A method is to implement a Scale Invariant Feature Transform algorithm in a shared memory multiprocessing system. The method comprises building differences of Gaussian (DoG) images for an input image, detecting keypoints in the DoG images; assigning orientations to the keypoints and computing keypoints descriptors and performing matrix operations. In the method, building differences of Gaussian (DoG) images for an input image and detecting keypoints in the DoG images are executed for all scales of the input image in parallel. And, orientation assignment and keypoints descriptions computation are executed for all octaves of the input image in parallel.