Image compression

Question 1

Explain the principle of run-length coding.

Answer 1

Consider the following sequence of numbers (e.g. representing pixel values):
212 211 211 215 214 214 214 214
To reduce the size of this, we specify how many times the following value repeats.

before:
212 211 211 215 214 214 214 214
after:
1212 2211 1215 4214
Useful for sparse data with adjacent identical values.