Curtain is a video edge processor designed for sharpening, blurring, and outline extraction. Comprised of a wideband voltage controlled filter and multiplier, it is similar to tools used for X-Ray analysis in the era of analog graphics. Curtain is equally useful for processing video images as it is for adding dimensionality and contours to shapes and patterns.
Voltage controlled filter with 1:100 continuous tuning ratio allows a full sweep from thin to wide time constants. Three range settings cover a cutoff range from 100Hz to 5MHz.
Switchable rectifier allows selection of positive rising edges and falling negative edges, both edges positive, rising edge only, or falling edge only.
Voltage controlled depth allows a continuous sweep of filter output amplitude and inversion. This enables settings from blur to sharpen on a single modulation channel.
Separate inputs for the filter and output mix allow edge processing from once source and output mixing with another. Dedicated filter and mix outputs allow further external processing.
All signal and control paths perform at high frequency, video rate modulation speeds.
AC/DC input coupling switches and inverting level attenuators on voltage control inputs.