Robust Segmentation Method for Noisy Images Based on an Unsupervised Denosing Filter

Level-set-based image segmentation has been widely used in unsupervised segmentation tasks.Researchers have recently alleviated the influence of image noise on segmentation results by introducing global or local statistics into existing models.Most existing methods are based on the assumption that the distribution of image noise is known or observable.However,real-time images do not meet this assumption.To bridge this gap,we propose a novel level-set-based segmentation method with an unsupervised denoising mechanism.First,a denoising filter is acquired under the unsupervised learning paradigm.Second,the denoising filter is integrated into the level-set framework to separate noise from the noisy image input.Finally,the level-set energy function is minimized to acquire segmentation contours.Extensive experiments demonstrate the robustness and effectiveness of the proposed method when applied to noisy images.

No-reference noisy image quality assessment incorporating features of entropy, gradient, and kurtosis

Noise is the most common type of image distortion affecting human visual perception.In this paper,we propose a no-reference image quality assessment(IQA)method for noisy images incorporating the features of entropy,gradient,and kurtosis.Specifically,image noise estimation is conducted in the discrete cosine transform domain based on skewness invariance.In the principal component analysis domain,kurtosis feature is obtained by statistically counting the significant differences between images with and without noise.In addition,both the consistency between the entropy and kurtosis features and the subjective scores are improved by combining them with the gradient coefficient.Support vector regression is applied to map all extracted features into an integrated scoring system.The proposed method is evaluated in three mainstream databases(i.e.,LIVE,TID2013,and CSIQ),and the results demonstrate the superiority of the proposed method according to the Pearson linear correlation coefficient which is the most significant indicator in IQA.

An Improved Pigeon-Inspired Optimization for Multi-focus Noisy Image Fusion

Image fusion technology is the basis of computer vision task,but information is easily affected by noise during transmission.In this paper,an Improved Pigeon-Inspired Optimization(IPIO)is proposed,and used for multi-focus noisy image fusion by combining with the boundary handling of the convolutional sparse representation.By two-scale image decomposition,the input image is decomposed into base layer and detail layer.For the base layer,IPIO algorithm is used to obtain the optimized weights for fusion,whose value range is gained by fusing the edge information.Besides,the global information entropy is used as the fitness index of the IPIO,which has high efficiency especially for discrete optimization problems.For the detail layer,the fusion of its coefficients is completed by performing boundary processing when solving the convolution sparse representation in the frequency domain.The sum of the above base and detail layers is as the final fused image.Experimental results show that the proposed algorithm has a better fusion effect compared with the recent algorithms.