1. An apparatus for automatically generating a three-dimensional look-up table (3D LUT) representing image processing, comprising: a digital image input for receiving digital image data; a test signal generator configured to generate digital test patterns; an image processor configured to perform color conversion on received image data and generate converted digital image data; a first switch coupled for providing either the digital image data from the digital image input or the digital test patterns from the test signal generator to the image processor; a red/green/blue (RGB) value measurement circuit coupled to the image processor and configured to measure RGB values from the converted digital image data; and a digital image output coupled to the image processor for providing the converted digital image data to an external display.