Patent US6526174B1 successfully refreshed from Google Patents.
US6526174B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for video compression using block and wavelet techniques
Assignee: Apple Inc
•
Filing: 2000-02-28
•
Granted: 2003-02-25
•
Expires: 2020-02-28
Abstract
Abstract A method and apparatus are disclosed for symmetrically compressing and decompressing video information in real time by coupling block and wavelet techniques. In the compression pipeline, the image is divided into blocks comprising 2 k ×2 k pixels (in the preferred embodiment, k=1). The average color of each block is computed. The system computes an average luminance for each block and differential luminances of each pixel of the plurality of pixels of each block. A first plurality of frequency details of each block are determined by Haar transforming the differential luminances. The system computes an average color difference between each block and the preceding block, and quantizes the average color difference and the first plurality of frequency details using Lloyd-Max quantization. In an alternate embodiment, skip codes are generated for blocks having the same quantized average color difference and second plurality of frequency details. The quantized average color difference and a second plurality of frequency details are encoded using variable length codes. The system employs lookup tables to decompress the compressed image and to format output pixels. The output of the compression pipeline containing variable length codes is decoded into fixed-length codes, which are then decoded using a first lookup table into three device-independent components that represent each block. The three components index a second lookup table containing precomputed RGB values that include precomputed display dependent formatting to produce the output image. In the alternate embodiment, skip codes contained in the output of the variable length decoder are decoded.
Inventors
- 👤 Peter N. Graffagnino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:03
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/90; H04N19/10; H04N19/169; H04N19/186; H04N19/50; H04N19/593; H04N19/60; H04N19/63; H04N19/64; H04N19/645; H04N19/102; H04N19/124
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
142 words
A method for compressing an image of a first color space, wherein said image is divided into a plurality of blocks, comprising the steps of: computing an average color of a block of said plurality of blocks, said block comprising a plurality of pixels; computing an average luminance of said block dependent on said average color and a differential luminance of each pixel of said plurality of pixels of said block, wherein said differential luminance is the difference in luminance value between each particular luminance value of each said pixel of said plurality of pixels and a average luminance value of said block; and, encoding a quantized average color difference and a second plurality of frequency details of said block, wherein said second plurality of frequency details is less than or equal to a first plurality of frequency details of said block.
Claim 2
Independent Claim
142 words
A method for compressing an image of a first color space, wherein said image is divided into a plurality of blocks, comprising the steps of: computing an average color of a block of said plurality of blocks, said block comprising a plurality of pixels; computing an average luminance of said block dependent on said average color and a differential luminance of each pixel of said plurality of pixels of said block, wherein said differential luminance is the difference in luminance value between each particular luminance value of each said pixel of said plurality of pixels and a average luminance value of said block; and, encoding a quantized average color difference and a second plurality of frequency details of said block, wherein said second plurality of frequency details is less than or equal to a first plurality of frequency details of said block.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said plurality of pixels comprises 2 k ×2 k pixels.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein k is equal to one.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said first color space is a RGB color space.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein said first plurality of frequency details comprises an average term, a horizontal term, a vertical term, and a diagonal term.
Claim 7
Dependent Claim
20 words
The method of claim 5 wherein said second plurality of frequency details comprises said horizontal term and said vertical term.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein an average color difference and said first plurality of frequency details are quantized using a Lloyd-Max quantization.
Claim 9
Dependent Claim
20 words
The method of claim 7 wherein said Lloyd-Max quantization is dependent on a variance and a number of reconstruction levels.
Claim 10
Dependent Claim
24 words
The method of claim 1 wherein said quantized average color difference and said second plurality of frequency details are encoded using a Huffman coding.
Claim 11
Dependent Claim
34 words
The method of claim 1 further comprising the step of providing a skip code when said quantized average color difference and said second plurality of frequency details of said block matches a previous block.
Claim 12
Dependent Claim
20 words
The method of claim 10 wherein said skip code comprises an entry in a lookup table referencing said previous block.
Claim 13
Independent Claim
159 words
An apparatus for compressing an image, said image comprising a plurality of blocks, comprising the steps of: average color computation means for computing an average color of a block of said plurality of blocks, said block comprising a plurality of pixels; average and differential luminance computation means coupled to said average color computation means for computing an average luminance of said block dependent on said average color and a differential luminance of each pixel of said plurality of pixels of said block, wherein said differential luminance is the difference in luminance value between each particular luminance value of each said pixel of said plurality of pixels and a average luminance value of said block; and, encoding means for variable length encoding of a quantized average color difference and a second plurality of frequency details of said block, wherein said second plurality of frequency details is less than or equal to a first plurality of frequency details of said block.
