Picture enhancement by grey scale modification

Pictures were subjectively enhanced by adaptively modifying the gray scale rendition so that the occurrence of gray tones in each picture is approximately uniformly distributed over the available dynamic range. An infrared picture was photographed and the negative digitalized. A FORTRAN program was used to process the image data. A comparison was made between adaptive and nonadaptive image processing. Image sharpness was slightly reduced as a result of the compression of tone differences between adjacent points. A spatial filtering program was used to enhance the edges. The real time implementation of the technique using a microprocessor to enhance moving TV pictures is briefly considered.