Self-correction phase unwrapping method based on Gray-code light

摘要

Gray-code light projection phase unwrapping method combined with phase shift technique can test objects with complex or discontinuous surface. But the captured Gray-code patterns are always not sharp cut-off in the black and white conversion boundaries, which may introduce wrong decoding phase order and lead to 2n phase errors in the unwrapped phase. In the experiment, each of the wrong phase order jumps is limited in the range of some pixels distance difference from its nearest 2n phase jump along the X direction in the wrapped phase. These phase jumps are used to correct the decoding results in order to avoid 2n phase errors. A self-correction phase unwrapping method is proposed which can yield reliable unwrapped phase for 3-D shape measurement.