Image formats that support layers

Question

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 .bmp or .jpeg don't.

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.

Answer 1

TIFF can contain layers. This format should be supported by almost all image viewers.

Answer 2

In a practical sense, .psd (photoshop) is going to be the most portable format with the widest reach and most implementations, despite it not being "open".

Answer 3

You can try OpenRaster, which has some support by applications and is 100% open. For opening it, there is libora. Note that I never really tried it, I just know about it for some time. It's not so famous, but it's the only format I know which does not seem to be very specific to one application.

Answer 4

If you don't need raster support in the representation, but only in the resulting files, try SVG format with rendering down to whatever raster format when needed.

http://www.w3.org/Graphics/SVG/