In this example, the Alpha values are specified to be representative of the magnitude of the corresponding input data, and the weighting tables are designed such that the stronger of the two inputs are output at each point. If Alpha-2 is less than Alpha-1 then the output consists solely of RGB-1, while if Alpha-2 is greater than Alpha-1 then the output consists solely of RGB-2. This approach is common with ultrasound tissue intensity + flow velocity images, where each output pixel would be either a grayscale tissue value if the flow value is less than the tissue value or a colorized flow velocity value if the flow value is greater than the tissue value: