How would I write a Photoshop plugin for an image format?

Question

I have an image format and Photoshop doesn't support it. I've been tasked with writing a plugin to import or open the format, but there seems to be little information out there and what information I can find is all about writing filters. However, I want to import/export/open, not filter it.

Answer 1

My experience with photoshop import filters is roughly six years old, so take this comment with a grain of (old) salt.

I just took the import filter example code from the official SDK as a boilerplate and added my own decoding function. It was a straight forward job and took a week from start to finish.

If I remember right the worst thing was:

1. Getting the compiler settings right and compile the example code (two days)

2. Learning how the Photoshop GUI works. It was not standard win32 back then but something half mac resource based. I think they've changed that though.