The accuracy of phase-measuring profilometry is greatly influenced by environmental light, especially outdoors. The errors caused by changes of the environmental light are analyzed, and some simulated fringe patterns are processed. A new calibration algorithm, which performs intensity background and fringe amplitude transformations, is proposed. Theoretical analysis and experimental results verify that the improved phase-measuring profilometry is insensitive to the change of environmental light. © 2001 Society of Photo-Optical Instrumentation Engineers.