I maintain two directories:

• Working assets - Has textures/models/GUI graphics in their native format (Blender files, whatever gimp uses, etc.) This is not packaged into my game. Similar to how the source files are used to create the binaries, these files are used to create the resource files
• Assets - Has all the exported textures/models/graphics. These are all in formats that my game reads, they're the "final" format. Blender files are exported in to .x files with meshes and animations, art files are .png. These are packaged with the game.

When switching between my laptop and PC, I just check everything in, including what's in the working directories. Then I have the same tools on both computers, and I can just open the native formats with the appropriate tool and pick up where I left off. No problems.

I maintain two directories:

• Working assets - Has textures/models/GUI graphics in their native format (Blender files, whatever gimp uses, etc.) This is not packaged into my game. Similar to how the source files are used to create the binaries, these files are used to create the resource files
• Assets - Has all the exported textures/models/graphics. These are all in formats that my game reads, they're the "final" format. Blender files are exported in to .x files with meshes and animations, art files are .png. These are packaged with the game.

When switching between my laptop and PC, I just check everything in, including what's in the working directories. Then I have the same tools on both computers, and I can just open the native formats with the appropriate tool and pick up where I left off. No problems.

There are some repositories that have additional functionality, specifically for art. For example, github has Image view modes. Which has features like comparing images side by side, swipe (swipe a seperator across a single image to see "before and after"), onion skin (overlay a transparency of "before and after") and difference which shows just the differences.

Or TortoiseSVN shows images side by side.

The bottom line is, if you're hosting this repository yourself, you're going to need a lot of extra storage for graphics diffs. Because, like you said, it's not like a source code file where you only have to store the differential, you're likely going to end up storing multiple copies with only slight changes.