In this article

the techniques of fully utilization of system hardware and software resources for increasing computing speed of image geometric correction for mini-computer based digital image processing system are introduced. These techniques are: the refresh memory planes of the image display device are used as the buffer storage of the image data for reducing the number of data transfer between the disk drive and internal memory; two sets of polynomial coefficients are adopted for discarding the redundant computation of non-available image space; and the multiprocess multi-program techniques are used in software implementation. The computing speed of geometric correction of large image data such as the Landsat MSS image data is increased significantly. These techniques have been implemented in the IRSA-2 digital image processing System and can be used in all mini- or micro-computer based digital image processing systems.