Image compression method

• US 20040114809A1
• Filed: 11/05/2003
• Published: 06/17/2004
• Est. Priority Date: 12/11/2002
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Yong-Nam
• Application Number:
  US10/701,648
• Publication Number:
  US 20040114809A1
• Time in Patent Office: Days
• US Class Current: 382/232
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: H03M 7/3084 using adaptive string matching, e.g. the Lempel-Ziv method
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567

Abstract

Disclosed herein is a method for compressing an image using a permissible-error (PE) encoding method and a dynamic link-size encoding method. An image compression efficiency can be increased by selectively applying the permissible-error encoding method and the dynamic link-size encoding method to a zero loss compression method, for example, a Lempel-Ziv compression method.

Claims

1. An image compression method for increasing a data rate and decoding performance of an image to be transmitted, comprising the steps of:

a) determining whether respective codes corresponding to said image are repeated, encoding repeated codes of the corresponding codes into linked data indicative of a start position and number of the repeated codes, and encoding non-repeated codes of said corresponding codes into unlinked data indicative of the non-repeated codes; and

b) setting a linked data size indicative of an entire size of said linked data, consecutively arranging said linked data, arranging said linked data size upstream of said consecutively arranged linked data and arranging said unlinked data downstream of said consecutively arranged linked data.

2. An image compression method for increasing a data rate and decoding performance of an image to be transmitted, comprising the steps of:

a) determining whether respective codes corresponding to said image are repeated, encoding repeated codes of the corresponding codes into linked data indicative of a start position and number of the repeated codes, and encoding non-repeated codes of said corresponding codes into unlinked data indicative of the non-repeated codes; and

b) setting a permissible error with respect to each of said linked data and encoding said linked data within the range of the set permissible error.

3. The image compression method as set forth in claim 2, wherein said permissible error is variably set and said image is increased in its compression efficiency as said range of said permissible error increases.

4. An image compression method for increasing a data rate and decoding performance of an image to be transmitted, comprising the steps of:

a) initializing a position of a current pixel of said image to be encoded and a position of a previous pixel to be compared with said current pixel to find repeated patterns with respect to said current pixel;

b) comparing said current pixel position with said previous pixel position to determine whether said current pixel position is less than said previous pixel position;

c) obtaining differences between code values from said current pixel position to a certain pixel position and code values from said previous pixel position to just before said current pixel position if said current pixel position is determined to be less than said previous pixel position;

d) selecting one of said differences existing within the range of a set permissible error as a permissible value and determining whether said permissible value is repeated; and

e) if said permissible value is determined to be repeated, transforming the repeated permissible values into linked data including a start position and number of the repeated permissible values, and, if said permissible value is determined not to be repeated, maintaining the permissible value.

5. The image compression method as set forth in claim 4, wherein said permissible error is variably set and said image is increased in its compression efficiency as said range of said permissible error increases.

6. An image compression method for increasing a data rate and decoding performance of an image to be transmitted, comprising the steps of:

a) initializing a position of a current pixel of said image to be encoded and a position of a previous pixel to be compared with said current pixel to find repeated patterns with respect to said current pixel;

b) comparing said current pixel position with said previous pixel position to determine whether said current pixel position is less than said previous pixel position;

c) determining whether code values from said current pixel position to a certain pixel position and code values from said previous pixel position to just before said current pixel position are repeated, if said current pixel position is determined to be less than said previous pixel position;

d) transforming repeated codes of said code values into linked data including a start position and number of the repeated code values, and maintaining non-repeated codes of said code values as unlinked data;

e) setting information regarding an entire size of said linked data, consecutively arranging said linked data and arranging said entire size information of said linked data upstream of said consecutively arranged linked data; and

f) arranging said unlinked-data downstream of said consecutively arranged linked data.

7. The image compression method as set forth in claim 6, wherein said entire size of said linked data is any one of 4 bytes and 6 bytes.

8. An image compression method for increasing a data rate and decoding performance of an image to be transmitted, comprising the steps of:

a) initializing a position of a current pixel of said image to be encoded and a position of a previous pixel to be compared with said current pixel to find repeated patterns with respect to said current pixel;

b) comparing said current pixel position with said previous pixel position to determine whether said current pixel position is less than said previous pixel position;

c) obtaining differences between code values from said current pixel position to a certain pixel position and code values from said previous pixel position to just before said current pixel position if said current pixel position is determined to be less than said previous pixel position;

d) selecting one of said differences existing within the range of a set permissible error as a permissible value and determining whether said permissible value is repeated;

e) if said permissible value is determined to be repeated, transforming the repeated permissible values into linked data including a start position and number of the repeated permissible values, and, if said permissible value is determined not to be repeated, maintaining the permissible value; and

f) setting information regarding an entire size of said linked data, consecutively arranging said linked data, arranging said entire size information of said linked data upstream of said consecutively arranged linked data and arranging unlinked data downstream of said consecutively arranged linked data.

9. The image compression method as set forth in claim 8, wherein step e) includes the step of performing a permissible-error encoding operation, and step f) includes the step of performing a dynamic link-size encoding operation.

10. The image compression method as set forth in claim 9, wherein said permissible error is variably set and said image is increased in its compression efficiency as said range of said permissible error increases.

11. The image compression method as set forth in claim 10, wherein said entire size of said linked data is one of 4 bytes and 6 bytes.