Method and system for digital image magnification and reduction

Abstract

An image scaling system for converting a sampling rate of an input video signal comprising input pixel data to produce a magnified or reduced output video image comprising output pixel data includes a first one-dimensional image scaler comprising a single-stage finite-duration impulse response (FIR) filter structure with poly-phase filter responses that receives and scales the input pixel data by a scaling factor in either a horizontal or vertical direction to produce output pixel data and a second one-dimensional image scaler comprising a single-stage FIR filter structure that is coupled in tandem to the first one-dimensional image scaler and scales by the scaling factor the output pixel data from the first one-dimensional image scaler in a direction perpendicular to that of the first one-dimensional image scaler to produce the magnified or reduced output video image. Each of the first and second one-dimensional image scalers includes a reconfigurable interpolation unit that allows each single-stage FIR filter structure to switch back and forth between operating in a direct-form FIR filter mode and a transposed-form FIR filter mode while using a fixed set of system resources such that a wide range of image magnification and reduction scaling factors can be achieved using the fixed set of system resources.