Interferograms are made by interfering wave fronts and hence contain important information about them. Analysis of interferograms requires the identification of all the fringes and their extrema. Here an algorithm for computer tracing of interference fringes is described. The method uses a Fourier filter for removing high frequency noise, a local averaging for binarization of images not having uniform intensity distribution, scanning the interferogram locally both horizontally and vertically to determine the type of the scan, local application of simultaneous horizontal and vertical scans for tracing of complicated fringe patterns, and removal of the noise from the traces by determining the number of connected pixels. The proposed algorithm was found to yield good result even for high noise images.