主动离焦三维测量的调制度全局计算方法

Full-field calculation of active depth from defocus

提出了离焦三维测量的全局计算方法。通过向物体投射正弦光栅,使物体上任一点的光分布在光栅频率(局域傅里叶变换)处的光强度等于该处的调制度,利用拍摄物体的两幅离焦像的调制度之比,得到了物体的深度分布。不但消除了过去主动离焦三维测量采用局域傅里叶变换带来的测量误差,同时计算程序简单、速度快,具有较好的实用性。

The full-field calculation of active depth from defocus is proposed. When an object is projected with sinusoidal grating, the light intensity of the object at the projected frequency on the measured point is equal to the modulation of the same point. By using the ratio of the modulation distributions of the two defocus images, the depth of the object can be calculated. The method not only eliminated the transverse and longitudinal resolving power limited in the other depth from defocus by using short time Fourier transformation but also may be calculated with simply and apace. The method can be applied to active depth from defocus easily and efficiently.