QRT Ray Tracer bitmap
QRT Ray Tracer bitmap image is the default output format of the QRT Ray Tracer (also known as Quick Ray Tracer or QRT) software. It is an uncompressed truecolor raster image format.
It is not to be confused with the QRT Ray Tracer scene description format (.QRT).
Files have a 4-byte header, containing the width and height. Each row has a 2-byte prefix containing the row number.