Abstract. This paper introduces a very simple method to achieve a saturation (decorrelation) stretch without coordinate transformation, the Direct Decorrelation Stretch (DDS) technique. In RGB (red, green and blu) colour coordinate space, a colour vector can be expressed in terms of an achromatic component and a chromatic (pure colour) component. A direct decorrelation stretch of a RGB colour image is achieved by decreasing the magnitude of the achromatic component of the colour vector for the pixel being processed. Initially, the R, G, and B digital numbers (DNs) for each colour pixel are examined and the lowest value (it could be the red, green or blue) is selected. A fixed ( user controlled) proportion of the selected lowest DN is then subtracted from each of the original R, G and B DNs of this pixel. The result of the subtraction, based on RGB pixel minimum values, is an image with reduced achromaeity. This corresponds to increased saturation.