The photograph that the images below were taken from, was snapped with a Casio QV7000-SX digital camera, in normal incandescent room lighting, with a camera flash. The .jpeg image was 1280 x 960 pixels, and had an initial filesize of 408K. A piece of that image was trimmed away, leaving just what you see to the right, at a width and height of 653 x 673 pixels. That image was saved as a .tif file before any further work was done on it. Just a section of that image was used for the demo below. Every time you re-save a .jpeg image, more data loss occurs.
Edges are sharper, colors are more solid.
Work with it as a .tif file, saving your changes periodically as a .tif file, then do your final save as a .jpeg before you put it on your website. Never save a .jpeg as a .gif file before you edit it. Gifs have a maximum of 256 colors, and .jpegs have a maximum of 16 million colors. See the examples below. The .jpeg above is still sharp and clear, saved at a quality level of 6.