Opt Express. 2023 Feb 13;31(4):5200-5214. doi: 10.1364/OE.477180.
An imaging setup that enables unsynchronized photometric stereo (PS) for Lambertian objects based on modulated light sources is presented. Knowing the specific frequency of the modulated light source allows to filter out any other light in the scene. This creates an image that depends only on the particular light source while ignoring the ambient light. Moreover, if the scene is illuminated by multiple modulated sources with different frequencies, repeating this process for every frequency will produce a sequence of images with the corresponding illumination. This sequence is then used as an input to the PS algorithm for 3D reconstruction. The proposed approach, named Light Invariant Photometric Stereo (LIPS), was verified on both synthetic and real-world data. LIPS eliminates the need for synchronization between the sources and the camera and significantly outperformed the classical PS method in an illuminated environment.
提出了一种基于调制光源的非同步光度立体（PS）成像设置，适用于朗伯物体。了解调制光源的特定频率可以滤除场景中的任何其他光线。这创建了一个仅依赖于特定光源而忽略环境光的图像。此外，如果场景由多个具有不同频率的调制光源照明，则对每个频率重复此过程将生成具有相应照明的图像序列。然后，将该序列用作 PS 算法进行 3D 重建的输入。所提出的方法称为光不变光度立体（LIPS），已在合成和真实世界数据上进行了验证。LIPS 消除了光源和相机之间同步的需求，并在照明环境中显著优于经典 PS 方法。
