Noise-enhanced contrast stretching of dark images in SVD-DWT domain
01 Dec 2013-pp 1-6
TL;DR: A noise-enhanced contrast stretching algorithm for enhancement of dark images in SVD-DWT domain has been presented and comparison with other SR-based and non-SR based algorithms shows noteworthy performance of the algorithm.
Abstract: A noise-enhanced contrast stretching algorithm for enhancement of dark images in SVD-DWT domain has been presented in this paper. A dark or low-contrast image is considered to be comprising a weak signal (information) and noise (due to insufficient illumination). Since singular values of an image represent luminance of independent image layers, the internal noise may be considered to be inherent in the singular values of the image, as well that of the wavelet approximation coefficients of a dark image. The singular values of the approximation coefficients are iteratively processed using the analogy of a double-well system exhibiting dynamic stochastic resonance (SR), where addition of noise is utilized to enhance system performance. Iteration is terminated with the criterion of target contrast and visual qualities. Comparison with other SR-based and non-SR based algorithms shows noteworthy performance of the algorithm in the SVD-DWT domain.
Citations
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TL;DR: The proposed noise-enhanced iterative processing on Fourier coefficients for enhancement of low-contrast images has been found to give noteworthy performance for both low- Contrast and dark images among the SR-based techniques and is found to be better than most of the non-SR- based techniques, in terms of contrast enhancement, perceptual quality and colorfulness.
Abstract: This paper presents a study of noise-enhanced iterative processing on Fourier coefficients for enhancement of low-contrast images. The processing equation is derived from the concept of dynamic stochastic resonance (SR), where the presence of optimum amount of noise produces an improved performance in the system. Similar to our earlier works on SR-based contrast enhancement, noise in the current context is the internal noise inherent in an image due to insufficient illumination. Here, however, the parameter selection is done so as to achieve large noise suppression. Iteration is terminated when target performance has been achieved. It is observed that the increase in the variance of the Fourier magnitude distribution leads to an increase in the contrast of the image. The increase in the variance is analytically proven to be equivalent to the process of coefficient rooting. Comparison has been made with various state-of-the-art SR and non-SR-based techniques in spatial/frequency domains. The proposed technique has been found to give noteworthy performance for both low-contrast and dark images among the SR-based techniques. The performance is also found to be better than most of the non-SR-based techniques, in terms of contrast enhancement, perceptual quality and colorfulness.
12 citations
TL;DR: An extensive literature review was conducted and the nighttime visual refinement approaches into nighttime restoration and enhancement were classified and identified the research gap fields to explore future research directions in nighttime visual enhancement techniques.
Abstract: Video surveillance systems substitute manual efforts in various safety critic domains such as border area, assisted living, banking, service stations, and transportation. The multimedia-based surveillance system has a significant role in security and forensic systems because people tend to be easily convinced after observing voice, image, and video. Hence, these videos are strong evidence in the forensic investigation. However, most of the criminal activities such as ATM robbery and assassination are occur at nighttime because of the crime supporting dark environment. Many of the night surveillance systems in military, as well as commercial applications, are equipped with infrared and thermal based night vision systems. Its poor capability of texture and color interpretations are the major issues to ensure secure nighttime video monitoring. Specifically, visual refinements of nighttime surroundings and foreground objects provide a valuable assistance in the nighttime security system. In this scenario, it is highly recommended a review of the state-of-the-art nighttime visual refinement approaches. We conducted an extensive literature review and classified the nighttime visual refinement approaches into nighttime restoration and enhancement. This comparative literary analysis identified the research gap fields to explore future research directions in nighttime visual enhancement techniques. Finally, we discussed various open issues and future directions in the context enhancement based nighttime enhancement research.
8 citations
TL;DR: It can be inferred from comparative analysis with respect to other conventional methods that while the algorithm is observed to work well in all three hybrid domains, the SV-DCT domain performs better in terms of iteration count, while DCT-DWT is found to outperform others in Terms of perceptual quality.
Abstract: This paper aims to present an analysis of a noise-aided contrast enhancement algorithm in hybrid transform domains. The performance of our earlier noise-enhanced iterative algorithm, formulated from the motion dynamics of a double-well system exhibiting dynamic stochastic resonance, has been investigated here on hybrid coefficients, viz. singular values (SVs) of wavelet coefficients, SVs of discrete cosine transform (DCT) coefficients, and DCT of wavelet coefficients, of a dark image. The performance of the algorithm is gauged using metrics indicating relative contrast enhancement and perceptual quality. Colorfulness, subjective visual scores and logarithmic contrast metrics for outputs are also observed. Experimental results display noteworthy enhancement of contrast on both natural and synthetically-darkened images. It can be inferred from comparative analysis with respect to other conventional methods that while the algorithm is observed to work well in all three hybrid domains, the SV-DCT domain performs better in terms of iteration count, while DCT-DWT is found to outperform others in terms of perceptual quality.
4 citations
References
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TL;DR: An image enhancement algorithm for images compressed using the JPEG standard is presented, based on a contrast measure defined within the discrete cosine transform (DCT) domain that does not affect the compressibility of the original image.
Abstract: An image enhancement algorithm for images compressed using the JPEG standard is presented. The algorithm is based on a contrast measure defined within the discrete cosine transform (DCT) domain. The advantages of the psychophysically motivated algorithm are 1) the algorithm does not affect the compressibility of the original image because it enhances the images in the decompression stage and 2) the approach is characterized by low computational complexity. The proposed algorithm is applicable to any DCT-based image compression standard, such as JPEG, MPEG 2, and H. 261.
