PNG files structure

Question

I've already learned how to generate BMP images based on the BMP files structure (here and here).

Now I'm looking for the PNG file structure but I haven't found any good explanations.

Do you know where I can find this explanation with schemes as well?

Answer 1

The complete specification is available here: http://www.libpng.org/pub/png/spec/1.2/png-1.2.pdf

Note that the PNG format is much more complex than BMP, since it allows compression, etc.

Answer 2

What about Wikipedia's explanation? It seems to be written very well and is very easy to understand. There's also the specification, which goes into everything.