In a method of image subtraction a series of frames of a subject are taken using a video camera.

Temporally-interleaved image-subtraction reduces the magnitude of motion clutter and has no adverse effect on the desired ambient-light cancellation of static images.

Embodiments of image-generation devices employing temporally-interleaved image-subtraction include single, double, triple, and series accumulator configurations.

Image subtraction is often used to identify changes that have occurred between images collected on different dates.

Temporally-interleaved image subtraction is particularly well suited for use in video eyetracking applications where ambient light and scene motion can cause significant problems.

Image subtraction methods are used to detect wafer defects, which are reported to a main computer (50) to aid in statistical process control, particularly for manufacturing equipment.