Method and apparatus for dynamically selecting an image compression process based on image size and color resolution

• US 5,553,160 A
• Filed: 09/01/1994
• Issued: 09/03/1996
• Est. Priority Date: 09/01/1994
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Dawson, Bryan J.
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): Johns, Andrew W.
• Application Number:
  US08/299,893
• Time in Patent Office: 733 Days
• Field of Search: 382/166, 382/232, 382/239, 382/244, 382/286, 358/261.2, 358/430, 358/449, 358/539, 348/404
• US Class Current: 382/166
• CPC Class Codes: G06T 9/005 Statistical coding, e.g. Huffman, run length coding
• CPC Class Codes: G06T 9/007 Transform coding, e.g. discrete cosine transform
• CPC Class Codes: H04N 1/41 Bandwidth or redundancy reduction by scanning H04N1/17 ; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence

Abstract

A method and apparatus which dynamically selects an image compression process for an image to be transferred from a first agent to a second agent. The image being compressed has a particular size associated with it, which indicates the amount of storage space required to store the image, such as in the system memory or a mass storage device. The image also has a particular color resolution associated with it, which indicates the number of different colors which the image may contain. A particular image compression process is selected for the image based on its size and color resolution. In one embodiment, the present invention produces one of three possible outcomes. First, the image may remain uncompressed. Second, the image may be compressed using a lossless compression process, which reduces the size of the image while retaining all data for the image. Third, the image may be compressed using a lossy compression process, which reduces the size of the image by losing a small amount of data for the image.

Claims

1. A method for selecting an image compression process to compress an image, said method comprising the steps of:

(a) determining an uncompressed size of said image;

(b) determining a color resolution of said image; and

(c) selecting said image compression process based on the uncompressed size of said image and the color resolution of said image.

2. The method of claim 1, wherein said selected image compression process is a lossless data compression process which compresses said image while retaining all data for said image.

3. The method of claim 1, wherein said selected image compression process is a lossy data compression process which compresses said image by losing a small amount of data for said image.

4. The method of claim 1, wherein said step (c) comprises selecting a first data compression process which retains all data for said image, provided the color resolution of said image is below a predetermined value.

5. The method of claim 1, wherein said step (c) comprises the steps of:

compressing said image utilizing a first data compression process which retains all data for said image; and

determining a compression ratio for said image from said first data compression process.

6. The method of claim 5, wherein said step (c) further comprises the step of utilizing said first data compression process as said image compression process, provided said compression ratio is greater than a predetermined value, otherwise utilizing a second data compression process which loses a small amount of data for said image as said image compression process.

7. The method of claim 1, wherein said selecting step (c) further comprises selecting said image compression process based on a compression ratio corresponding to said image.

8. A method for selecting an image compression process to compress an image, said image having a size and a color resolution, said method comprising the steps of:

(a) determining the size of said image;

(b) determining the color resolution of said image; and

(c) selecting said image compression process based on the size of said image and the color resolution of said image, wherein said image compression process leaves said image uncompressed, provided the size of said image is less than a predetermined size.

9. A method for selecting an image compression process to compress an image, said image having a size and a color resolution, said method comprising the steps of:

(a) determining the size of said image;

(b) determining the color resolution of said image;

.

(c) compressing a predetermined portion of said image utilizing a first data compression process which reduces the size of said image while retaining all data for said image;

(d) determining a first compression ratio for said predetermined portion of said image from said first data compression process; and

(e) selecting said image compression process based on the first compression ratio.

10. The method of claim 9, wherein said step (c) further comprises the step of selecting a second data compression process as said image compression process which reduces the size of said image by losing a small amount of data for said image, provided said first compression ratio is greater than a first predetermined value, otherwise,

compressing said image utilizing said first data compression process,

determining a second compression ratio for said image from said first data compression process, and

selecting said first data compression process as said image compression process, provided said second compression ratio is greater than a second predetermined value, otherwise selecting said second data compression process as said image compression process.

11. An apparatus for selecting an image compression process to compress an image, wherein said apparatus is coupled to a user interface for displaying said image, said apparatus comprising:

a compression manager for

determining an uncompressed size of said image,

determining a color resolution of said image, and

selecting said image compression process based on the uncompressed size of said image and the color resolution of said image.

