Presented in the National Level Technical Symposium on Emerging Trends in Technology [TECHNOVISION ’10, G.N.D.E.C. Ludhiana, Punjab, India- 9th-10th April, 2010]

1. REDUCTION OF BLOCKING ARTIFACTS
IN
JPEG COMPRESSED IMAGE
Submitted By:-
Sukhpal Singh
B.Tech. (C.S.E.)
Computer Science and Engineering Department
Guru Nanak Dev Engineering College, Ludhiana, Punjab, India

2. IMAGE COMPRESSION

process of transforming the data description into a more concise and
condensed form

improves the storage efficiency, communication speed, and security

The shorter the data description, usually the better

people are interested in the information and not in the data

DATA = REDUNDANT DATA + INFORMATION

3. TYPES OF REDUNDANCY

Coding Redundancy

Interpixel Redundancy

Psychovisual Redundancy

4. IMAGE COMPRESSION MODEL
f(x,y)
Source
Encoder
f(x,y)
Channel
Encoder
Source
Decoder
Channel
Channel
Decoder

5. COMPRESSION TECHNIQUES

Lossless Image Compression

Lossy Image Compression

6. LOSSLESS IMAGE COMPRESSION

restored data file is identical to the original

used where the loss of information is unacceptable

decompressed image is exactly same as the original image

reversible in nature
=

7. LOSSY IMAGE COMPRESSION






restored data file is identical to the original
based on the concept that all real world measurements inherently
contain a certain amount of noise.
If the changes made to these images, add a small amount of additional
noise, no harm is done.
higher the compression ratio, the more noise added to the data.
decompressed image is as close to the original as we wish
irreversible
=

8. JPEG

JPEG stands for Joint Photographic Experts Group

designed for compressing full-color or gray-scale images of natural,
real-world scenes

JPEG achieves much greater compression than with other lossless
methods

involves lossy compression through quantization

9. JPEG
Usage of JPEG compression method is motivated because of
following reasons:
The compression ratio of lossless methods is not high enough for
image and video compression

JPEG uses transform coding, it is largely based on the following
observations:

10. STEPS IN JPEG COMPRESSION

11. JPEG
Actual Image
Blocked Image

12. Conclusion

The artifacts are removed to some extent .

Increase the subjective as well as objective quality of the images.

Increase the PSNR value of the images.

13. THANK YOU