Objective image and video quality metrics focus mostly on the digital representation of the signal. However, the display characteristics are also essential for the overall Quality of Experience (QoE). In this paper, w...
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ISBN:
(纸本)9781479902880
Objective image and video quality metrics focus mostly on the digital representation of the signal. However, the display characteristics are also essential for the overall Quality of Experience (QoE). In this paper, we use a model of a backlight dimming system for Liquid Crystal Display (LCD) and show how the modeled image can be used as an input to quality assessment algorithms. For quality assessment, we propose an image quality metric, based on Peak Signal-to-Noise Ratio (PSNR) computation in the CIE L*a*b* color space. The metric takes luminance reduction, color distortion and loss of uniformity in the resulting image in consideration. Subjective evaluations of images generated using different backlight dimming algorithms and clipping strategies show that the proposed metric estimates the perceived image quality more accurately than conventional PSNR.
Single image super-resolution (SR) is a severely unconstrained task. While the self-example-based methods are able to reproduce sharp edges, they perform poorly for textures. For recovering the fine details, higher-le...
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ISBN:
(纸本)9781479902880
Single image super-resolution (SR) is a severely unconstrained task. While the self-example-based methods are able to reproduce sharp edges, they perform poorly for textures. For recovering the fine details, higher-level image segmentation and corresponding external texture database are employed in the example-based SR methods, but they involve too much human interaction. In this paper, we discuss the existing problems of example-based technique using scale space analysis. Accordingly, a robust pixel classification method is designed based on the phase congruency model in scale space, which can effectively divide images into edges, textures and flat regions. Then a super-resolution framework is proposed, which can adaptively emphasize the importance of high-frequency residuals in structural examples and scale invariant fractal property in textural regions. Experimental results show that our SR approach is able to present both sharp edges and vivid textures with few artifacts.
The new ISO/ITU-T standard for still image coding, JPEG2000, has been shown to provide superior coding efficiency to the previous standard, JPEG. Because of the superb performance of JPEG2000. it is reasonable to argu...
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ISBN:
(纸本)0819444111
The new ISO/ITU-T standard for still image coding, JPEG2000, has been shown to provide superior coding efficiency to the previous standard, JPEG. Because of the superb performance of JPEG2000. it is reasonable to argue that Motion-JPEG2000, the corresponding moving picture coding standard of JPEG2000, has equally outstanding performance. However, there has not been a sufficient performance evaluation of Motion-JPEG2000. To this end, we have studied the potential of Motion-JPEG2000 for video processing. Our experiments show that Motion-JPEG2000 provides high compression performance, strong error resilience, and good perceptual image quality. Together with a rich set of features inherited from JPEG2000, Motion-JPEG2000 has advantages as a coding standard for video processing in many applications.
Predicting/estimating the 6DoF pose parameters for multi-instance objects accurately in a fast manner is an important issue in robotic and computer vision. Even though some bottom-up methods have been proposed to be a...
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ISBN:
(纸本)9781728185514
Predicting/estimating the 6DoF pose parameters for multi-instance objects accurately in a fast manner is an important issue in robotic and computer vision. Even though some bottom-up methods have been proposed to be able to estimate multiple instance poses simultaneously, their accuracy cannot be considered as good enough when compared to other state-of-the-art top-down methods. Their processing speed still cannot respond to practical applications. In this paper, we present a faster and finer bottom-up approach of deep convolutional neural network to estimate poses of the object pool even multiple instances of the same object category present high occlusion/overlapping. Several techniques such as prediction of semantic segmentation map, multiple keypoint vector field, and 3D coordinate map, and diagonal graph clustering are proposed and combined to achieve the purpose. Experimental results and ablation studies show that the proposed system can achieve comparable accuracy at a speed of 24.7 frames per second for up to 7 objects by evaluation on the well-known Occlusion LINEMOD dataset.
visual hyperacuity is the capability of the human eye to see beyond the acuity defined by the number and size of its photo receptors. Optical imaging systems suffer from diffraction since light passes through an apert...
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ISBN:
(纸本)9789536037728
visual hyperacuity is the capability of the human eye to see beyond the acuity defined by the number and size of its photo receptors. Optical imaging systems suffer from diffraction since light passes through an aperture and a lens system. Common diffraction-limited devices are designed to limit this effect and capture a sharp image. Nevertheless, the human eye produces a noteworthy diffraction effect which exceeds these limits, projecting a blurred image over the retina, where photo receptors are located. On this basis, it seems difficult to understand it operating as a diffraction-limited system. Assuming that diffraction could be helpful to achieve visual hyperacuity, we present a method that intend to simulate and explain it: introducing a controlled diffraction, we are able to enhance the image resolution using post-processing techniques as interpolation and inverse filtering. Our approach uses diffraction to improve image resolution when captured with a reduced number of sensors, far from being a limiting factor.
