Reduced error processing of transformed digital data

• US 7,724,976 B2
• Filed: 03/08/2007
• Issued: 05/25/2010
• Est. Priority Date: 11/04/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mitchell, Joan LaVerne, Bright, Martin James
• Primary Examiner(s): SHERALI, ISHRAT I
• Application Number:
  US11/683,494
• Publication Number:
  US 20070160146A1
• Time in Patent Office: 1,174 Days
• Field of Search: 382232-348, 382250-253, 3484001-4201, 3754201-24026, 708203-209, 708400-405, 35842601-42616
• US Class Current: 382/248
• 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 19/60 using transform coding
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets

Abstract

This invention solves problems due to employing error degraded data in digital processing. It particularly solves multi-generation problems wherein transform data degrade during each inverse transform and forward transform cycle even without any processing due to the rounding and clipping errors. It provides methods, systems and devices for reduced-error processing of transform-coded data. After inverse transformation of transform data, high-precision numbers are manipulated. The converting to integers and clipping to an allowed range steps are executed at any stage in the manipulation to obtain integer representation of the inverse transformed data such as for displaying of the data. However, further processing including forward transforming back to the transform domain is executed on the high-precision numbers. Thus, the rounding and clipping errors are not present in the processed data. Although advantageous to many applications employing digital transformed data, the invention is particularly advantageous for use in digital studios during editing of MPEG-coded, JPEG-coded and wavelet-coded video and audio data.

Claims

1. A method for digitally processing transform data, the method comprising:

using an inverse transformer device for performing an inverse transform of said transform data representing a phenomenon to the real domain forming high-precision data, said phenomenon comprising at least one selected from a group consisting of;

a spectral analysis, a spectrum analysis, an image, electromagnetic environment data, an audio clip, and a video clip; and

using an input for receiving the high-precision data that has been manipulated to produce an effect on the phenomenon;

using an integer converter for performing a forward transform of the manipulated high-precision data to produce integer real-domain data; and

using a clipper for clipping the integer real-domain data to within an allowed range to produce the integer real-domain data in the allowed range.

2. A method as recited in claim 1, wherein the inverse to said forward transform is different from said inverse transform.

3. A method as recited in claim 2, wherein said forward transform is a forward discrete cosine transform and said inverse transform is an inverse discrete wavelet transform.

4. A method as recited in claim 1, further comprising manipulating said the integer real-domain data high precision numbers to produce an effect.

5. A method for digitally processing transform-coded data, the method comprising:

using an inverse quantizer device for performing an inverse quantization of the transform-coded data, representing a phenomenon comprising at least one selected from a group consisting of;

a spectral analysis, a spectrum analysis, electromagnetic environment data, an image, an audio clip, and a video clip, to provide transform data;

using an inverse transformer device for performing an inverse transform of said transform data to the real domain forming high-precision data;

using an input for receiving the high-precision data that has been manipulated to produce an effect on the phenomenon;

using an integer converter for performing a forward transform of the manipulated high-precision data forming forward transformed data; and

using a quantizer for performing a quantization of said forward transformed data forming quantized data.

6. A method as recited in claim 5, further comprising:

entropy decoding coded data forming transform-coded data employing entropy decode; and

entropy encoding the quantized data employing entropy encode forming encoded data.

7. A method as recited in claim 5, further comprising manipulating the quantized data to produce an effect.

8. A method as recited in claim 5, further comprising converting said high-precision data to integers and clipping to an allowed range forming converted data.

9. A method as recited in claim 7, further comprising

alternating manipulating steps with the steps of

performing a forward transform,

performing a quantization,

entropy encoding,

entropy decoding,

performing an inverse quantization, and

performing an inverse transform a desired number of times.

10. A method as recited in claim 9, wherein said coded data are compressed data, and each step of alternating implements a compression/decompression cycle.

11. A system employing the method recited in claim 9, wherein each step of alternating recompresses and decompresses coded data to enable an editing operation.

12. A method as recited in claim 6, wherein said coded data are coded audio data.

13. A method as recited in claim 6, wherein said coded data are coded electromagnetic environment data.

14. A method as recited in claim 6, wherein said coded data are coded video data.

15. A method as recited in claim 6, wherein said coded data is encoded in the JPEG standard format.

16. A computer readable storage medium having computer program code embodied therein for digitally processing transform data in the real domain representing a phenomenon, the computer program code causing a computer to effect:

performing an inverse transform of said transform data to the real domain forming high-precision data, said phenomenon comprising at least one selected from a group consisting of;

a spectral analysis, a spectrum analysis, an image, electromagnetic environment data, an audio clip, and a video clip; and

receiving the high-precision data manipulated to produce an effect on the phenomenon;

using an integer converter for performing a forward transform of the manipulated high-precision data to produce integer real-domain data; and

using a clipper for clipping the integer real-domain data to within an allowed range to produce the integer real-domain data in the allowed range.

17. The computer readable medium as recited in claim 16, wherein the inverse to said forward transform is different from said inverse transform.

18. The computer readable medium as recited in claim 16, wherein said forward transform is a forward discrete cosine transform and said inverse transform is an inverse discrete wavelet transform.