User Manual - pancroma

54. Image Processing Utilities – Grayscale and RGB________________________________________________________________PANCROMA TM provides image preprocessing techniques to improve the qualityof simple RGB band combinations. When bands 3, 2 and 1 are combined tocreate an RGB image, the result is very close to what the satellite sensor “sees”and theoretically no image processing is necessary. However atmospheric watervapor will scatter both incident and reflected light, especially in the blue band.The result can be a hazy image. Although this is a natural phenomenon, theappearance of RGB images can often be improved by the use of PANCROMA TMhaze reduction and contrast enhancement algorithms. These and all imageprocessing utilities are accessed using the Image Processing Data Input dialogbox, which in turn is presented when the ‘Activate Image Processing Routines’check box is checked on the main screen. The image processing routines canbe used during any image display routines, including the production of grayscale,RGB and pan sharpened images.The figure below shows the Image Processing Data Input box, with all the checkboxes checked. Not all of the image processing features apply to all operations.For example, the routines on the right side of the screen, in the ‘Pan SharpeningPost Processing Group’ apply only to the pan sharpening process. All of theroutines in the other data group boxes also apply to the pan sharpening process,but not the other way around. When you are processing a single grayscaleimage, for example, only one channel in the ‘Input Channel Adjust Group’ will beactive (as there is only one channel, namely the single grayscale band, toadjust.)IMPORTANT NOTE: PANCROMA TM will automatically enable and disable imageprocessing menu selections based on the operation that you are currentlyperforming. This is to prevent executing inappropriate image processing actions.For example, it would not make sense to adjust the three-color channels whenyou are processing a single image.154