Differentiator

High-pass filtering, edge extraction and enhancement

This module is a video rate high pass filter with six inputs, each representing different cutoffs. This module can be used for edge extraction or enhancement, or as an alternative way of mixing signals. Inputs can be unipolar or bipolar. Output is bipolar.

differentiator is an edge extraction tool which produces an output which is proportional to the rate of change of the input video signal. fast rates of change correspond to edges in a picture and are preferentially amplified by the module. the first (top) input jack amplifies only the sharpest edges. the second amplifies the sharpest edges and slightly softer edges. the following three inputs amplify progressively softer and softer edges until by the sixth input almost all of the video signal is amplified.

the two outputs are bipolar (signal range from -1v to 1v). from the first output, rising edges correspond to positive output peaks and falling edges correspond to negative output peaks. from the second output, this relationship is inverted.

differentiator is a circuit found in the classic sandin image processor designed and built in the 1970's by dan sandin at the university of chicago. it has been adapted for use with the lzx visionary video synthesis system by lzx industries. we are offering this module in fully assembled and also a full kit format for users who would like to assemble the module themselves.