IMAGE DIGITIZER SYSTEM-DESIGN CONSIDERATIONS

A 1024 multiplied by 1024 pixel image digitizer has been developed that provides high speed electrooptical scanning of image transparencies. The system consists of a linear diode array mounted on a stepping motor assembly to produce a 1024 multiplied by 1024 pixel array. An optical system projects image transparencies onto the detector at variable scales. One design utilizes a 5:1 zoom lens with 1. 0x and 2. 4x channels for selection of image sample spacing from 1. 3 to 16 mu m. Another optical design utilizes projection optics to enable sample spacing above 16 mu m. The design considerations applied to this type of instrument. are examined.