Abstract: Apparatus and method for processing a raster scan video signal representing an image and detecting the outline of one or more objects in the image represented by the video signal. The steps of the method include encoding the raster scan video signal as a sequence of binary pixel values. For each of a plurality of the pixels the following steps are performed. It is detected when the binary pixel values representing the pixel and a horizontally adjacent pixel are distinct. It is also detected when both (a) the binary pixel values representing the pixel and a vertically adjacent pixel are distinct, and (b) the binary pixel values representing a pixel horizontally adjacent to said pixel and a pixel vertically adjacent thereto are distinct. The position of the pixel is reported when either of the detecting steps detects distinct binary pixel values. The second detecting step automatically eliminates redundant pixel reporting by eliminating the reporting of double diagonal pixels.

Abstract: Device and method for measuring the pitch of a musical sound and displaying the pitch and the pitch error. The device consists of analog signal processing circuitry and digital computing and display circuitry. The analog signal processing circuitry accepts a signal from an appropriate signal source, amplifies the signal if necessary, removes those frequency bands which are outside the area of interest, and generates a digital reference signal which represents zero-crossings of the analog signal. The digital computing circuitry performs an analysis using the zero-crossing time data and determines the fundamental pitch of the input signal. This is accomplished by, in effect, delaying the digital reference signal by successive amounts corresponding to the intervals between zero crossings, and correlating the effectively delayed signals with the digital reference signal. A high correlation corresponds to a delay which is near an integer number of periods.