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Digital Watermarking – Comparison of DCT and DWT methods

version 1.2.3 (1020 KB) by Nikola Jovanovic
Robustness of DWT vs DCT is graded based on the quality of extracted watermark. The measure used is the Correlation coefficient (0-100%).

149 Downloads

Updated 27 Aug 2021

From GitHub

View license on GitHub

DWM View Digital Watermarking – Comparison of DCT and DWT methods on File Exchange License: MIT GitHub (pre-)release

Keywords:

DWM, Digital Watermarking, Digital Watermark

DWT, Discrete Wavelet Transform

DCT, Discrete Cosine Transform

Digital Image processing

Basic Overview

Digital Watermarking (DWM) is a technique of protecting digital data. This code base implements 2 methods for marking digital images based on Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT).
Several attacks (signal degradations such as noise, dithering, filtering, cropping, lossy JPEG compression) on marked image were conducted. Attacked images are saved and the watermark is extracted.
Robustness of DWT vs DCT is graded based on the quality of extracted watermark. The measure used is the Correlation coefficient (0-100% or 0-1).

Flowchart

Flowchart

Discrete Wavelet Transform Breakdown

DWT_Breakdown DWT_Breakdown0
DWT_Breakdown1 DWT_Breakdown2

Using the App

Main >> MethodSelection >> AttackSelection

Example Log

Case: No watermark, no attak, no detection

Not marked. Watermark method: None.
Attack: None
C:\Users\dzoni\Documents\GitHub\watermark\output\marked\Marked_image_None.tif
Not detected. Watermark method: None.

 Correlation Coefficient of the watermarks   NaN
 Normalized Correlation of the watermarks   0.000000
 Correlation Coefficient of the images   1.000000
 Normalized Correlation of the images   1.000000  

 Num of bit errors in detected watermark 2635   
 BER [%] for detected watermark 64.331055  
*******************************************************

Case: Watermarked, no attak, detection comparison

Method: DCT
Attack: None
C:\Users\dzoni\Documents\GitHub\watermark\output\marked\Marked_image_DCT.tif

 Correlation Coefficient of the watermarks   0.995758
 Normalized Correlation of the watermarks   0.996964
 Correlation Coefficient of the images   0.999543
 Normalized Correlation of the images   0.999996  

 Num of bit errors in detected watermark 8   
 BER [%] for detected watermark 0.195313  
*******************************************************
Method: DWT
Attack: None
C:\Users\dzoni\Documents\GitHub\watermark\output\marked\Marked_image_DWT.tif

 Correlation Coefficient of the watermarks   1.000000
 Normalized Correlation of the watermarks   1.000000
 Correlation Coefficient of the images   0.998351
 Normalized Correlation of the images   1.000107  

 Num of bit errors in detected watermark 0   
 BER [%] for detected watermark 0.000000  
*******************************************************

References:

Nikola Jovanovic on ResearchGate
Digital Watermarking – Comparison of DCT and DWT methods, ResearchGate
Digital Watermarking in Wavelet domain – Comparison of different types of wavelets, ResearchGate

Download

Download the latest release here.

Cite As

Nikola Jovanovic (2021). Digital Watermarking – Comparison of DCT and DWT methods (https://github.com/etfovac/watermark/releases/tag/v1.2.3), GitHub. Retrieved .

MATLAB Release Compatibility
Created with R2008b
Compatible with R2008b to R2018a
Platform Compatibility
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To view or report issues in this GitHub add-on, visit the GitHub Repository.
To view or report issues in this GitHub add-on, visit the GitHub Repository.