Design Device
   by Tom DeWitt, 1975 (part 5 of 18)

expensive D to A and A to D converters and the eight bit wide memory system. The input through this cheap time base corrector will be a simple black or white j3ulse train which happens to be perfect for triggering a keying circuit.

The most common "special effect" available on commercial switchers is the geometric pattern called the wipe. The technique for generating wipes is quite straight forward and is used by Beck and others in artist oriented synthesizers. The pattern of the wipe is formed by the waveshape of an oscillator, and such wipes as diamonds, ellipsoids, and boxes are easily formed with an analog oscillator. The memory oscillator of the Design Device will permit virtually any shape of wipe to be made, and there will be provision for making multiples of any shape.

One of Steve Beck's contributions to video synthesis was a perceptive analysis of spatial composition. By dividing the image into components of point, line and volume he was able to design modules to achieve each objective. Among his inventions were devices that took complex imaqes and reduced them to these spatial elements. in many ways, this paring down of images is important because it allows the artist to simplify complex spaces and combine them inside a single frame. The Design Device will contain an outline generator which will reduce volumes to lines. This will permit many shapes to be seen through each other. Unlike Beck's outline generator, however, the Desiqn Device will be able to fill in horizontal lines. This technique was perfected by a commercial switcher manufacturer, Grass Valley Group, and involves an extra processing step which is very similar to the one bit time base correction.

The unique advantage of vector graphic systems like the RuttEtra synthesizer is its ability to reposition an image after it is recorded. Among the manipulations possible on such a system are electronic zooming, left-right inversion, top-bottom inversion and rotation. The Design Device will have processing modules which will permit all of the above effects. The rotation function is not normally available with commercially sold RuttEtra systems because it requires a low frequency sine-cosine generator. This pair of precisely timed control voltages will be available in the Design Device through its memory oscillators,.