A VLSI Design of Image Rotation for Real Time 2-D Barcode Identification

Abstract

Image rotation is a necessity for 2-D barcode identification. The computation complexity of image rotation is considered as a key problem of the implementation of real time 2-D barcode identification. This paper presents a novel VLSI structure for image rotation which can calculate the tilt angle of 2-D barcode image and rotate image to the horizontal way. The circuit to calculate the tilt angel of 2-D barcode is simple and effective and can be implemented with low hardware complexity. Image rotation algorithm takes use of improved CORDIC algorithm and Bi-linear interpolation and is implemented by high-speed pipelined architecture. The proposed architecture is implemented on the Altera Stratix IV FPGA. Experimental results show that the proposed architecture can rotate 2-D barcode images with arbitrary tilt angles to the horizontal way at 132MHz. Moreover, it can keep image details clear thus improving 2-D barcode identification rate.