Estimating surface roughness using image focus

摘要

Estimation of surface roughness is an important parameter for many applications including optics, polymers,semiconductor etc. In this paper, we propose to estimate surface roughness using one of the 3D shape recovery opticalpassive methods, i.e., shape from focus. Three-dimensional shape recovery from one or multiple observations is achallenging problem of computer vision. The objective of shape from focus is to calculate the depth map. That depthmap can further be used in techniques and algorithms leading to recovery of three dimensional structure of object whichis required in many high level vision applications. The same depth map can also be used for surface roughnessestimation. One of the requirements, of researchers is to quickly compare the samples being fabricated based on variousmeasures including surface roughness. However, the high cost involved in estimation of surface roughness limits itsextensive and exhaustive usage. Therefore, we propose an inexpensive and fast method based on Shape From Focus(SFF). We use two microscopic test objects, i.e., coin and TFT-LCD cell for estimating the surface roughness.