This proposal describes a new kind of video synthesizer which uses the graphic potential of the video medium for a programming language. The instrument, called the Design Device, will perform video synthesis and signal processing unde-control from a mini computer which reads a specially formatted picture language. This programming language will permit artists to prepare ideas away from the studio and provide a permanent record on paper of all useful programs.

Review of Existing Video Synthesizers and Ideas for a New One

To free the video artist from the confines of the real camera-recorded world, it is necessary to develop instruments which generate a television compatible signal from raw electronics. A synthesizer is the paint and palette of the video artist, a device which lets the artist construct spaces from the dictates of imagination.

The first video synthesizers began- to appear almost a decade after the development of complete audio synthesis systems. There are compelling reasons for this delay. The development of a time variant artform is just now being born in the visual arts, centuries after the establishment of a related set of time variant structures in music. Technically, the video synthesizer is more complex than its audio cousin. Video signals cover a frequency spectrum 100 times greater than audio and must be constructed according to a precise timing synchronization which does not exist in the one dimensional audio signal. Consequently, design concepts and instrument components are now coming together for the first time.

There have been two approaches to video synthesizer design, vector graphics and signal intensity. This split is a consequence of the television system itself which uses a one dimensional high frequency signal to describe a two dimensional field of much lower frequency. The systems developed by Steve Rutt and Bill Etra, Computer Image Corp., Vector General, and others operate on the x and y deflection amplifiers of a cathode ray display. The synthesized or processed images coming from these devices are rescanned by a conventional camera for recording on video tape. Digital signal synthesizers, on the other hand, such as those developed by Steven Beck, Dan Sandin, and EMS Ltd., operate on the intensity or-"z" component of the video signal. Their output is made compatible with video standards by processing in a color encoder. The two approaches can be combined in a single device. In fact, Sandin has worked extensively with a computer controlled vector display, and RuttEtra synthesizers are invariably teamed with keyers, colorizers and other signal processors. However, no one has come out with an integrated package that incorporates both approaches. The Design Device will attempt this marriage of design principles.