12. The apparatus of claim 11, wherein said compression manager selects an image compression process which retains all data for said image, provided the color resolution of said image is below a predetermined value.

13. The apparatus of claim 11, wherein said compression manager is also for:

compressing said image utilizing a first data compression process;

determining a compression ratio for said image from said first data compression process; and

utilizing said first data compression process as said image compression process, provided said compression ratio is greater than a predetermined value, otherwise utilizing a second data compression process which loses a small amount of data for said image as said image compression process.

14. The apparatus of claim 11, wherein said compression manager is also for:

compressing a predetermined portion of said image utilizing a first data compression process;

determining a first compression ratio for said predetermined portion of said image from said first data compression process; and

selecting a second data compression process as said image compression process, provided said first compression ratio is greater than a first predetermined value, otherwise,

compressing said image utilizing said first data

compression process,

determining a second compression ratio for said image

from said first data compression process, and

selecting said first data compression process as said image compression process, provided said second compression ratio is greater than a second predetermined value, otherwise selecting said second data compression process as said image compression process.

15. An apparatus for selecting an image compression process to compress an image, said image having a size and a color resolution, wherein said apparatus is coupled to a user interface for displaying said image, said apparatus comprising:

a compression manager for

determining the size of said image,

determining the color resolution of said image, and

selecting said image compression process based on the size of said image and the color resolution of said image, wherein said image_ compression process leaves said image uncompressed, provided the size of said image is less than a predetermined size.

16. A computer system comprising:

a central processing unit (CPU);

a mass storage device;

a bus coupled to said CPU and said mass storage device; and

a compression manager for selecting an image compression process to compress an image, said image having an uncompressed size and a color resolution, said selecting being based on the uncompressed size and the color resolution of said image.

17. The system of claim 16, wherein said compression manager selects an image compression process which retains all data for said image, provided the color resolution of said image is below a predetermined value.

18. The system of claim 16, wherein said compression manager is also for:

compressing said image utilizing a first data compression process;

determining a compression ratio for said image from said first data compression process; and

utilizing said first data compression process as said image compression process, provided said compression ratio is greater than a predetermined value, otherwise utilizing a second data compression process which loses a small amount of data for said image as said image compression process.

19. The system of claim 16, wherein said compression manager is also for:

compressing a predetermined portion of said image utilizing a first data compression process;

determining a first compression ratio for said predetermined portion of said image from said first data compression process; and

selecting a second data compression process as said image compression process, provided said compression ratio is greater than a first predetermined value, otherwise,

compressing said image utilizing said first data compression process,

determining a second compression ratio for said image from said first data compression process, and

selecting said first data compression process as said image compression process, provided said second compression ratio is greater than a second predetermined value, otherwise selecting said second data compression process as said image compression process.

20. A computer system comprising:

a central processing unit (CPU);

a mass storage device;

a bus coupled to said CPU and said mass storage device;

an interconnecting device coupled to said bus to transfer data from said computer system to an agent; and

a compression manager for selecting an image compression process to compress an image, said image having a size and a color resolution, said selecting being based on the size and the color resolution of said image, wherein said image compression process leaves said image uncompressed, provided the size of said image is less than a predetermined size.

21. A computer-readable medium having stored thereon a program of instructions executable by a processor, the program of instructions including sequences of instructions which, when executed by the processor, cause said processor to perform the steps of:

(a) determining an uncompressed size of an image;

(b) determining a color resolution of said image; and

(c) selecting an image compression process for compressing said image, wherein said selecting is based on the uncompressed size of said image and the color resolution of said image.

22. The computer-readable medium of claim 21, wherein said selecting step (c) comprises selecting an image compression process which leaves said image uncompressed, provided the uncompressed size of said image is less than a predetermined size.

23. The computer-readable medium of claim 21, wherein said selecting step (c) comprises the steps of:

compressing said image using a lossless data compression process; and

determining a compression ratio for said image from said lossless data compression process.

24. The computer-readable medium of claim 21, wherein said selecting step (c) comprises the steps of:

compressing a predetermined portion of said image using a lossless data compression process; and

determining a compression ratio for said predetermined portion of said image from said lossless data compression process.

25. The computer-readable medium of claim 21, wherein said selecting step (c) further comprises selecting said image compression process based on a compression ratio corresponding to said image.