Academic Journals Database
Disseminating quality controlled scientific knowledge

AN IMAGE BASED TECHNIQUE FOR ENHANCEMENT OF UNDERWATER IMAGES

ADD TO MY LIST
 
Author(s): PRABHAKAR C.J. and PRAVEEN KUMAR P.U.

Journal: International Journal of Machine Intelligence
ISSN 0975-2927

Volume: 3;
Issue: 4;
Start page: 217;
Date: 2011;
VIEW PDF   PDF DOWNLOAD PDF   Download PDF Original page

Keywords: Underwater image preprocessing | Homomorphic Filter | Bilateral Filter | BayesShrink | Contrast Equalization

ABSTRACT
The underwater images usually suffers from non-uniform lighting, low contrast, blur and diminished colors. In this paper, we proposed an image based preprocessing technique to enhance the quality of the underwater images. The proposed technique comprises a combination of four filters such as homomorphic filtering, wavelet denoising, bilateral filter and contrast equalization. These filters are applied sequentially on degraded underwater images. The literature survey reveals that image based preprocessing algorithms uses standard filter techniques with various combinations. For smoothing the image, the image based preprocessing algorithms uses the anisotropic filter. The main drawback of the anisotropic filter is that iterative in nature and computation time is high compared to bilateral filter. In the proposed technique, in addition to other three filters, we employ a bilateral filter for smoothing the image. The experimentation is carried out in two stages. In the first stage, we have conducted various experiments on captured images and estimated optimal parameters for bilateral filter. Similarly, optimal filter bank and optimal wavelet shrinkage function are estimated for wavelet denoising. In the second stage, we conducted the experiments using estimated optimal parameters, optimal filter bank and optimal wavelet shrinkage function for evaluating the proposed technique. We evaluated the technique using quantitative based criteria such as a gradient magnitude histogram and Peak Signal to Noise Ratio (PSNR). Further, the results are qualitatively evaluated based on edge detection results. The proposed technique enhances the quality of the underwater images and can be employed prior to apply computer vision techniques
Save time & money - Smart Internet Solutions     

Tango Rapperswil
Tango Rapperswil