Patent ID: 7920150

Claim:
An image scaling system capable of saving memory, provided for shrinking and expanding an image consisting of plural image lines, the system comprising: a window memory, which receives and temporarily stores partial data of N image lines, where N is a positive integer; a first direct memory access (DMA), which is coupled between a main memory and the window memory in order to read the partial data of the N image lines from the main memory and write the partial data of the N image lines to the window memory; a longitudinal scaler, which is connected to the window memory in order to perform a longitudinal scaling operation on the partial data of the N image lines to thereby produce partial data of a longitudinal image line; a buffer, which is connected to the longitudinal scaler in order to receive and temporarily store the partial data of the longitudinal image line; a latitudinal scaler, which is connected to the buffer in order to perform a latitudinal scaling operation on the partial data of the longitudinal image line to thereby produce scaling-part data of a latitudinal image line; an output buffer, which is connected to the latitudinal scaler in order to store the scaling-part data of the latitudinal image line; and a second DMA, which is coupled between the main memory and the output buffer in order to read the scaling-part data of the latitudinal image line from the output buffer and write the scaling-part data of the latitudinal image line to the main memory; wherein the longitudinal scaler and the latitudinal scaler use a window average to perform a shrinking operation for shrinking the image, and a bi-linear interpolation average to perform an expanding operation for expanding the image.