Explosion of multidimensional image histograms

Enhancement of multispectral and true-color images is frequently accomplished by histogram modification. The color components are generally separately adjusted within an appropriate, often perceptually based, color coordinate system. However, independent component modification is seldom able to exploit the full extent of the RGB gamut unless some color values are clipped at the RGB boundaries. Further improvement in color contrast is sometimes more important than preserving perceptual attributes. For example, color composites derived from multispectral images have little basis in human perception and thus need not be perceptually constrained. "Histogram explosion", a new concept for multivariate enhancement, enables the full RGB extent to be exploited without clipping. While the algorithm is not generally based upon a perceptual model, original hue values may be preserved with proper parameter choices. The paper presents details of the histogram explosion method, an analysis of its computational complexity, and some experimental results.