There are some different methods used for depth perception. In this paper, a new method for the depth perception, by using a single camera based on an interpolation, is introduced. In order to find the parameters of the interpolation function, a set of lines with predefined distance from camera is used, and then the distance of each line from the bottom edge of the picture (as the origin line) is calculated. The results of implementation of this method show higher accuracy and less computation complexity with respect to the other methods. Moreover, two famous interpolation functions namely, Lagrange and Divided Difference are compared in terms of their computational complexity and accuracy in depth detection by using a single camera. Keywords Depth detection, Camera, Lagrange Interpolation, Divided Difference Interpolation