As it is, sprite animation frames are compiled on export into optimized sprite sheets which is great for saving video memory. It's very nice to be able to import individual frames and just let C2 handle the arranging into sprite sheets later. But graphics change and revisions tend to get made to sprites during development. This can range from simple color tweaks to complete replacements of sprite gfx.
You might for instance want to create a character B that shares most behaviours/animations with character A but has a different visual look, so you copy the sprite with animations and all and replace the graphics while keeping width/height and image points for the animation itself. Or you're just not happy with the colors you've used for character A's sprite and want to tweak them a bit. In those cases, it can get very time-consuming and tedious to go through all the animations in the image editor and delete-copy-paste sprite frames one-by-one, especially when you have frames in the hundreds or even more!
If we had a way to compile sprite sheets in the editor and then access those sprite sheets directly from within the editor, large-scale changes to graphics could be made in no time at all compared to changing every frame individually. Need to tweak colors? Okay, just copy the entire sprite sheet from C2 into your graphics package of choice, make the color adjustments and paste it back into C2. Same with updating/replacing sprite frames, it would be a bit more work than just color/contrast-type tweaks of course but being able to access entire sprite sheets at a time would still be *way* faster than changing each frame separately.
I created a couple of mock-ups below to illustrate what I mean. I imagined the editor to reference the sprite sheet internally if one exists and just do what it does now if a sprite sheet hasn't been compiled yet.
Image Editor - Regular view:
Image Editor: Sprite Sheet view:
I understand this could mean a pretty major re-working of how the C2 editor works internally when it comes to sprite arrangement and the whatnot, but it would be a great time-saver for artists who need to make cosmetic sprite changes to entire sets of animation frames.