317 citations
"Noise-enhanced contrast stretching ..." refers background or methods in this paper
...Many algorithms reported in literature have been designed for both colored and grayscale images in block DCT domain [18], [19], [10]....
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...Comparative analysis with non-SR-based techniques, like contrast limited adaptive histogram equalization (CLAHE) [13], gamma correction (Gamma), single-scale retinex (Retinex) [14], multi-scale retinex (MSR) [15], and modified high-pass filtering (MHPF) [16], alpha rooting (AR) [17], multicontrast enhancement (MCE) [18], MCE with dynamic-range compression (MCE-DRC) [29], and color enhancement using scaling (CES) [19] has been performed....
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TL;DR: In this letter, a new satellite image contrast enhancement technique based on the discrete wavelet transform (DWT) and singular value decomposition has been proposed and it reconstructs the enhanced image by applying inverse DWT.
Abstract: In this letter, a new satellite image contrast enhancement technique based on the discrete wavelet transform (DWT) and singular value decomposition has been proposed. The technique decomposes the input image into the four frequency subbands by using DWT and estimates the singular value matrix of the low-low subband image, and, then, it reconstructs the enhanced image by applying inverse DWT. The technique is compared with conventional image equalization techniques such as standard general histogram equalization and local histogram equalization, as well as state-of-the-art techniques such as brightness preserving dynamic histogram equalization and singular value equalization. The experimental results show the superiority of the proposed method over conventional and state-of-the-art techniques.
310 citations
"Noise-enhanced contrast stretching ..." refers background in this paper
...Hybrid domains like SVD-DWT have been explored by [20], [21] where the broad mechanism adopted is the equalization of singular values (of image or approximation band) by a coefficient found by ratio of largest singular values of the image and an equalized image....
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TL;DR: The proposed technique, computationally more efficient than the spatial domain based method, is found to provide better enhancement compared to other compressed domain based approaches.
Abstract: This paper presents a new technique for color enhancement in the compressed domain. The proposed technique is simple but more effective than some of the existing techniques reported earlier. The novelty lies in this case in its treatment of the chromatic components, while previous techniques treated only the luminance component. The results of all previous techniques along with that of the proposed one are compared with respect to those obtained by applying a spatial domain color enhancement technique that appears to provide very good enhancement. The proposed technique, computationally more efficient than the spatial domain based method, is found to provide better enhancement compared to other compressed domain based approaches.
238 citations
"Noise-enhanced contrast stretching ..." refers background or methods in this paper
...Many algorithms reported in literature have been designed for both colored and grayscale images in block DCT domain [18], [19], [10]....
[...]
...Comparative analysis with non-SR-based techniques, like contrast limited adaptive histogram equalization (CLAHE) [13], gamma correction (Gamma), single-scale retinex (Retinex) [14], multi-scale retinex (MSR) [15], and modified high-pass filtering (MHPF) [16], alpha rooting (AR) [17], multicontrast enhancement (MCE) [18], MCE with dynamic-range compression (MCE-DRC) [29], and color enhancement using scaling (CES) [19] has been performed....
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...According to [19], PQM should be close to 10 for good perceptual quality (digression away from 10 on either direction is an indication on decrease in perceptual quality)....
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TL;DR: In this article, an amplification of random perturbations by the interaction of nonlinearities internal to the climatic system with external, orbital forcing is found, and this stochastic resonance is investigated in a highly simplified, zero-dimensional climate model.
Abstract: An amplification of random perturbations by the interaction of non-linearities internal to the climatic system with external, orbital forcing is found. This stochastic resonance is investigated in a highly simplified, zero-dimensional climate model. It is conceivable that this new type of resonance might play a role in explaining the 10 5 year peak in the power spectra of paleoclimatic records. DOI: 10.1111/j.2153-3490.1982.tb01787.x
179 citations
TL;DR: The main advantage of the proposed algorithm enhances the details in the dark and the bright areas with low computations without boosting noise information and affecting the compressibility of the original image since it performs on the images in the compressed domain.
Abstract: The object of this paper is to present a simple and efficient algorithm for dynamic range compression and contrast enhancement of digital images under the noisy environment in the compressed domain. First, an image is separated into illumination and reflectance components. Next, the illumination component is manipulated adaptively for image dynamics by using a new content measure. Then, the reflectance component based on the measure of the spectral contents of the image is manipulated for image contrast. The spectral content measure is computed from the energy distribution across different spectral bands in a discrete cosine transform (DCT) block. The proposed approach also introduces a simple scheme for estimating and reducing noise information directly in the DCT domain. The main advantage of the proposed algorithm enhances the details in the dark and the bright areas with low computations without boosting noise information and affecting the compressibility of the original image since it performs on the images in the compressed domain. In order to evaluate the proposed scheme, several base-line approaches are described and compared using enhancement quality measures
143 citations
"Noise-enhanced contrast stretching ..." refers methods in this paper
...Comparative analysis with non-SR-based techniques, like contrast limited adaptive histogram equalization (CLAHE) [13], gamma correction (Gamma), single-scale retinex (Retinex) [14], multi-scale retinex (MSR) [15], and modified high-pass filtering (MHPF) [16], alpha rooting (AR) [17], multicontrast enhancement (MCE) [18], MCE with dynamic-range compression (MCE-DRC) [29], and color enhancement using scaling (CES) [19] has been performed....
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