Fast image interpolation algorithm based on gradient

Traditional image interpolation algorithms have poor performance and most of the recently developed edge-directed interpolation algorithms are of high computation.To solve those problems,a fast image interpolation algorithm based on gradient distribution detection was proposed.The basic idea was to detect the existence of edges in each 3×3 neighbourhood of the original low-resolution image by calculating its two-step gradients.If an edge existed,adaptive weighted factor up to edge strength was obtained by calculating its one-step gradient,and then the weighted linear interpolation was implemented.Otherwise,bilinear interpolation was carried through in that neighbourhood.The experiments show that the proposed algorithm is able to not only keep the subjective visual quality of the interpolated high-resolution image with whole clarity and edge smoothness,but also reduce the operation time by at least 20% compared with the equivalent algorithms now available.It contributes to an image enlargement application in embedded systems.