Image name: Lena.pgm
Original Image Format: PGM
Original Image Size: 2622159 bytes

Size after compression using my tool(without Huffman Encoding): 217268 bytes
Compression Ratio: 12.07
Size after compression using my tool and adaptive Huffman Encoding & LZ77: 39078 bytes
Compression Ratio: 67.10

Size obtained after doing standard JPEG compression: 32194 bytes
Compression Ratio: 81.45

(I have converted the PGM images to JPEG's as netscape does not display PGM images)

The Original and Reconstructed Images :-
 

Original Image	Image after compression and decompression

Zoomed in portions of the original and the Reconstructed images showing blocking artifacts inherent in the JPEG scheme :-
Both images are at 800% Zoom.
 

Zoomed in portion of original Image	Zoomed in portion of the reconstructed image

Though my JPEG implementation shows significant blocking, actual JPEG implementations are slightly better and show lesser blocking

Page last updated on 28 January, 2004.	AT cse.iitd.ac.in	© Parag Chaudhuri , 2009