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Next: Pixel Maps Up: 13.2 Colors and Color Previous: 13.2.2 Pixel Scale and   Contents

13.2.3 Look-Up Tables

One useful tool for color modification is the look-up table. Generally speaking, a look-up table maps an input value to a location in a table, and replaces that value with the table entry. Two look-up tables in OpenGL, pixel maps and color tables, map components independently in one-dimensional tables. These mechanisms provide efficient mapping for applications requiring no correspondence between the channels of the image. A third mechanism, pixel texturing, uses the OpenGL texturing capability to perform multi-dimensional look-ups.