The SIFT operator is popularly used in pattern recognition and image matching since it is invariant to image rotation,scale,addition of noise,illumination changes and affine distortion. But the process requires to calculate the whole scale spaces of the input image that will cost very expensive time and take up a lot of memory resources. Especially for the large aerial image,the SIFT operator cannot process and doesn't generate keypoints. Therefore the paper implemented the improved SIFT operator based on i...