Kai's Power Tools Convolution Kernel Explorer, or KPT Convolver, from MetaTools (formerly HSC Software) is one of the first plug-in suites for Photoshop to go native for 32 bits. It seamlessly integrates into Photoshop 3.0.5. Convolver for Windows NT and Windows 95 provides a unified interactive approach for changing and correcting image details such as color, contrast, hue, saturation, sharpness, edges, and so forth. These visual effects taken together make up the convolution kernel (a mathematical 3D space), and with KPT's unique user interface (see screen A), you have complete control over editing and correcting these details, as well as creating new and different effects.

Is this program intuitive? That depends on you. If you are easily confused by a completely graphical representation of information, then you may have a problem. Otherwise, you'll get used to Convolver's automatic-highlight buttons, click-and-drag effects, and off-kilter menu system. If you've used other KPT products, you'll like the fact that Convolver works just like the rest of them.

Convolver offers three distinct operating modes that you can work in:

  • Explore, where you can randomly experiment with kernel mutations and effects
  • Design, which is a more structured way of working and provides a matrix of effects over which you have complete control
  • Tweak, for precise real-time control over image parameters (Tweak has three sub-modes: Linear Convolution, Gaussian/Unsharp, and Difference Mask.)

When you activate Convolver, it samples the entire image and gives you a smaller version to work on so you can see quick results. The preview mode can work either as a full-sized preview or as a grid of 15 variations. Each mode gives you varying degrees of control.

The Explore mode has three main controls:

  • Mutate Genes, which randomly generates combinations of effects
  • Genetic Diversity, which determines the intensity of the mutations
  • Gene Influences, which allows you to select which effects you'll use

The Design mode works like Explore but grants direct access to each effect, its intensity, and its interaction with other effects. In Design, you only get the grid/tile presentation, instead of the full preview, so you can see the results in varying degrees of intensity.

The Tweak mode allows you to get "down and dirty" with each effect and give the image that extra little "tweak" to make it perfect. You can fiddle with the edge angle, relief amount (for embossing), hue, tint, and others.

One interesting feature in Convolver is that it uses "stars," which are similar to the little gold stars you earned from your first-grade teacher. Stars are satisfying and annoying, in equal parts. You acquire them by using different parts of the filter in different ways. (I got two stars just playing around with it!) With each star, you get more access to functions within the program. Although I was unable to accurately determine what my extended access granted me, the dialog assured me that I had achieved something and now had new "expert" privileges. This may be a reasonably fun way to motivate you to try things, but I couldn't help but be irked that something was withheld from me at the start.

Convolver's documenta-tion is well-written and has plenty of diagrams in a "guided tour" format. If you enjoy just sitting and playing around with images, this application is worth the investment. Even if you don't want to play, it's still worth the money because Convolver contributes real value to the image-editing process.

KPT Convolver
System Requirements: Windows NT Workstation 3.51, 486 or higher, 16MB of RAM, 20MB Disk
MetaTools * 805-566-6200
Price: $199