Methods and apparatus for partitioning transform data

• US 6,925,208 B1
• Filed: 05/04/2002
• Issued: 08/02/2005
• Est. Priority Date: 05/04/2002
• Status: Active Grant

• Current Assignee: Stentor, Inc. (Koninklijke Philips N.V.)
• Original Assignee: Stentor, Inc. (Koninklijke Philips N.V.)
• Inventors: Huffman, John C.
• Primary Examiner(s): Do, Anh Hong
• Application Number:
  US10/138,956
• Time in Patent Office: 1,186 Days
• Field of Search: 382/232, 382/299, 382/305, 382/233, 382/240, 345/1.2, 345/3.3, 709/247
• US Class Current: 382/232
• CPC Class Codes: G16H 30/20 for handling medical images, e.g. DICOM, HL7 or PACS
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/129 Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO]
• CPC Class Codes: H04N 19/162 User input
• CPC Class Codes: H04N 19/167 Position within a video image, e.g. region of interest [ROI]
• CPC Class Codes: H04N 19/1883 the unit relating to sub-band structure, e.g. hierarchical level, directional tree, e.g. low-high [LH], high-low [HL], high-high [HH]
• CPC Class Codes: H04N 19/62 by frequency transforming in three dimensions H04N19/63 takes precedence
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/635 characterised by filter definition or implementation details
• CPC Class Codes: H04N 19/64 characterised by ordering of coefficients or of bits for transmission
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards

Abstract

Transform data is partitioned to more efficiently process requests in a server to transfer source data to a client. The transform data, generated from source data, comprises spatially related coefficients such that a block of coefficients permits reconstruction of identifiable portions of the source data. The transform data is partitioned into a plurality of partitions of coefficients. Each partition consists of coefficients for reconstruction of an identifiable portion of the source data. The client generates a request for one or more partitions of coefficients. The client request is sent to the server. The server extracts the partitions of coefficients set forth in the request, and transfers the partitions of coefficients to the client. Techniques for partitioning of transform data to support lossy compression are disclosed.

Claims

1. A method for transferring source data from a server to a client, the method comprising the steps of;

generating, from the source data, transform data comprising spatially related coefficients such that a block of coefficients permit reconstruction of identifiable portions of the source data;

partitioning the transform data into a plurality of partitions of coefficients, each partition comprising coefficients for reconstruction of an identifiable portion of the source data;

generating, at a client, a request for at least one partition of the coefficients of the source data;

transferring, from the client to a server, the request;

extracting, at the server, the at least one partition of coefficients set forth in the request;

transferring, from the server to the client, the at least one partition of coefficients; and

reconstructing the source data at the client from the transform data.

2. The method as set forth in claim 1, further comprising the steps of:

storing the partitions of coefficients in a permanent storage medium; and

storing information to individually access the partitions of coefficients.

3. The method as set forth in claim 2, wherein:

the step of extracting, at the server, the partitions of coefficients set forth in the request comprises the step of obtaining the locations for the partitions of coefficients in the permanent storage medium; and

the step of transferring from the server to the client the partitions of coefficients comprises the step of transferring the partitions of coefficients from the permanent storage medium to the client.

4. The method as set forth in claim 1, further comprising the steps of:

generating, at the client, the request to include at least one quantization value for the at least one partition of coefficients;

quantizing, at the server, the partitions of coefficients, in accordance with the quantization value;

to generate quantized partitions of coefficients;

compressing the quantized partitions of coefficients to generate compressed partitions of coefficients; and

de-compressing the compressed partitions of coefficients at the client to recover the partitions of coefficients.

5. The method as set forth in claim 1, further comprising the step of caching the partitions of coefficients at the client.

6. The method as set forth in claim 5, further comprising the steps of:

generating, at the client, a second request for the partition of coefficients from a prior request, the prior request including a first quantization value for the partition of coefficients and the second request including a second quantization value for the partition of coefficients;

transferring, from the client to a server, the second request;

extracting, at the server, the partition of coefficients identified in the second request;

quantizing, at the server, the partitions of coefficients in the second request, in accordance with the second quantization value;

to generate second quantized partitions of coefficients;

generating a second compressed partition of coefficients from the second quantized partitions of coefficients;

transferring, from the server to the client, the second compressed partition of coefficients;

retrieving a first quantized partition of coefficients from the cache;

de-compressing the second compressed partition of coefficients to generate the second quantized partition of coefficients at the client;

generating a first and a second de-quantized coefficient blocks by multiplying the first and second quantized partition of coefficients by the first and second quantization values, respectively;

generating an aggregate partition of coefficients by adding the first de-quantized partition of coefficients with the second de-quantized partition of coefficients; and

reconstructing the source data at the client from the aggregate partition of coefficients.

7. The method as set forth in claim 1, wherein the source data comprises a source image.

8. The method as set forth in claim 7, wherein the source image comprises a medical image.

9. A method for processing data at a server, the method comprising the steps of:

generating, from the source data, transform data comprising spatially related coefficients such that a block of coefficients permit reconstruction of identifiable portions of the source data;

partitioning the transform data into a plurality of partitions of coefficients, each partition comprising coefficients for reconstruction of an identifiable portion of the source data;

receiving, from a client, a request for at least one partition of the coefficients of the source data;

extracting, at the server, the partition of coefficients set forth in the request; and

transferring, from the server to the client, the partition of coefficients.

10. The method as set forth in claim 9, further comprising the steps of:

storing the partitions of coefficients in a permanent storage medium; and

storing information to individually access the partitions of coefficients.

11. The method as set forth in claim 10, wherein:

the step of extracting, at the server, the partitions of coefficients set forth in the request comprises the step of obtaining the locations for the partitions of coefficients in the permanent storage medium; and

the step of transferring from the server to the client the partition of coefficients comprises the step of transferring the partition of coefficients from the permanent storage medium to the client.

12. The method as set forth in claim 9, further comprising the steps of:

receiving at the server, the request from the client to include at least one quantization value for at least one partition of coefficients;

quantizing, at the server, the partitions of coefficients, in accordance with the quantization value;

to generate quantized partitions of coefficients; and

compressing, at the server, the quantized partitions of coefficients to generate compressed partitions of coefficients.

13. The method as set forth in claim 9, wherein the source data comprises a source image.

14. The method as set forth in claim 13, wherein the source image comprises a medical image.