Removal of navigational lines from GMS images

Until recently grid and coast lines were superimposed on GMS analogue images at Japanese command and data acquisition stations before being broadcast to ground receiving stations. This paper describes a multi-stage method for line removal. An image is first preprocessed so that areas of high contrast are enhanced. A double adaptive thresholding technique is applied to locate pixels on lines. Line removal can be achieved by replacing each pixel on the lines by the average of pixels not on lines in the local neighbourhood. -from Authors