Abstract: An NTSC composite color video signal is dematrixed and its RGB components are digitized so that each image or input frame is represented by a 512.times.512 pixel array. One high resolution output field is generated for each input frame by deriving a plurality of subpixel values for each input pixel. The subpixel values for a given pixel are derived by examining the nearest neighboring pixels and by utilizing enhancement algorithms represented by data in lookup tables. Signal to noise ratio improvement is achieved by comparing each given pixel value to the values of its neighboring pixels and then deciding whether or not to keep the given pixel value or to replace it with the median of it and its nearest neighbors. The subpixel values are fed through a digital to analog converter where the appropriate synchronization is added so that the analog outputs of the three branches of the device conform to the RS 343A format.