Sub-Band Exchange DWT Based Image

Fusion Algorithm for Enhanced Security

Jaypal Baviskar, Afshan MullaImage Processing Department

Intelligent Communication Lab

Mumbai, India

Email: jaypal.baviskar@intelcomlab.com Contact: +91 8983079121

afshan.mulla@intelcomlab.com +919867414095

Overview

• Introduction

• Proposed ‘Sub-band Exchange Image Fusion Algorithm’ Methodology

• Results

• Performance Evaluation

• Conclusion

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Introduction

• Transmission of critical data over the link, in the presence of an attacker has augmented

the demand for secure communication

• In defensive information warfare arena, securing communication between substations &

exchange of confidential data viz. images, text, audio etc. in a secure manner is very

crucial

• Hence, need for robust image encryption methods and security enhancement

techniques has aggravated

• Probability of secret military images being intercepted should be mitigated & the

criticality of the application contexts should be solved

• In this presentation, a Discrete Wavelet Transform (DWT) Sub-band Exchange

based color image fusion scheme for enhanced security is proposed

• An extremely unique algorithm that; Facilitates improvement in security of images that are shared between military base camps,

Provides compression with minimum quality degradation

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Proposed Image Security

Algorithm

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Fig.1: System Model for Image Fusion Technique

A. Mapping RGB Images to Fused

Textured Gray-scale Images

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Fig.2: Original Color Test Image

Fig.3: (a) DWT Applied on Y-Component of both images, (b)

Sub-bands replaced by Original Cb and Cr Components of

switched images

Fig.4: Fused Textured Gray-scale Image

B. Retrieving the Original RGB

Image at Authenticated User end

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Fig.5: Retrieved Cb-Cr Components

of Image1 and Image2

Fig.6: (a) DWT Applied on Textured Gray-scale

Images and Interpolated, to retrieved Y-components

Fig.7: Retrieved RGB Color Images

Result Analysis And

Performance Evaluation

• A. Security aspects of the algorithm

1) The probability of interception (P) = 1 / (Number Of Images to be fused)

2) The number of combinations (n) = NCr

where; N= Number of Images and r = Required images for combination

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Fig.8: Probability of interception by attacker vs.

Number of Images

Fig.9: Possible number of combinations vs. Number

of Images

• B. Comparison of original and recovered RGB image: (RGB Plot)

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Result Analysis And

Performance Evaluation

Fig.10: (a) RGB Plot for Original Image1, (b) RGB Plot for Reconstructed Image1

Fig. 11: (a) RGB Plot for Original Image2, (b) RGB Plot for Reconstructed Image2

• B. Comparison of original and recovered RGB image: (NCC)

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Result Analysis And

Performance Evaluation

Fig.12: Normalized Cross-Correlation Plot of image1

Fig.13: Normalized Cross-Correlation Plot of image2

• C. Evaluation of image quality parameters1. PSNR

2. CR

3. MSE and RMSE

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Result Analysis And

Performance Evaluation

Table 1: Analysis Of Image Quality Parameters

Conclusion

• The algorithm implemented in this paper facilitates enhanced security as well as quality

conscience compression ratio

• It is based on an extremely unique method known as 2-level DWT based Sub-band

Exchange Image Fusion Technique

• Conversion of RGB images to fused textured gray-scale images provides acceptable

compression for military image database

• The bandwidth utilization and processing time required for transmission of these images

is minimized to great extent

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Conclusion

• It facilitates improved security, in terms of preventing the attacker from getting hold on

images transmitted over the link, since chrominance components are randomly

swapped

• Offers high compression ratio, maintaining good PSNR value, thereby mitigating errors

• The algorithm is a highly reliable and competitive image encryption scheme in image

processing domain

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Thank You