said memory means.
Claim 4
Dependent Claim
86 words
An image processing apparatus comprising: memory means for storing, on the basis of blocks each having a predetermined number of pixels, pixel data of one frame including both halftone image data and line image data; means for controlling writing of said data in said memory means; wherein said memory means store said halftone image pixel data while compressing the data quantity thereof, and said control means uses common addresses in writing said halftone image pixel data and said line image pixel data in said memory means.
Claim 5
Dependent Claim
73 words
An image processing apparatus comprising: memory means for storing data carried by pixels; judging means for judging whether said pixel data read from said memory means is a halftone image data or not; and halftone processing means for conducting a halftone processing on pixel data which has been judged as being halftone image data by said judging means, using peripheral pixel data on the pixels around the pixels carrying said halftone image data.
Claim 6
Dependent Claim
73 words
An image processing apparatus comprising: memory means for storing data carried by pixels; judging means for judging whether said pixel data read from said memory means is a halftone image data or not; and halftone processing means for conducting a halftone processing on pixel data which has been judged as being halftone image data by said judging means, using peripheral pixel data on the pixels around the pixels carrying said halftone image data.
Claim 7
Dependent Claim
99 words
An image processing apparatus comprising: judging means for judging whether input data is halftone image data or not; coding means for extracting, when said input data is judged to be halftone image data by said judging means, a representative color of the input data on the basis of pixel blocks each having a predetermined number of pixels, and coding the extracted representative color; a first memory for storing the code coded by said coding means; and a second memory for storing said input data when said input data is judged by said judging means to be halftone image data.
Claim 8
Dependent Claim
99 words
An image processing apparatus comprising: judging means for judging whether input data is halftone image data or not; coding means for extracting, when said input data is judged to be halftone image data by said judging means, a representative color of the input data on the basis of pixel blocks each having a predetermined number of pixels, and coding the extracted representative color; a first memory for storing the code coded by said coding means; and a second memory for storing said input data when said input data is judged by said judging means to be halftone image data.
Claim 9
Dependent Claim
72 words
An image processing apparatus comprising: memory means for storing, on the basis of blocks each having a predetermined number of pixels, one frame pixel data including both halftone image data and line image data; and control means for reading pixel data of a predetermined area out of the pixel data stored in said memory means; wherein said pixel data read by said control means includes halftone image data and line image data.
Claim 10
Dependent Claim
72 words
An image processing apparatus comprising: memory means for storing, on the basis of blocks each having a predetermined number of pixels, one frame pixel data including both halftone image data and line image data; and control means for reading pixel data of a predetermined area out of the pixel data stored in said memory means; wherein said pixel data read by said control means includes halftone image data and line image data.
Claim 11
Dependent Claim
29 words
An image processing apparatus according to any one of claims 1 to 3 or 5, further comprising halftone processing means for supplying said memory means with halftone image data.
Claim 12
Dependent Claim
24 words
An image processing apparatus according to claim 6, wherein said halftone processing means generates halftone image data representing gradation information of the respective blocks.
Claim 13
Dependent Claim
23 words
An image processing apparatus according to claim 6, said halftone image processing means includes means for compressing image data on the block basis.
Claim 14
Dependent Claim
26 words
An image processing apparatus according to either of claims 1 or 2, further comprising supply means for supplying said line image data to said memory means.
Claim 15
Dependent Claim
32 words
An image processing apparatus according to any one of claims 1, 2 or 5 further comprising judging means for judging whether said image data is halftone image data or line image data.
Claim 16
Dependent Claim
37 words
An image processing apparatus according to either of claims 1 or 2, further comprising restoring means for reading the image data from said memory means and restoring gradation information of the pixels from the read image data.
Claim 17
Dependent Claim
29 words
An image processing apparatus according to claim 11, further comprising image forming means for forming an image in accordance with the pixel gradation information restored by said restoring means.
Claim 18
Dependent Claim
27 words
An image processing apparatus according to claim 3, further comprising image forming means for forming an image in accordance with the output from said halftone processing means.
Claim 19
Dependent Claim
21 words
An image processing apparatus according to claim 12 or 13, wherein said image forming means forms said image by electrophotographic process.
Claim 20
Dependent Claim
44 words
An image processing apparatus according to claim 12, wherein said image forming means is a printer having a print head of the type which discharges a droplet by a force produced by membrane boiling of a recording medium caused by application of heat energy.
Claim 21
Dependent Claim
24 words
An image processing apparatus according to either of claims 3 or 4, wherein said judging means conducts the judgment by analyzing a predetermined command.
Claim 22
Dependent Claim
31 words
An image processing apparatus according to claim 4, further comprising restoring means for reading data from said first and second memories and for restoring pixel color information from the read data.
Claim 23
Dependent Claim
29 words
An image processing apparatus according to claim 17, further comprising image forming means for forming an image in accordance with the pixel gradation information restored by said restoring means.
References Cited (Backward Citations)
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