The app measures the beam profile of a laser beam when used in combination with a target card.

The position of the target card is detected with computer vision techniques, and the corresponding perspective transformation is applied to the target area.

Camera parameters are carefully controlled to ensure a linear response of the camera signal to the incoming light intensity. By recording a sequence of images with different exposure times and sensitivities, a high dynamic range is achieved that enables card detection at low ambient light levels while avoiding saturation of bright laser spots.

The measured beam profile is fitted with Gauss curves and the values for beam widths (D4s) and center position are shown.