It's useful when you want to get the idea of the color range of an image, quickly detect negative color values and the alpha values below 0 and above 1, which may cause some compositing errors downstream.
The measured values are displayed in the Control Panel of the macro.
The tool also renders additional information on top of the analyzed image:
- Draggable and resizeable text output box with the miximum and maximum channel values
- Areas with color values below the defined threshold are filled with magenta (by default, those are negative colors).
- Areas with color values above the defined threshold are filled with green (by default, those are color values above 1).
- The out-of-range areas are surrounded by white contour for easier visual detection in case the areas are too small.