Selection of transforms for better image compression
DSpace at IIT Bombay
View Archive InfoField | Value | |
Title |
Selection of transforms for better image compression
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Creator |
RAJPUT, N
SHEVGAONKAR, RK |
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Subject |
image compression
transforms dct wht mixed transforms |
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Description |
This paper investigates the compactness aspect of two transforms namely DCT and WHT. We define a parameter called Activity Index (AI) of the image which is the ratio of the first derivative energy in the edges and the total first derivative energy of the image. Sobel edge operator is used to obtain the edges in the image and the first derivative energy in these edges is computed. It is demonstrated that the activity index provides a good measure of the relative compression which the two transforms would give and therefore can help in choosing the transform for better compression of an image. Computations show that the WHT performs better for images having higher AL(close to 1) whereas if the AI is small(less than 0.5) the DCT's performance is superior. If AI is close to 0.5 both transforms give more or less same compression. The algorithm is tested on a variety of natural as well as robotic type of images.
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Publisher |
SPIE-INT SOC OPTICAL ENGINEERING
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Date |
2011-10-23T17:53:33Z
2011-12-15T09:11:16Z 2011-10-23T17:53:33Z 2011-12-15T09:11:16Z 1998 |
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Type |
Proceedings Paper
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Identifier |
APPLICATIONS OF DIGITAL IMAGE PROCESSING XXI,3460,468-477
0-8194-2915-5 0277-786X http://dx.doi.org/10.1117/12.323201 http://dspace.library.iitb.ac.in/xmlui/handle/10054/15194 http://hdl.handle.net/100/1960 |
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Source |
Conference on Applications of Digital Image Processing XXI,SAN DIEGO, CA,JUL 21-24, 1998
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Language |
English
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