METHOD FOR TRANSFERRING AND DISPLAYING COMPRESSED IMAGES

• US 20010019630A1
• Filed: 03/31/1999
• Published: 09/06/2001
• Est. Priority Date: 07/14/1994
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: America Online Inc. (Warner Bros. Discovery, Inc.)
• Inventors: JOHNSON, STEPHEN G.
• Granted Patent: US 6,453,073 B2
• Time in Patent Office: Days
• US Class Current: 382/232
• 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 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/80 Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation H04N19/635, H04N19/86 take precedence
• CPC Class Codes: H04N 19/94 Vector quantisation

Abstract

An image of certain resolution higher than possible in a single transmission over a finite bandwidth channel is obtained by transferring a progressively-rendered, compressed image. Initially, a low quality image is compressed and transmitted over a finite bandwidth channel. Then, a successively higher resolution image information is compressed at a source and is transmitted. The successively higher resolution image information received at the destination end is used to display a higher resolution image at the destination end.

Claims

1. A method of transferring a progressively-rendered, compressed image, over a finite bandwidth channel, comprising:

producing a coarse quality compressed image at a source and transmitting said coarse quality compressed image over a channel as a first part of a transmission to a destination end;

receiving the coarse quality compressed image at a receiver at the destination end at a first time and displaying an image based on said coarse quality compressed image on a display system of the receiver when received at said first time;

creating additional information about the image, at the source end, from which a standard quality image can be displayed, said standard quality image being of a higher quality than said coarse quality image, and sending compressed information over said channel indicative of information for said standard quality image, said sending said standard quality image information occurring subsequent in time to said sending of all of said information for said coarse quality image;

receiving said standard quality information at the receives at a second time, subsequent to the first time, and decompressing said standard quality image information, to improve the quality of the image displayed on said display system, and to display said standard quality image;

obtaining further information about the image beyond the information in said standard quality image, to provide an enhanced quality image, and compressing said information for said enhanced quality image, said enhanced quality image having more image details than said standard quality image;

transmitting said information for said enhanced quality image, at a time subsequent to transmitting said information for said coarse quality image and said standard quality image; and

receiving said enhanced quality image information at said receiver, at a third time subsequent to said first and second times, and updating a display on said display system to display the additional enhanced quality image.

2. A method as in

claim 1

, wherein said producing the coarse quality image uses a different compression technique than said creating additional information indicative of the standard quality image.

3. A method as in

claim 1

, wherein said coarse quality image includes information indicative of a miniature version of an original image, and said displaying the coarse quality image comprises interpolating said miniature to a size of the original image and displaying said image.

4. A method as in

claim 2

, wherein said creating additional information comprises determining a characteristic of the image, determining which of a plurality of different as compression technique will best compress the characteristic determined;

and compressing said image using the determined technique.

5. A method as in

claim 4

, further comprising determining a plurality of areas in said image, and determining, for each area, which of the plurality of different compression techniques will optimize the compression ratio.

6. A method as in

claim 5

, further comprising interleaving and channel encoding different portions of the compressed image.

7. A method as in

claim 5

, wherein said compression technique include vector quantization and discrete cosine transform.

8. A method as in

claim 3

, wherein said obtaining a miniature comprises decimating along vertical and horizontal axes.

9. A method of transmitting and displaying a compressed image comprising:

first obtaining and sending a first layer of information indicative of a compressed miniature image at a first time;

first receiving said first layer at said decoder end and decompressing and displaying a first coarse image indicative thereof;

second obtaining and sending information indicative of a compressed improved resolution image having more details than said first coarse image, and transmitting said information at a second time subsequent to said first time; and

second receiving and decompressing said improved resolution image information to provide an updated display which improves the resolution of said first coarse image.

10. A method as in

claim 9

, wherein said obtaining coarse information comprises:

transmitting information indicative of a compressed miniature of the image;

receiving the compressed miniature of the image;

interpolating the compressed miniature of the image into a full sized image; and

displaying the full sized image.

11. A method as in

claim 10

, wherein the first coarse image is compressed using a first compression technique and the second image is compressed using a second compression technique which is different from the first compression technique.

12. A method as in

claim 11

, further comprising determining which of a plurality of different image compression technique will most efficiently code information indicative of said image.

13. A method as in

claim 12

, wherein said determining uses fuzzy logic technique.

14. A method as in

claim 11

, wherein said first obtaining comprises decimating data on the image to form a reduced quality image, fitting the decimated data to a first model which partially restores source image detail lost by decimation, and calculating reconstruction values from the fitting.

15. A method as in

claim 14

, further comprising using said reconstruction weights to interpolate the decimated data into a full sized image while minimizing a mean squared error between original image components and interpolated image components.

16. A method as in

claim 11

, wherein said first step comprises forming miniature versions of the original source image for each of a plurality of primary colors.

17. A method as in

claim 9

, wherein said first obtaining comprises obtaining a miniature image, and further comprising analyzing the miniature image to classify the image into one of a plurality of classes indicative of which of a plurality of compression techniques will best compress said image.