Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!


Welcome to the new platform of Programmer's Heaven! We apologize for the inconvenience caused, if you visited us from a broken link of the previous version. The main reason to move to a new platform is to provide more effective and collaborative experience to you all. Please feel free to experience the new platform and use its exciting features. Contact us for any issue that you need to get clarified. We are more than happy to help you.

PNG Format


We are trying to build a PNG Encoder. We have problems understanding how is the IDAT chunk built. We understand that the first 4 bytes are the length,the second 4 bytes are the IDAT signature, then raw data and of course 4 bytes of CRC at the end. Our problem is that the first 7 bytes in the data do not represent pixel indexing, but something else, and we can't figure out what. Any ideas what those bytes might represent?

Any help would be appreciated

Thank You,


Sign In or Register to comment.