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One of the inherent advantages of soft copy viewing is the ability to manipulate an image in the spatial and tonal domains. With a hard copy, DR is restricted to the density range of the film or paper used. The tone (or color) displayed on the image is proportional to the light energy distribution in the scene and the characteristics of the capture and display devices (e.g., exposure, gamma, DR). In the soft-copy environment, the range of tones or colors can be manipulated in real time to enhance specific portions of the DR. Further, a variety of enhancement operations in the spatial domain can be applied. This chapter reviews and demonstrates the effects of various pixel processing operations by defining the order in which they should be applied for maximum effectiveness. Three categories of pixel processing are described: spatial filters, pixel intensity transforms, and geometric transforms. Bandwidth compression is addressed briefly so that the reader may become familiar with the concept, but the mathematics are not explained.
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