Converting JPG to PNG reverses lossy compression, saving the current state as lossless. This matters when you plan to edit further—each JPG re-save applies more DCT compression and degrades quality. PNG preserves what you have, though it can't restore detail already lost in the original JPG. The Canvas API reads the JPG bitmap into memory, then exports it as PNG without additional compression. Useful for graphics that need transparency (though the JPG background becomes solid) or iterative editing without generational loss.