Back to Removing the Background

Formerly known as Ultimatte KnockOut, this product was once only available for the Macintosh platform. It was recently purchased by Corel and ported to the Windows platform. It's a standalone product that offers superior masking capabilities in a surprisingly simple interface.

KnockOut's tool palette is shown here. In addition to this tool palette, there is a palette for showing and hiding the various selection indicators, and a palette for changing the underlay color after your background has been knocked out. The four tutorials included with the software are very effective in getting you up and running quickly.

You prepare an image for processing by first drawing a selection marquee for the inside of your object, and another marquee for the outside of your object. For simpler images, you can stop there and process the image. Otherwise, you can use the shadow selection tools, the syringe tools, and the feather tools to refine your selections. You can continually switch between the original and the "knocked out" image as you refine your selections. At any time, you can process the image to see the results of your changes and go back to make additional adjustments as neccessary. You can also adjust the transition complexity to further refine how images are processed.

In my experience, I found that I was quite impressed after working through the images provided with the tutorials; however, when working with real-life images it was a bit more of a challenge to get good results. The bottom line, I think, is that complex extractions are always going to be complex, no matter what tool you use to extract them. Obviously, the more practice you have with any tool, the better results you're going to get, and this tool is no exception. Nonetheless, KnockOut has a relatively short learning curve. Even with a bit of struggling to grasp the concept of the syringe tools, I was able to get a feel for how the software worked in just a few sessions.

My biggest complaint about KnockOut is that it still requires you to make a fairly precise selection... and not just one selection, you have to make two selections... inside and outside. If you don't have a steady hand in the first place, it can be tedious work. Another nuisance is the zoom control limitations. I found it very restricting to only be able to zoom at specific set intervals (25%, 50%, 100%, 200%, 400%, etc.) On the other hand, the area where KnockOut really shines -- and you'll see this in my examples -- is with images that have wispy strands of windblown hair, and objects with partial transparency along the edges.

KnockOut can open the following image types: UKO (KnockOut's own image format), Bitmaps (BMP, JPEG, JPG, and TIFF), Photoshop PSD files, and Corel Photo-Paint CPT files. Projects in progress can be saved to KnockOut's UKO format and all selections will be retained. Once you've processed the image, it can be exported along with its alpha channel mask to TIFF, PSD, or CPT format. The image can then be opened in any editor that supports these formats with embedded alpha channels.

Example Results: 1 2 3 4 5
New: KnockOut 2

Some images from Nova Development's Art Explosion 600,000.