This may not 100% help in your specific case, but in general this is how things are done in photoshop. I don't know about other programs, but most of this does apply to any program.

If you're enlarging an image- In the Image Size window make sure that "resample image" has been set to "nearest neighbor (preserve hard edges)" and then increase the pixel dimensions by an exact multiple. For example, 2x, 3x, 4x, etc. So something 50x50 could become 100x100 or 150x150 or 5000x5000, as long as it's an exact multiple.

To shrink an image you do the same thing, but divide it by an exact even amount. So 100x100 could be cut in half to be 50x50, or in quarters to be 25x25, but not in thirds because that wouldn't be an exact 33x33. If you shrink an image, unless it was already enlarged to begin with and you just divided it by the same amount it had been enlarged by, you're going to lose information/pixels. That means curved lines might not be very smooth, tiny details might be lost, etc. Dividing by a non-exact amount is possible, it just guarantees that you'll have some/worse rough lines and such afterwards. That's just how it is, but of course you can redraw and correct such things after shrinking it. Doing things this way will at least prevent the computer from making the image become fuzzy and adding unwanted colors.




Edited by tanuki - 18 May 2011 at 9:03pm

twitter may also automatically jpeg stuff, I know facebook does.

.png and .gif are the formats for pixelart btw :)


Edited by Jeremy - 20 May 2011 at 8:14pm