So, water appears completely black. For the same reason, many of the dark smoke plumes are also blacked-out on the image. One of the easiest and effective forms of enhancement is histogram equalization . Histogram equalization distributes the display of gray levels evenly from dark to gray shades based on the actual distribution of gray shades in the image. The result is a product with a reasonably effective enhancement over all portions of the image.
Overlays can provide orientation and perspective.
The overlays presented below focus on different types of information. Geographic grids can be displayed at any desired latitude or longitude interval. The raw data in this image appear in satellite projection , meaning the way the data are originally scanned from the satellite, which is a function of satellite height, position and the angle at which the earth is viewed. However, it is not often the ideal way to view satellite images because of the distortions that are introduced. Notice how horizontally compressed the Red Sea is at the edge of the image.