Claim 14
Independent Claim
159 words
An apparatus for compressing an image, said image comprising a plurality of blocks, comprising the steps of: average color computation means for computing an average color of a block of said plurality of blocks, said block comprising a plurality of pixels; average and differential luminance computation means coupled to said average color computation means for computing an average luminance of said block dependent on said average color and a differential luminance of each pixel of said plurality of pixels of said block, wherein said differential luminance is the difference in luminance value between each particular luminance value of each said pixel of said plurality of pixels and a average luminance value of said block; and, encoding means for variable length encoding of a quantized average color difference and a second plurality of frequency details of said block, wherein said second plurality of frequency details is less than or equal to a first plurality of frequency details of said block.
Claim 15
Dependent Claim
16 words
The apparatus of claim 12 wherein said plurality of pixels comprises 2 k ×2 k pixels.
Claim 16
Dependent Claim
11 words
The apparatus of claim 12 wherein k is equal to one.
Claim 17
Dependent Claim
15 words
The apparatus of claim 12 wherein a first color space is a RGB color space.
Claim 18
Dependent Claim
26 words
The apparatus of claim 12 wherein said first plurality of frequency details comprises an average term, a horizontal term, a vertical term, and a diagonal term.
Claim 19
Dependent Claim
20 words
The apparatus of claim 16 wherein said second plurality of frequency details comprises said horizontal term and said vertical term.
Claim 20
Dependent Claim
14 words
The apparatus of claim 12 wherein a quantization means is a Lloyd-Max quantization means.
Claim 21
Dependent Claim
21 words
The apparatus of claim 18 wherein said Lloyd-Max quantization means is dependent on a variance and a number of reconstruction levels.
Claim 22
Dependent Claim
24 words
The apparatus of claim 12 wherein said quantized average color difference and said second plurality of frequency details are encoded using a Huffman coding.
Claim 23
Dependent Claim
42 words
The apparatus of claim 12 further comprising a skip code generation means coupled to a quantization means for generating a skip code when said quantized average color difference and said second plurality of frequency details of said block matches a previous block.
Claim 24
Dependent Claim
20 words
The method of claim 21 wherein said skip code comprises an entry in a lookup table referencing said previous block.
Claim 25
Independent Claim
157 words
A method for compressing an image of a first color space, comprising the steps of: dividing said image into a plurality of blocks in image space, wherein said blocks are comprised of a plurality of adjacent pixels in image space; computing an average color of a block of said plurality of blocks, said block comprising a plurality of pixels; computing an average luminance of said block dependent on said average color and a differential luminance of each pixel of said plurality of pixels of said block, wherein said differential luminance is the difference in luminance value between each particular luminance value of each said pixel of said plurality of pixels and a average luminance value of said block; and encoding a quantized average color difference and a second plurality of frequency details of said block, wherein said second plurality of frequency details is less than or equal to a first plurality of frequency details of said block.
Claim 26
Independent Claim
157 words
A method for compressing an image of a first color space, comprising the steps of: dividing said image into a plurality of blocks in image space, wherein said blocks are comprised of a plurality of adjacent pixels in image space; computing an average color of a block of said plurality of blocks, said block comprising a plurality of pixels; computing an average luminance of said block dependent on said average color and a differential luminance of each pixel of said plurality of pixels of said block, wherein said differential luminance is the difference in luminance value between each particular luminance value of each said pixel of said plurality of pixels and a average luminance value of said block; and encoding a quantized average color difference and a second plurality of frequency details of said block, wherein said second plurality of frequency details is less than or equal to a first plurality of frequency details of said block.
References Cited (Backward Citations)
US4454546A
Cited
US4706260A
Cited
US5047842A
Cited
US5416606A
Cited
US5341318A
Cited
US5196933A
Cited
US5333212A
Cited
US5303372A
Cited
US5297220A
Cited
US5341442A
Cited
US5796872A
Cited
US6330665B1
Cited
US5440345A
Cited
US5379355A
Cited
US5640159A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-02-24 | 2006-08-26 | 2007-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-02-24 | 2010-08-26 | 2011-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-02-24 | 2014-08-26 | 2015-02-25 | $7700.00 | Window Closed / Lapsed |