How do libraries such as discutils/to interact with .PSD files work?

Question

Hi,

I see a lot of projects which involve some degree of reverse engineering (something I know very little about). For example, on codeproject there was an API to interact with .PSD files (Delete layers, add layers, add masking, etc) and there is also a discutils library for C# which interacts with .ISO files (not sure what the featureset of library is exactly).

I know that these sort of apps require reverse engineering to make, but where can I find more info of how these sort of programs are made (the code is open source and I will look at it, but I assume there are some guides on how to make programs like this)? Obviously this is more than just putting together C# methods.

Thanks

Answer 1

Gimp has partial support for managing PSD files. I would take a look at their implementation and start from there.