User Manual - pancroma

The panchromatic image is the one in the form named ‘RGB Form’ and thecomparison image is in the form named ‘RGB Comparison Form’. TheHistogram Form shows the results of the histogram match algorithm. This utilityadjusts the panchromatic band pixels to match more closely the radiance of theideal computed Intensity band. The default condition is for the first channel of thehistogram to be ignored when making the computation in order to avoid skewingthe result if there are may black pixels in the image collar. Since this subsetdoes not include the collar, it is more accurate to include the zero channel.Now let us compare the two images and see if we need any adjustments. Thefirst thing we notice is that the panchromatic image is twice as big as thereference image. Of course this is the whole point of the panchromatic process.Looking at the color fidelity, we notice that in some respects the panchromaticimage is perhaps better than the reference image. The clouds are less washedout, there is more green in the land mass (reflecting vegetation) and the image isless hazy. I decided that I liked these features.Other images may not be so cooperative and require adjustment of all theseaspects. However, notice that the ocean is a different color in the panchromaticimage. It is very dark and not as blue. This is a very common artifact of the HSI314