What is lossy compression?

What is lossy compression?

a) Image compression where the recovered image is different from the original.

b) Compression after which some portion of the original data cannot be recovered with decompression. Such compression is still useful because the human eye is more sensitive to some kinds of information than others, and therefore does not necessarily notice the difference between the original and the decompressed image.

c) Reducing the total data rate by discarding data that is not critical. Both the video and audio for DTV transmission will use lossy compression.