Locating Micrometer in a Digital Image Based on Projection Algorithm in Space Domain

Based on the gradation characteristic and the geometry characteristic of a micrometer, a simple method for automatically locating the micrometer in an image is presented in this paper. The proposed method adopts the horizontal and vertical projection of the image, as well as some simple rules to segment the micrometer areas. Then the relationship between the graduation line and pixels is computed to measure the pixel interval in the image. The experimental results on the micrometer images taken under different light conditions and angles show the efficiency and the high accuracy of the proposed method.