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What is JPEG?
-
"Joint Photographic Expert Group" -- an international standard in
1992.
- Works with colour and greyscale images, Many applications e.g.,
satellite, medical, ...
JPEG compression involves the following:
- Encoding (Fig 7.12)
JPEG Encoding
- Decoding - Reverse the order for encoding
The Major Steps in JPEG Coding involve:
- DCT
(Discrete Cosine Transformation)
- Quantization
- Zigzag Scan
- DPCM on DC component
- RLE on AC Components
- Entropy Coding
The DCT has already been introduced (Section 7.5.4) we now
summarise the other steps.
Dave Marshall
10/4/2001