I'm just getting started in scrolling, but I've been doing computer graphics for print and projection for many years, using primarily CorelDraw and Corel Photo-Paint.
The bitmap formats (.BMP, .TIF, JPG, PNG, GIF, etc.) are all going to have "jaggies". I think .JPG is among the worst, because it's compression averages the values of pixels, so if you have an area where the color is similar, but not the same, JPG will make a blob of identical pixels. This can be ugly for type or other hard-edged areas. If you work with bitmaps, either use non-compressed formats like .BMP or .TIF, or compressed formats like .PNG or .GIF, which handle hard edges more gracefully.
I would think vector-based programs would be much better, as lines can be manipulated directly, though I've never been fond of the auto-trace feature of CorelDraw as you wind up with a bunch of little pieces of the image. The program can't understand what the image is and how it should be constructed. If I need to trace a bitmap, I usually put it on one layer and manually trace it on another. It can be tedious, but not as bad (IMHO) as piecing an auto-trace back together.
I have yet to try Inkscape, since I have CorelDraw, but may transition to it instead of paying to upgrading Corel, now that I'm retired.
Wally
