Method and apparatus for performing scalar quantization with a power of two step size

• US 7,095,900 B2
• Filed: 03/06/2001
• Issued: 08/22/2006
• Est. Priority Date: 02/15/2001
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Gormish, Michael J., Schwartz, Edward L., Boliek, Martin, Wu, Kok Gi
• Primary Examiner(s): Mancuso, Joseph
• Assistant Examiner(s): SHERALI, ISHRAT I
• Application Number:
  US09/800,530
• Publication Number:
  US 20030210827A1
• Time in Patent Office: 1,995 Days
• Field of Search: 382232-233, 382/240, 382244-251, 382/239, 375/240.03, 375/240.11, 375/240.16, 375/232, 37524018-24025, 35842601-42616, 341 50- 67, 341/105
• US Class Current: 382/251
• CPC Class Codes: G11B 27/036 Insert-editing
• CPC Class Codes: H04N 19/10 using adaptive coding
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• 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 19/129 Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO]
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/162 User input
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/34 Scalability techniques involving progressive bit-plane based encoding of the enhancement layer, e.g. fine granular scalability [FGS]
• CPC Class Codes: H04N 19/36 Scalability techniques involving formatting the layers as a function of picture distortion after decoding, e.g. signal-to-noise [SNR] scalability
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/426 : using memory downsizing methods
• CPC Class Codes: H04N 19/45 : performing compensation of the inverse transform mismatch, e.g. Inverse Discrete Cosine Transform [IDCT] mismatch
• CPC Class Codes: H04N 19/46 : Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/593 : involving spatial prediction techniques
• CPC Class Codes: H04N 19/61 : in combination with predictive coding
• CPC Class Codes: H04N 19/619 : the transform being operated outside the prediction loop
• 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 19/645 : by grouping of coefficients into blocks after the transform
• CPC Class Codes: H04N 19/647 : using significance based coding, e.g. Embedded Zerotrees of Wavelets [EZW] or Set Partitioning in Hierarchical Trees [SPIHT]
• CPC Class Codes: H04N 19/70 : characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/85 : using pre-processing or post-processing specially adapted for video compression
• CPC Class Codes: H04N 19/86 : involving reduction of coding artifacts, e.g. of blockiness

Abstract

A method and apparatus for performing scalar quantization with a power of two step size is described. In one embodiment, the method comprises receiving a sequence of image data to compress and specifying scalar quantization with a power of two step size using three bit values to apply to the sequence of image data.

Claims

1. A computer implemented method comprising:

receiving a sequence of image data to compress;

specifying scalar quantization with a power of two step size using only three bit values to represent a quantizer that is applied to the sequence of image data, three bit values specifying a number of magnitude wavelet transform coefficient bitplanes to be truncated during the quantization, each of the magnitude wavelet transform coefficient bitplanes representing a magnitude level associated with wavelet trandform coefficients, the three bits indicating that all bitplanes are to be truncated when the three bits are in predetermined logic states.

2. The method defined in claim 1 further comprising:

coding bitplanes specified for application of the scalar quantization.

3. The method defined in claim 2 wherein non-specified bit planes are not coded.

4. The method defined in claim 1 wherein all bitplanes are truncated during the quantization when each of the three bits representing the three bit values is a logical one.

5. The method defined in claim 1 wherein the three bit values specify 0, 1, 2, 3, 4, 5, 6, or all bit planes for truncation.

6. The method defined in claim 1 wherein specifying scalar quantization comprises specifying scalar quantization for individual frames of a motion video sequence.

7. The method defined in claim 6 wherein the video sequence comprises a motion JPEG 2000 Standard video sequence.

8. The method defined in claim 1 further comprising writing the three bit values to a controller to cause the controller to control compression hardware.

21. The method of claim 1, wherein a number of bitplanes to be truncated is greater than 7.

9. An apparatus comprising:

means for receiving a sequence of image data to compress;

means for specifying scalar quantization with a power of two step size using only three bit values to represent a quantizer that is applied to the sequence of image data, the three bit values specifying a number of magnitude wavelet transform coefficient bitplanes to be truncated during the quantization, each of the magnitude wavelet transform coefficients bitplanes representing a magnitude level associated with wavelet tranform coefficients, the three bits indicating that all bitplanes are to be truncated when the three bits are in predetermined logic states.

10. The apparatus defined in claim 9 further comprising means for coding bitplanes specified for application of the scalar quantization.

11. The apparatus defined in claim 9 wherein non-specified bit planes are not coded.

12. The apparatus defined in claim 9 wherein all bitplanes are truncated during the quantization when each of the three bits representing the three bit values has a logical value of one.

13. The apparatus defined in claim 9 wherein the three bit values specify 0, 1, 2, 3, 4, 5, 6, or all bit planes for truncation.

14. The apparatus defined in claim 9 wherein specifying scalar quantization comprises specifying scalar quantization for individual frames of a motion video sequence.

15. The apparatus defined in claim 14 wherein the video sequence comprises a motion JPEG 2000 Standard video sequence.

16. The apparatus defined in claim 9 further comprising writing the three bit values to a controller to cause the controller to control compression hardware.

18. The apparatus defined in claim 13 wherein the compressed data is compliant with the JPEG 2000 Standard.

22. The apparatus of claim 9, wherein a number of bitplanes to be truncated is greater than 7.

17. An apparatus for compressing image data comprising:

a controller to specify scalar quantization with a power of two step size using three bit values to be applied to the image data;

a compressor coupled to the controller to compress a sequence of image data to create compressed data, the compressor comprising a quantizer responsive to the scalar quantization specified by the controller to quantize the image data, the quantizer represented by only three bit valus, the three bit values specifying a number of magnitude wavelet transform coefficient bitplanes to be truncated during the quantization, each of the magnitude wavelet transform coefficient bitplanes representing a magnitude level associated with wavelet transform coefficients, the three bits indicating that all bitplanes are to be truncated when the three bits are in predetermined logic states.

19. The apparatus defined in claim 17 wherein the quantizer performs coding bitplanes specified for application of the scalar quantization.

23. The apparatus of claim 17, wherein a number of bitplanes to be truncated is greater than 7.

20. An article of manufacture comprising one or more computer recordable media having executable instructions stored thereon which, when executed by a computer, cause the computer to:

receive a sequence of image data to compress;

specify scalar quantization with a power of two step size using only three bit values to represent a quantizer that is applied to the sequence of image data, the three bit values specifying a number of magnitude wavelet transform coefficient bitplanes to be truncated during the quantization, each of the magnitude wavelet transform coefficient bitplanes representing a magnitude level associated with wavelet transform coefficients, the three bits indicating that all bitplanes are to be truncated when the three bits are in predetermined logic states.

24. The article of claim 20, wherein a number of bitplanes to be truncated is greater than 7.