Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have just learned that PNG is a lossless image format while BMP can be both uncompressed or lossless format. Should there be a quality difference between these two? If not, does it mean that other lossless formats like TIFF, JPEG2000 and PNG offer the same quality as BMP?

share|improve this question
JPEG2000 is not always lossless. You can use it lossless, but mostly, it's used to compress images in a lossy way. – slhck Feb 4 '12 at 22:10
up vote 9 down vote accepted

BMP is both uncompressed and lossless. PNG is compressed but lossless. Thus, with a lossless format the only visible difference is the file size. I'd recommend using PNG over BMP unless you can't for compatibility reasons.

share|improve this answer
You said visible difference. Should there really be any difference except for file size? – user1032421 Feb 4 '12 at 22:13
That is correct. The pixels will be 1:1. – iglvzx Feb 4 '12 at 22:15
PNG also supports transparency while BMP doesn't. – dnbrv Feb 5 '12 at 4:05
BMP does support alpha channel (transparency) since Windows 95. Just that Paint in Windows does not save the file with transparency (for compatibility reason?), which I think might have been the source of misconception. – nhahtdh Apr 6 '13 at 21:59

There's no quality difference between BMP & PNG format (except PNG is compressed using deflate algorithm).

BMP8 can be compressed using RLE (run-length-encoding) algorithm, but BMP16/24/32/64 doesn't support compression yet.

BMP32 support alpha channel just like PNG32 support transparency.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.