A New Sight for Direct Decorrelation Stretch Techniques

Two decorrelation stretch techniques called Direct Decorrelation Stretch (DDS) and Intensity Conservation DDS (ICDDS) have been recommended for applications on highly correlated multispectral images. This work examines the approaches of DDS and ICDDS in more details and seeks to clarity some apparent misconceptions in saturation stretching. To describe the misconceptions, an IHS substitution (IHSS) technique is proposed. For saturation stretching or image fusion, the fact that the product of saturation value and intensity value equals to a constant value, the hue is unchanged and the saturation value of a pixel is inversely proportional to its intensity value. This fact is crucial to be considered in designing the algorithms.