Patent ID: 7006688

Claim:
A computer with a monitor viewable program that executes to display a histogram of image data on the monitor, the monitor contemporaneously displaying a screen image viewed on a monitor displaying the histogram, and displays a digital or analog control element that controls both compression and expansion of midtones, wherein activation of the midtone compression/expansion element accordingly alters the displayed image according to effects of programs underlying the control of the element, this histogram display and element being associated on a single logical screen display in which at least one other image data modification effect is present on the screen image as a cursor addressable or keyboard selectable image data modification effect, wherein luminance of the image is calculated from a combination of the RGB channels for a color image or by using the brightness values directly for a grayscale image and clipping is effected by converting all channel values below a threshold T to the value Ymin so that the remaining values lie from T to Xmax and then linearly stretching these latter values to the interval Xmin to Xmax.