I am relatively new to the concept of layers in image editing software. If I understand correctly, some image/file formats such as Paint.NET's
.pdn or Photoshop's
.psd support layers, but others such as
I was wondering if anybody knows of an image file format that supports layers and that is relatively "open", in the sense that can be opened in different image editors (preferably lightweight and non-proprietary software) and for which read & write code libraries (e.g. in Python, C, C++, MATLAB) exist.