Alien Skin Software has earned a reputation for developing stellar -- if somewhat wacky -- image-editing plug-ins that can add effects such as fire and smoke to photographs. But with the release of Image Doctor, an impressive new set of four filters, the company proves that its software can just as skillfully remove blemishes, unwanted background elements, compression artifacts, and other undesirable details.

The first three Image Doctor filters let you quickly remove unsightly elements from an image by using samples from the surrounding textures and colors to fill in the problem area. The concept is reminiscent of Photoshop 7's Patch tool, and the results are often comparable. But Image Doctor distinguishes itself by offering a well-designed interface, a large preview window, and useful sliders and options for added flexibility and control over the resampling process.

Impressively, the filters almost always eliminated the target flaw on the first try. However, you'll need to divide large selections into small segments for individual filtering to get the best results and to avoid slowing Image Doctor's performance to a crawl.

Web designers who have the unfortunate task of repurposing a highly com- pressed JPEG file when the original is no longer available may find Image Doctor's JPEG Repair filter useful. It smooths out the blocky, patchwork appearance of compression artifacts while adding grain to keep the image from appearing overly cartoonish.

While Image Doctor's other filters typically hit their marks, JPEG Repair's effectiveness varied, proving most useful in images without a lot of fine detail. (For best results, use selections to apply varying levels of repair to different parts of the image.) But in a pinch, JPEG Repair can be a beneficial tool, and it consolidates into one convenient window a pro-cess that usually requires the tedious application of several Photoshop filters.

Macworld's Buying Advice

If you have yet to upgrade to the latest version of Photoshop -- or if you have another image editor -- Image Doctor is a must-have filter set. Its simple interface and intelligent sampling make removing flaws a piece of cake. And although most Photoshop 7 users will likely be satisfied with that program's built-in Patch tool, those who spend a lot of time restoring or touching up photos may find Image Doctor's added flexibility worth the extra money.