Popular press and congressional record report a belief by the intelligence community that Al Qaeda members communicate through messages embedded invisibly in images shared via the Internet This is certainly plausible ...
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Popular press and congressional record report a belief by the intelligence community that Al Qaeda members communicate through messages embedded invisibly in images shared via the Internet This is certainly plausible as steganography has a rich history of military and civilian use. Current signature-based approaches for detecting the presence of hidden messages rely on discerning "footprints" of steganographic tools. Of greater recent concern is detecting the use of novel tools for which no signature has been established. This research addresses this concern by using a method for detecting anomalies in seemingly innocuous images, applying a genetic algorithm within a computational immune system to leverage powerful imageprocessing through wavelet analysis. The sensors developed with this system demonstrated a surprising level of capability to detect the use of steganographic tools for which the system had no previous exposure, including one tool designed to be statistically stealthy. (C) 2004 SPIE and IST.
Simple and effective image quality assessment (IQA) method is very desirable in many image and video processing applications, such as coding, transmission, restoration and enhancement. Classic pixel absolute error bas...
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ISBN:
(纸本)9781479973392
Simple and effective image quality assessment (IQA) method is very desirable in many image and video processing applications, such as coding, transmission, restoration and enhancement. Classic pixel absolute error based objective IQA metrics such as mean square error (MSE) and corresponding peak signal to noise ratio (PSNR) are widely used for various applications due to low computation and clear physical meanings, but have also been criticized for poorly correlated with subjective evaluation. Inspired by that human visual system (HVS) is more sensitive to image local edge distortion than flat or texture areas, in this paper, we propose a novel edge enhanced MSE (EE-MSE) to emphasize edge distortion effects on IQA. Experimental results on LIVE database release 2 show that the proposed EE-MSE IQA metric is competitive with state-of-the-art HVS-based IQA metrics, while has lower computational complexity and is more suitable for optimization task.
This paper deals with the joint use of connected operators and image inpainting for image filtering. Connected operators filter the image by merging its flat zones while preserving contour information. image inpaintin...
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ISBN:
(纸本)9780819466211
This paper deals with the joint use of connected operators and image inpainting for image filtering. Connected operators filter the image by merging its flat zones while preserving contour information. image inpainting restores the values of an image for a destroyed or consciously masked subregion of the image domain. In the present paper, it will be shown that image inpainting can be combined with connected operators to perform an efficient geometrical filtering technique. First, connected operators are presented and their drawbacks for certain applications are highlighted. Second, image inpainting methodology is introduced and a structural image inpainting algorithm is described. Finally, a general filtering scheme is proposed to show how the drawbacks of connected operators can be efficiently solved by structural image inpainting.
In this paper, the authors propose a new procedure for copyright protection by using a bio-inspired wavelet based data hiding approach. The proposed method takes advantage of Human visual System (HVS) characteristics ...
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ISBN:
(纸本)9781424412358
In this paper, the authors propose a new procedure for copyright protection by using a bio-inspired wavelet based data hiding approach. The proposed method takes advantage of Human visual System (HVS) characteristics to provide better watermarked image quality. It also exploits visual Secret Sharing (VSS) technique to guarantee the security of the procedure. Performance improvement with respect to the existing algorithms is obtained by Particle Swarm Optimization (PSO).
image noise level estimation is an important step in many imageprocessing tasks such as denoising, compression and segmentation. Although recently proposed SVD and PCA approaches have produced the most accurate estim...
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ISBN:
(纸本)9781479961399
image noise level estimation is an important step in many imageprocessing tasks such as denoising, compression and segmentation. Although recently proposed SVD and PCA approaches have produced the most accurate estimates so far, these linear subspace-based methods still suffer from signal contamination from the clean signal content, especially in the low noise situation. In addition, the common performance evaluation procedure currently in use treats test images as noise-free. This omits the noise already in those test images and invariably incurs a bias. In this paper we make two contributions. First, we propose a new noise level estimation method using nonlinear local surface approximation. In this method, we first approximate image noise-free content in each block using a high degree polynomial. Then the block residual variances, which follow chi squared distribution, are sorted and the upper quantile of a carefully chosen size is used for estimation. Secondly, we propose a new performance evaluation procedure that is free from the influence of the noise already present in the test images. Experimental results show that it has much improved performance than typical state-of-the-art methods in terms of both estimation accuracy and stability.
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