Image processing method and device for the same

• US 5,465,164 A
• Filed: 04/14/1992
• Issued: 11/07/1995
• Est. Priority Date: 04/15/1991
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sugiura, Susumu, Mita, Yoshinobu
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US07/868,103
• Time in Patent Office: 1,302 Days
• Field of Search: 358/448, 358/458, 358/433, 358/56, 358/80, 358/133, 358/135, 358/136, 358/500, 358/528, 358/434, 358/527, 358/138, 358/56, 358/426, 358/261.3, 358/261.4, 358/432 , 358/479, 358/909, 358/13, 358/85, 358/209
• US Class Current: 382/252
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/90 using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals

Abstract

Disclosed is an image processing device which comprises a conversion means for converting an image data to a space frequency component, a quantization means for quantizing the space frequency component converted by the conversion means, and a control means for controlling the quantization means so that a quantization error produced when the converted space frequency component is quantized by the quantization means is diffused to nearby space frequency components.

Claims

1. An image processing method for processing image data arranged in image blocks, comprising the step of:

converting image data to a space frequency component for each image block; and

diffusing a quantization error produced by quantizing a space frequency component of an image block to another space frequency component of the same image block.

3. An image processing method according to claim 1, wherein said quantization error is multi-dimensionally diffused to said other space frequency components.

4. An image processing method according to claim 1, further comprising the step of quantizing said space frequency component.

5. An image processing method according to claim 1, further comprising the step of assigning a Huffman code to said quantized space frequency component.

6. An image processing method according to claim 1, further comprising the step of transmitting said Huffman code.

2. An image processing device for processing image data arranged in image blocks, comprising:

conversion means for converting image data to a space frequency component for each image block;

quantization means for quantizing said space frequency component converted by said conversion means; and

control means for controlling said quantization means so that a quantization error produced by quantizing the space frequency component of an image block is diffused to another space frequency component of the same image block.

7. An image processing method, comprising the steps of:

converting image data having a first number of bits to image data having a lesser number of bits; and

diffusing an error produced in said conversion process to nearby image data and then converting the error-diffused image data into frequency component image data.

8. An image processing method according to claim 7, wherein the first converting step is an ADCT image compression/extension processing.

9. An image processing method for processing image data arranged in blocks, wherein the method is used in an ADCT image compression/extension processing, comprising the steps of converting image data to a space frequency component for each image block, quantizing a converted space frequency component and diffusing a quantized error produced by quantizing a space frequency component of a block to another frequency component of the image block.