Efficient embedded image and video compression system using lifted wavelets

• US 6,466,698 B1
• Filed: 03/25/1999
• Issued: 10/15/2002
• Est. Priority Date: 03/25/1999
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Creusere, Charles D.
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): SHERALI, ISHRAT I
• Application Number:
  US09/276,181
• Time in Patent Office: 1,300 Days
• Field of Search: 382/240, 382/244, 382/232-233, 375/240.19, 375/240.25, 375/240.11, 375/240.18, 375/240.2, 358/426, 358/432, 709/203, 709/217
• US Class Current: 382/240
• CPC Class Codes: G06T 9/007 Transform coding, e.g. discrete cosine transform

Abstract

An image compression system for implementing a zerotree wavelet compression algorithm. The compression system uses a wavelet based coding system which takes advantage of the correlation between insignificant coefficients at different scales.

Claims

1. A method for converting an image, comprising the steps of:

acquiring an image;

storing the acquired image as a data array in a memory system;

progressively replacing pixel elements of the stored data array with transform coefficient elements through the lifted transformation;

scanning the transform coefficients to create an embedded symbol stream; and

,

losslessly encoding the embedded symbol stream to create an embedded bit stream.

2. The method of claim 1, further comprising the step of:

transmitting the created embedded bit stream.

3. The method of claim 1, further comprising the step of:

storing the created embedded bit stream in a memory system.

4. The method of claim 1, wherein the step of scanning the transform coefficients comprises a predetermined deterministic order.

5. The method of claim 1, wherein the step of scanning the transform coefficients comprises a symbol generation process.

6. The method of claim 1, wherein the symbol generation process comprises the step of storing residual values in a memory location that previously contained its associated wavelet transform coefficient.

7. The method of claim 1, wherein the step of scanning the transform coefficients comprises from about 3 or more additional bits per data array element used to temporarily store status information in creating the embedded bit stream.

8. The method of claim 1, wherein the step of scanning the transform coefficients comprises accessing the wavelet coefficient data array with absolute addressing.

9. The method of claim 1, wherein the step of scanning the transform coefficients comprises specifying a search order within each zerotree through a lookup table with the size of the lookup table dependant on the depth of the wavelet decomposition used.

10. The method of claim 1, wherein the embedded symbol stream is created using zerotree parent and child locations accessed through direct algebraic calculation.

11. The method of claim 1, further comprising the steps of:

losslessly decoding the bits to create a sequence of symbols;

converting the sequence of symbols into an array wavelet coefficients that describes the acquired image;

converting the coefficient array into a pixel array; and

,

outputting the resultant image.

12. The method of claim 11, wherein the step of converting the sequence of symbols successively generates approximations of the wavelet coefficients placed in a stored data array and performs an inverse lifted transform thereon.

13. The method of claim 11, wherein the step of converting the sequence of symbols comprises from about 3 or more additional bits per data array element used to temporarily store status information.

14. The method of claim 11, wherein the step of converting the sequence of symbols comprises accessing the wavelet coefficient data array with absolute addressing.

15. The method of claim 11, wherein the step of converting the sequence of symbols comprises specifying a search order within each zerotree through a lookup table with the size of the lookup table dependant on the depth of the wavelet decomposition used.

16. The method of claim 11, wherein the zerotree parent and child locations are accessed through direct algebraic calculation.