Ideally, one would like to easily and accurately obtain dye concentration at every point. Our objective was to develop a method for calculating dye concentration at each point in a color image. The method should be convenient, objective, and give accurate information for each point. Our eyes have receptors that are sensitive to ranges of wavelengths corresponding to what we call red, green, and blue. Intermediate colors are produced by stimulation of these three receptors in particular proportions.
Color space is a way of displaying individual colors as locations in space.
If a uniform soil surface, free of litter, is displayed as points in RGB space, the points will fall on a line passing near or through the origin. Differences in light intensity are largely due to differences in water content, shading and microtopography. A dyed soil will fall on a different line, but will also pass through the origin. If we plot an undyed and a dyed soil in color space, we will see differences between them. The color space that provides the clearest difference between the two is likely to be the most useful one for analysis.