The pixel intensities of two channels are plotted against one another in the diagram and each pixel pair with the same X/Y image coordinates is displayed as a point. The frequency with which pixels of a certain brightness occur is visualized with a color palette that is displayed at the bottom of the diagram. The relative value range is between 0-255.

The vertical and horizontal axes show the gray value range of the relevant channel.

The diagram is overlaid with two lines that subdivide it into four quadrants, numbered from 1 to 4. Using the mouse, you can position the lines freely and adjust the threshold values to the data.

The quadrants have the following meanings:

• 1: Non-colocalizing pixels from channel 1
• 2: Non-colocalizing pixels from channel 2
• 3: Colocalizing pixels
• 4: Background