Multimedia Computing · Unit 3
Data Compression Techniques
Exam-focused notes for Data Compression Techniques (Multimedia Computing, BIT356): what the TU syllabus asks and how it has actually been tested, with 3 solved past questions from this unit.
What this unit covers
- Data compression definition and necessity
- Lossy compression methods
- Lossless compression methods
- Huffman coding algorithm
- DCT compression mode
- Expanded lossy DCT mode
- Compression mechanism comparison
Data compression definition and necessity
Why is data compression needed? How is lossy compression different from lossless compression? [5]
Data compression is needed for the following reasons: 1. Storage Space Reduction: Compressed data requires significantly less disk or memory space, allowing more data to be stored on the same physical medium. 2. Faster Data Transmission: Smaller file sizes ...
Full solved answer →Expanded lossy DCT mode
What is data compression? How working mechanism of lossy DCT mode is different from expanded lossy DCT mode of data compression?[10]
Data compression is a technique used to reduce the size of data files by removing redundancy and unnecessary information. It involves encoding information using fewer bits than the original representation, thereby reducing storage space and transmission ban...
Full solved answer →Huffman coding algorithm
Let A = {a/20, b/15, c/5, d/15, e/45} be the alphabet and its frequency distribution. Now show how Huffman Coding works. Make your assumptions if required. [5]
Alphabet with frequencies: Symbol Frequency ------------------- a 20 b 15 c 5 d 15 e 45 Total frequency $= 20 + 15 + 5 + 15 + 45 = 100$ - Binary Huffman tree; left branch = 0, right branch = 1. - When combining, pick the two nodes with the smallest frequenc...
Full solved answer →Make Unit 3 stick
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