Compression of Stereo Images
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Transcript of Compression of Stereo Images
Basic AlgorithmDiscrete Cosine Transform
Uniform QuantizationNo Quantization Tables
Directly Store the DC Coefficients
Huffman Code the AC CoefficientsNo Run-Length Encoding
Zip the Final Binary Stream
Color CompressionAlgorithm A
Mode 0: Encode Cr, Cb Mode 1: Encode Cr, Cb + Cr Mode 2: Encode Cr, Cb – Cr
Algorithm A VariantMode 0: Encode Cb, Cr Mode 1: Encode Cb, Cr + Cb Mode 2: Encode Cb, Cr – CbPerforms Markedly Worse
Algorithm B• Estimate Cb, Cr based on Y
• Cb = acb Y + bcb
• Cr = acr Y + bcr
• For each block• Intra-mode• Code acb , acr , bcb , bcb
• For small blocks,• Too expensive
• For large blocks,• Too much MSE
Motion Compensation• Search for Nearest Match
• Make Decision Based on Lowest MSE
• Give Bonus to Certain Intervals to Cause Clustering of Motion Vectors
• Encode the Residuals Using DCT as Before
ConclusionHuffman Coding then Zip outperforms
Run-Length Encoding then Huffman Coding
Color Compression Using Algorithm A3 Modes of Operation {Cb, Cb+Cr, Cb-Cr}Provides slight gainsLimited by nature of Cb and Cr
Motion CompensationDid not prove beneficial