Extra low-level information about PNG file

Could you please tell where I 开发者_如何学Ccan find information about the low-level distinctions in saving PNG files in different editors, the ways to hide extra information inside them (e.g. steganography) and other such stuff connected with PNG. Thank you.

The facilities available are those detailed in the standard for PNG and the approved code modules for the file content which may involve using a container-file principle. The law for PNG also has precedence and content and storage are subject to the laws of England and other countries. PNG can mean postfix notational graphic or posterise normalised graphical or similar terms. In America their law has different words for the term PNG and the files are a different format.