Run Length Encoding & Dictionary Coding (OCR A-Level Computer Science): Quizzes
📚Quizzes
Practise the questions
12 questions from this quiz
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Practise the questions
12 questions from this quiz
What is the main purpose of compression?
What is the main purpose of compression?
To reduce the size of data files
How does Run-Length Encoding store repeated data?
How does Run-Length Encoding store repeated data?
As a single value and a count
What is the RLE compressed version of AAABBBBCCCCCDDD?
What is the RLE compressed version of AAABBBBCCCCCDDD?
3A4B5C3D
When is RLE ineffective for compression?
When is RLE ineffective for compression?
When data has few repeating values
Which type of data is RLE most effective for?
Which type of data is RLE most effective for?
Simple images with uniform colours
What does Dictionary Coding replace in data?
What does Dictionary Coding replace in data?
Repeated patterns with shorter codes
What is the first step in Dictionary Coding?
What is the first step in Dictionary Coding?
Analyse data to identify patterns
Which compression formats use Dictionary Coding?
Which compression formats use Dictionary Coding?
ZIP and LZW
What is a main drawback of Dictionary Coding?
What is a main drawback of Dictionary Coding?
Memory overhead from storing dictionary
Which compression needs an additional data structure?
Which compression needs an additional data structure?
Dictionary Coding needs a dictionary
Which compression is recommended for simple monochrome bitmaps?
Which compression is recommended for simple monochrome bitmaps?
Run-Length Encoding
Which compression is best for high-resolution photographs?
Which compression is best for high-resolution photographs?
Neither RLE nor Dictionary Coding