Depth map building based on pixel number variation and SURF

This paper presents a method for depth measurement based on Speeded Up Robust Features (SURF) and pixel number variation of CCD Images. A single camera is used to capture two images in different photographing distances, where features in the images are extracted and matched by SURF. To remove false matching points, an Identifying point correspondences by Correspondence Function (ICF) method is adopted to automatically select suitable reference points required for the pixel number variation method. Based on the displacement of the camera at two photographing distances, difference in pixel count between feature points of the objects in the images can be used to determine the photographing distance of the target objects for constructing the depth map by linear interpolation.