Removal of navigational lines from GMS images
Binh Pham, Anthony John Maeder · Australian meteorological magazine · 1989
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. These lines must be removed before any global image processing operations can be applied to such an image. A typical method of using a median filter for removing lines does not produce useable results since the rest of the image is degraded during the filtering process. 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 the lines in the local neighbourhood.