One User's Opinion

© 2000 by Foster Coburn. All Rights Reserved.

If computers are so darned smart, why can't you open an image and have the person in the picture cut out perfectly every time? It sure is obvious to the human eye that there is a person standing there. And we can certainly distinguish what part is flowing hair and what part is background. You've tried to do this with the magic wand tool in your favorite image editor and the results are horrible at best. Using the Extract functions in Photoshop comes close, but it still isn't perfect. And if we are dealing with transparent images like glass objects, fuhgedaboutit!

So I took a close look at Corel KnockOut 1.5, a tool for cutting out images that can't easily be cut out elsewhere. You might remember this product as Ultimatte KnockOut as Corel purchased the distribution rights last fall. Ultimatte started as a company that creates special effects technology for the motion picture industry and KnockOut is a by-product of their Oscar-winning blue screen technology. Since Corel has purchased the product, they have ported it to Windows and added support for Photoshop and Corel PHOTO-PAINT file formats. And even more important, they've lowered the price to a suggested retail of $280 US down from the $499 and up that Ultimatte charged.

Yes Virginia, There is a Magic Wand

The real magic done by KnockOut is based on the "transition area". You draw a "mask" just outside of the object you want to isolate. Then draw another "mask" just inside of the object and push the Process button. For many images, it is really that easy to get the perfect mask. At right is an image showing the two masks before we have processed. Below is the resulting image against a solid background. Total time to do this was only two minutes and that was without reading the manual!

Now I'll admit that this example was fairly simple. But keep in mind the background was a light gray and so was an awful lot of the bear's fur. So let's try something just a tad more difficult. How about a light bulb? It should have most of the bulb transparent so that we can see through to the background of the image. Though some of the image must be opaque so that you can see it is a light bulb. So again I defined the inside and outside masks. But I also pinpointed opaque areas of the bulb itself and along the filament. And to make the example even more impressive, I used the shadow masking tools to capture the cast shadow as well. In the image below, you'll see the masks I created on the left and the resulting image against a blue background on the right. Total time to create this was under five minutes. Try doing this with only Photoshop or PHOTO-PAINT!

As KnockOut is a masking tool, it has many of the same features you'll find in your favorite image editor. Once a mask has been drawn, you can hold down the Shift key and Alt keys (Command on the Mac) to add or subtract from the mask. The tool I found the most useful was the Loupe Zoom, activated by pressing the L key on the keyboard. As you move your cursor, it shows a magnified view that moves with you as shown at right. You'll find that almost every command or tool in the program has a shortcut key. This can be especially handy when you toggle between views to see if you need to tweak your mask further.

For images that are really tough, there are a couple of other handy tools. With the syringe, you can restore foreground detail that was lost in processing. It's just a matter of clicking on the color that is being lost. And there are times that the resulting edges aren't as smooth as you like. The Edge Feather can be used to smooth out those edges with fantastic results.

Is KnockOut Really This Good?

There are similar tools to KnockOut that work as Photoshop plug-ins. KnockOut is actually a stand-alone program. After you've masked an image it can be saved as a TIF with alpha channel, a Photoshop PSD file or as Corel PHOTO-PAINT CPT file. It would be nice to have KnockOut available as a plug-in, but it really isn't a problem to save the file from KnockOut and import into your favorite image editor. The only possible downside would be making sure you have enough memory to handle both applications open at once as well as the images themselves. And you've gotta believe that Corel will find some way to make KnockOut work more closely with PHOTO-PAINT.

In previous reviews I've been pretty tough on products that don't provide documentation. That won't be the case with KnockOut. On the CD is an excellent 20-minute QuickTime tutorial that gives you detailed examples of how to effectively mask several types of images. I didn't even crack the printed manual until I'd successfully masked a few images. And there is a very good printed color manual for both the Mac and Windows versions in the box. So no matter your platform, you're covered. Lastly, there is online help for those who want instructions on screen.

If you are an image editing professional who needs to create complex masks, you need KnockOut. Within a very short time you can master the toolset and mask images that would either be impossible or, at the very least, time consuming in any other software. Even with Corel's price drop, it is pricey for a one-trick pony. But don't let the price scare you away as it will easily pay for itself as your productivity soars.

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Foster D. Coburn III has written six best-selling books on graphics software and is currently the Webmaster of the popular Graphics Unleashed Web site.

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