Design of a High Performance Digital Architecture for Real-Time Correction of Radial Lens Distortion

Abstract

The radial lens distortion correction technique based on least squares estimation corrects a distorted image by expanding it nonlinearly so that straight lines in the object space remain straight in the image space. An absolute pipelined architecture is designed to correct radial lens distortion in images by partitioning the distortion correction algorithm into four main modules. The architecture includes a COKDIC based rectangular to polar coordinate transformation module, a back mapping module for nonlinear transformation of corrected image space to distorted image space, a COKDIC based polar to rectangular coordinate transformation module, and a linear interpolation module to calculate the intensities of four pixels simultaneously in the corrected image space. The system parameters include the expanded/corrected image size, distorted image size, the back mapping coefficients, distortion center and the center of the corrected image. The hardware architecture can sustain a high throughput rate of 30 4-MegaPixel (Mpixels) frames per second (total of 120 Mpixels). The pipelined architecture design will facilitate the use of dedicated hardware that can be mounted along with the camera unit.