Method and systems for thumbnail generation, and corresponding computer program product

Patent metadata

Field	Value
Publication number	US-9105111-B2
Application number	US-201313759991-A
Country	US
Kind code	B2
Filing date	Feb 5, 2013
Priority date	Apr 30, 2009
Publication date	Aug 11, 2015
Grant date	Aug 11, 2015

Abstract

An embodiment of a consumer electronics product having a thumbnail display feature includes a system for generating and storing thumbnails having a given size from images, such as JPEG images, for which a spatial frequency domain representation is available. The system includes a zooming processor to reduce the size of the images by zooming. The zooming processor is configured to perform both spatial frequency domain zooming to approximate the desired thumbnail size and then image pixel domain zooming to fit the desired thumbnail size. The product includes cache storage configured to store a plurality of thumbnails in a file system as free blocks in the file system, so that file system data structures are left unchanged.

First claim

What is claimed is:

1. A method, comprising:
scaling an encoded image by changing by a first factor at least one dimension of transform-domain blocks that represent the encoded image;
decoding the scaled encoded image into a decoded image; and
scaling the decoded image by changing by a second factor at least one dimension of the decoded image;
wherein scaling the encoded image comprises reducing by the first factor the at least one dimension of the transform-domain blocks, the at least one dimension being an integer multiple of the first factor.

2. The method of claim 1 wherein the first and second factors are different.

3. The method of claim 1 wherein at least one of the first and second factors equals unity.

4. The method of claim 1 wherein the first and second factors are greater than unity.

5. The method of claim 1 wherein the first and second factors are less than unity.

6. The method of claim 1 wherein:
one of the first and second factors is greater than unity; and
the other of the first and second factors is less than unity.

7. The method of claim 1 wherein scaling the encoded image comprises changing at least two dimensions of the transform-domain blocks by the first factor.

8. The method of claim 1 wherein scaling the decoded image comprises changing at least two dimensions of the decoded image by the second factor.

9. The method of claim 1 wherein scaling the encoded image further comprises reducing by the first factor at least two dimensions of the transform-domain blocks, the at least two dimensions being respective integer multiples of the first factor.

10. An integrated circuit, configured:
to scale an encoded image by changing by a first factor at least one dimension of transform-domain blocks that represent the encoded image including reducing by the first factor the at least one dimension of the transform-domain blocks, the at least one dimension being an integer multiple of the first factor;
to decode the scaled encoded image into a decoded image; and
to scale the decoded image by changing by a second factor at least one dimension of the decoded image;
to store the decoded image in a memory.

11. The integrated circuit of claim 10 wherein the integrated circuit is further configured to reduce by the first factor at least two dimensions of the transform-domain blocks, the at least two dimensions being respective integer multiples of the first factor.

12. A system, comprising:
a memory; and
a processor coupled to the memory and configured:
to scale an encoded image by changing by a first factor at least one dimension of transform-domain blocks that represent the encoded image including reducing by the first factor the at least one dimension of the transform-domain blocks, the at least one dimension being an integer multiple of the first factor;
to decode the scaled encoded image into a decoded image;
to scale the decoded image by changing by a second factor at least one dimension of the decoded image; and
to store the decoded image in the memory.

13. The system of claim 12 wherein the memory and the processor are disposed on a same integrated-circuit die.

14. The system of claim 12 wherein the memory and the processor are disposed on respective integrated-circuit dies.

15. The system of claim 12 , wherein the first factor corresponds to a spatial frequency domain factor.

16. The system of claim 12 , wherein the second factor corresponds to an image pixel domain factor.

17. The system of claim 12 , further comprising a cache storage in the memory configured to store the encoded image in a file system as a free block such that file system data structures are left unchanged.

18. The system of claim 12 , further comprising a cache storage in the memory configured to store the encoded image as a linked list of storage blocks.

19. A method, comprising:
scaling an encoded image by changing by a first factor at least one dimension of transform-domain blocks that represent the encoded image;
decoding the scaled encoded image into a decoded image;
scaling the decoded image by changing by a second factor at least one dimension of the decoded image; and
wherein changing by the first factor at least one dimension of the transform-domain blocks comprises changing by the first factor a number of transform coefficients along the at least one dimension, the number of transform coefficients being an integer multiple of the first factor.

20. The method of claim 19 wherein the first and second factors are different.

21. The method of claim 19 wherein at least one of the first and second factors equals unity.

22. The method of claim 19 wherein the first and second factors are either greater than unity or the first and second factors are less than unity.

Assignees

• Stmicroeletronics S R L
• St Microelectronics Srl

Inventors

• Pascali Stefano
• Palmieri Andrea Riccardo

Classifications

• G06T3/40

  Scaling of whole images or parts thereof, e.g. expanding or contracting · CPC title

• G06T1/60 Primary

  Memory management · CPC title

• G06T9/00

  Image coding (bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00) · CPC title

• G06T3/0012

  Physics · mapped topic

• G06T3/04 Primary

  Context-preserving transformations, e.g. by using an importance map (panospheric to cylindrical image transformations G06T3/12) · CPC title