Wavelet Based Color Compression
description
Transcript of Wavelet Based Color Compression
![Page 1: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/1.jpg)
WAVELET BASED COLOR COMPRESSIONGreg Beranek
![Page 2: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/2.jpg)
BACKGROUND WDR
Significance Pass With threshold T and T2 find item where T2>Item>=T
Encode the Address Encode Plus or Minus
Repeat Refinement Pass
If Item >=T2 Write Refinement
Repeat
![Page 3: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/3.jpg)
WDR
![Page 4: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/4.jpg)
COLOR WDR Significance Pass
Three Passes Red Pass Green Pass Blue Pass
Refinement Three Passes
Red Green Blue
![Page 5: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/5.jpg)
COLOR WDR
![Page 6: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/6.jpg)
ISSUES COLOR WDR Progressive nature
Cannot stop anywhere (missing color component)
Speed 3 Passes 3 Scan orders 3 data matrices
Accounting
![Page 7: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/7.jpg)
RESOLUTION TO COLOR WDR ISSUES Color Correlation (lack of correlation)
Ability to predict significant values Encode more data with one color and get a very
close color when decoding Simplify scan order
![Page 8: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/8.jpg)
COLOR SPACE Primitive Color Spaces
RGB Additive color space Tells how much light is needed to make a specific color
CYM K Subtractive color space Tell what quantity of pigment is needed to make a
specific color Other Color Spaces
YUV YPbPr (YCbCr)
Video and Image Compression Schemes, Analog (Digital)
YCoCg Integer to Integer Color space similar to YPbPr
![Page 9: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/9.jpg)
TRANSFORM MATRIX RGB TO YCOCG Forward - RGB -> YCoCg
Reverse - YCoCg -> RGB
![Page 10: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/10.jpg)
BACK TO COLOR WDR We now have the ability to:
Predict significant color values
Simplify to one scan order
Retain some RGB color information when we stop encoding anywhere
![Page 11: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/11.jpg)
COLOR WDR
![Page 12: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/12.jpg)
OPTIMIZATIONS
Encoder optimizations
ASWDR
Lossy Color Space
![Page 13: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/13.jpg)
HOW GOOD IS THIS COMPARED TO JPEG 2000?
PSNR from Color Compression of Lena
1bpp (24:1) 0.5bpp (48:1)
JPEG2000 34.320604 32.239947
Color WDR 33.414003 31.180589
PSNR from Color Compression of Parrots (kodim23)
1bpp (24:1) 0.5bpp (48:1)
JPEG2000 40.553139 37.526301
Color WDR 38.60774 34.599361
PSNR from Color Compression of Hats (kodim03)
1bpp (24:1) 0.5bpp (48:1)
JPEG2000 39.946701 35.951137
Color WDR 34.542265 32.215072
![Page 14: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/14.jpg)
PICTURES LENA
Left : Original (Cropped)Top Right : Color WDR 1 bppBottom Right : JPEG 2000 1 bpp
![Page 15: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/15.jpg)
PICTURES HATS
Left : Original (Cropped)Top Right : Color WDR 1 bppBottom Right : JPEG 2000 1 bpp
![Page 16: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/16.jpg)
PICTURES PARROTS
Left : Original (Cropped)Top Right : Color WDR 1 bppBottom Right : JPEG 2000 1 bpp
![Page 17: Wavelet Based Color Compression](https://reader036.fdocuments.us/reader036/viewer/2022062410/56815a65550346895dc7ae66/html5/thumbnails/17.jpg)
QUESTIONS?