This document describes a portable, battery-operated color video image capture system. In 1/30 second, the device (referred to as "PicturePerfect") can digitize a 640 x 400 pixel image in 16.7 million colors, acquiring both fields of an interlaced NTSC video frame.
An Integrated External Video Monitor, Digitizer, Frame Buffer, and Transmitter
A device was needed to serve in a capacity similar to a conventional Targa-style video capture board, but which would not require a connection to a host PC during the image capture process. It was necessary that the device be self-powered and portable. The device described here was designed and constructed to meet these criteria.
Known Prior Art:
Many video digitizer peripherals are available in the personal computer market. Better-known name brands include Targa, Vista, Oculus, and a host of others. None, however, offer the ability to acquire an image for later downloading to a separate host computer.
The Canon Xapshot(TM) camera contains an integrated camera and digitizer, but it also uses a proprietary floppy-disk drive for image storage, and does not directly transmit images to a host computer.
Description of Invention:
The PicturePerfect device contains three 8-bit analog-to-digital flash converters, six 256Kb by 4-bit video RAM banks, and circuitry to derive ADC and VRAM timing signals from the RGB camera's composite sync output. A shutter circuit triggers image acquisition from a front-panel button, and a unique I/O interface transmits the captured image data from the internal VRAM banks to an IBM-compatible personal computer's standard parallel printer port. The PicturePerfect adapter is self-contained and self-powered. Internal rechargeable batteries provide DC power to the camera, as well as to the adapter's own circuitry. Finally, a 4.5" monochrome pilot monitor is included to aid in image framing and focusing. (Refer to attached diagram.)
As stated previously, PicturePerfect's primary novel feature is its ability to operate as a "digital camera, frame buffer, and transmitter," functioning independently of a host computer.
PicturePerfect is invaluable for multimedia and entertainment applications in which there is a need to capture real-world images in environments where a conventional PC/Targa-style setup would prove awkward, inconvenient, or impractical. (Few video capture boards are small enough to fit in the expansion slots of laptop PC's.)