Abstract: The invention relates to a system for sequentially analyzing each data point representing a digitized video line image and modifying the point to improve the quality of the image based upon an examination of surrounding data points. Specifically, data comprising a digitized scanned image with each point represented by a one bit digital signal is stored such that a matrix of data is continually supplied to a data multiplexer. The data multiplexer selects the portion of the matrix data to be compared to predetermined criteria to determine whether or not the data point being analyzed should be changed to improve the quality of the image.

Abstract: A system for magnifying a selected portion of a digital image as disclosed. The portion of the image to be magnified is selected and then each digital sample comprising the portion to be magnified is repeated in both the horizontal and the vertical direction to expand the selected portion of the image.

Abstract: A digital circuit for detecting changes in the gray scale of scanned images is disclosed. Each line of video information produced by scanning the image is digitized. Each digital sample is compared to digital samples delayed a predetermined amount to generate a difference signal which is indicative of a change in the gray scale having a component perpendicular to the direction of scan. The digitized samples of the video signal are also stored in a memory having a capacity sufficient to store data representing a plurality of scan lines with a typical memory having a capacity for storing digital information representing eight scan lines. Selected digital samples from the stored data are compared to samples of the line being scanned to detect changes in the gray scale having a component parallel to the direction of scan. These detected changes in the gray scale are combined to generate a signal which operates a printer to generate a line drawing of the scanned image.

Abstract: A device for substantially instantaneously converting a tonal image, such as a photograph, to a line drawing which depicts the lines formed by the borders of contrasting portions of the tonal image. The tonal image is scanned by a video scanner to produce a time varying video signal which signal is then differentiated to produce a signal consisting of pulses representative of predetermined selected levels of changes in tone, color, or shade. The signal is supplied to a pulse generator which produces a pulse of uniform width and height for each input pulse suitable for processing by a video receiver. The video receiver, being synchronized with the video scanner, is provided with means to instantaneously display a line drawing of the tonal image. Circuit control means are also provided to vary the uniform width of the lines in the resulting line drawing and to control the selection of lines in the line drawing in accordance with its corresponding significance in the tonal image.