07-04-2016, 09:39 AM
image denoising using adaptive wavelet thresholding
Abstract
The NeighShrink, IAWDMBNC, and IIDMWT are important methods to remove the noise from a corrupted image. These methods however cannot recover original image significantly since the threshold value does not minimize the noisy wavelet coefficients across scales and thus they do not give good quality of image. In this paper, we propose an adaptive denoising method that provides an adaptive way of setting up minimum threshold by shrinking the wavelet coefficients to overcome the above problem using an exponential function. Our method retains the original image information efficiently by removing noise and it has the image quality parameters such as peak-to-signal nose ratio (PSNR) and Structural Similarity Index Measure (SSIM) better than the NeighShrink, IAWDMBNC, and IIDMWT methods.Recently, image denoising using the wavelet transform has been attracting much attention. Wavelet based approach provides a particularly useful method for image denoising when the preservation of image features in the scene is of importance. In this paper, we propose a novel denoising method for removing additive noise present in the underwater images. In addition to scattering and absorption effects, macroscopic floating particles producing images of the size of a pixel can be present as well due to sand raised by the motion of a diver, or small plankton particles. These particles are part of the scene, but cause generally unwanted signal. We see them as an additive noise. The problems it causes in feature extraction. In the proposed denoising method, first we use homomorphic filtering for correcting non uniform illumination, then we apply anisotropic filtering for smoothing. After smoothing, we apply adaptive wavelet subband thresholding with Modified Bayes-Shrink function. We compared and evaluated the proposed denoising method based on the Peak Signal to Noise Ratio (PSNR). The experimental result shows that the proposed method yields superior result for underwater noisy images compared to other denoising techniques.
Abstract
The NeighShrink, IAWDMBNC, and IIDMWT are important methods to remove the noise from a corrupted image. These methods however cannot recover original image significantly since the threshold value does not minimize the noisy wavelet coefficients across scales and thus they do not give good quality of image. In this paper, we propose an adaptive denoising method that provides an adaptive way of setting up minimum threshold by shrinking the wavelet coefficients to overcome the above problem using an exponential function. Our method retains the original image information efficiently by removing noise and it has the image quality parameters such as peak-to-signal nose ratio (PSNR) and Structural Similarity Index Measure (SSIM) better than the NeighShrink, IAWDMBNC, and IIDMWT methods.Recently, image denoising using the wavelet transform has been attracting much attention. Wavelet based approach provides a particularly useful method for image denoising when the preservation of image features in the scene is of importance. In this paper, we propose a novel denoising method for removing additive noise present in the underwater images. In addition to scattering and absorption effects, macroscopic floating particles producing images of the size of a pixel can be present as well due to sand raised by the motion of a diver, or small plankton particles. These particles are part of the scene, but cause generally unwanted signal. We see them as an additive noise. The problems it causes in feature extraction. In the proposed denoising method, first we use homomorphic filtering for correcting non uniform illumination, then we apply anisotropic filtering for smoothing. After smoothing, we apply adaptive wavelet subband thresholding with Modified Bayes-Shrink function. We compared and evaluated the proposed denoising method based on the Peak Signal to Noise Ratio (PSNR). The experimental result shows that the proposed method yields superior result for underwater noisy images compared to other denoising techniques.