Control the presentation of the “superposition waveform” in the top panel.

PIXEL = A-B

The waveform shown in the top panel will be calculated by subtracting pulse amplitudes of the B-waveform from the corresponding pulse amplitudes of the A-waveform.

This is the default choice.

PIXEL = B-A

The waveform shown in the top panel will be calculated by subtracting pulse amplitudes of the A- waveform from the corresponding pulse amplitudes of the B-waveform.