Grayscale Image Compression using Discrete Cosine Transform

  Mr. Amit D. Landge,  Mr. S. M. Lichade,  Mr. S. A. Bagal

Image compression is the reduction or elimination of redundancy in data representation in order to achieve reduction in storage and communication cost. [1] Discrete cosine transform (DCT) is computationally intensive algorithm it has lot of electronics application. DCT transforms the information time or space domain into frequency domain to provide compact representation, fast transmission and memory saving. [1]. DCT is very effective due to symmetry and simplicity. In this project we have used an intensive algorithmic flow for image compression, reconstruction of original image and error computation between original image and reconstructed image. This algorithmic flow used MATLAB-XILINX-MATLAB approach for mapping and loading process. For Grayscale image compression using DCT, initially selected 256*256 image and access or read this image for DCT computation, Then found that image pixels get reduced after DCT process, that means ultimately image get reduced. Similarly selection has modified for different images i.e. 64*64 and 8*8 images then got same compressed image after DCT image compression. After DCT computation here computed IDCT for reconstruction of image. Image reconstruction means whatever image pixels have compressed for a particular use need to decompress it also calculated, error image between original images and reconstructed image. In this project, the input image need to compress, that access/read into MATLAB and computed DCT and IDCT process over original image and calculated error between original image and reconstructed image. Similarly original image accessed into Xilinx through MATLAB using Mapping Process to implement DCT, IDCT and Error Image to compress and decompress a particular image. MATLAB is very much efficient and useful to take out each image pixels from original image also very helpful to load .txt file format from XILINX. The coding is simulated using XILINX 13.4 ISE and final error image shown through MATLAB 7.0.4

Keywords- Discrete Cosine Transform (DCT), Inverse Discrete Cosine Transform (IDCT), VERILOG Hardware Descriptive Language (VERILOG HDL), Very High Speed Integrated Circuit Hardware Descriptive Language (VHDL), Joint Photographic Expert Group (JPEG).

Unique Identification Number - IJEDR1602242
Page Number(s) - 1359-1366
Pubished in - Volume 4 | Issue 2 | June 2016
DOI (Digital Object Identifier) -   
Publisher - IJEDR (ISSN - 2321-9939)

  Mr. Amit D. Landge,  Mr. S. M. Lichade,  Mr. S. A. Bagal,   "Grayscale Image Compression using Discrete Cosine Transform", International Journal of Engineering Development and Research (IJEDR), ISSN:2321-9939, Volume.4, Issue 2, pp.1359-1366, June 2016, Available at :http://www.ijedr.org/papers/IJEDR1602242.pdf