IDCT design for JPEG decompression in an electronic ballot box

This paper describes the design of a inverse discrete cosine transform (IDCT) to decompress JPEG images. The target application is the decompression of monocromatic photos of candidates in the Brazilian Electronic Ballot Box. The goals is to develop a constrained implementation which targets a XC4010 FPGA. It is based on the application of two 1-D IDCTs using a local memory as buffer. The design resulted in around two hundred logic cells for a two-pass IDCT, which was implemented and tested in the Xilinx demo board.