HVS-Aware Dynamic Backlight Scaling in TFT-LCDs

Most distortion/artifacts in low bit-rate compressed videos are strong and obvious to human eyes, and may even change the spatio-temporal structure of visual objects. Therefore it is important to evaluate the compound perceptual impact of spatial and temporal changes. Recent neurophysiological researches have found that the high-level spatial information (shape and depth, etc.) and temporal information (motion, etc.) are processed separately in two visual pathways in human brains. In this paper, spatial and temporal distortions are evaluated separately in two modules, and are then combined in an integration module. Two subjective viewing experiments are performed. One experiment is to evaluate the subjective quality on temporal distortion only, and second experiment is to evaluate the low bit-rate videos with both spatial and temporal distortions. Experimental results and the associated analysis show that the proposed visual quality metric is in good alignment with human perception

The aim of this study was to investigate the spatial and temporal distortions that occur in strabismic and anisometropic amblyopic vision. Twelve subjects with strabismic (n = 4), anisometropic (n = 4), mixed amblyopia (n = 3) and bilateral refractive amblyopia (n = 1) were asked to describe and sketch their subjective percept of different geometrical patterns, as seen with their amblyopic eye. Based on their descriptions, computer-animated patterns were generated, which were then validated by the subjects. Both spatial distortions and temporal instability were perceived mainly by strabismic and strabismic-anisometropic amblyopes. Temporal instability occurred mainly at high spatial frequencies. Our data suggest that strabismus, in addition to amblyopia, is needed to elicit significant spatial and temporal distortions. The occurrence of these distortions may be related to the early history of each subject.

We report on the development of an automated visual inspection system for liquid crystal display (LCD) modules. The system comprises a highly graphical software program, a unique image processing algorithm, a PC interface card for driving different types of LCD modules, and a universal test jig for holding these modules. The system is able to detect faulty or malfunctioning LCD modules with minimum intervention from human operator; allows testing to be carried out for evaluating the display quality such as contrast ratio; is able to create new test databases for new LCD modules; allows permanent storage/backup of test databases for each individual LCD module; and provides a friendly user interface for ease of operation. In addition, the system has the following features: different access levels for different users; an editor for creating software drivers for driving different types of LCD modules; and a graphical help facility.

Steganography is the method of providing Computer security in which hiding the required information is done by inserting messages within other messages, which is a string of characters containing the useful information, in a carrier image. Using this technique, the required information from the secret image is embedded into individual rows as well as columns present in the pixels of carrier image. In this paper, a novel fuzzy logic based technique is proposed to hide the secret message in individual rows and in individual columns of pixels of the carrier image and to extract the hidden message in the same carrier image. The fuzzification process transforms the image in to various bitplanes. Pixel number and Correlation Value is computed in the original image for hiding the secret information in to the original image. The pixel number and Correlation value is also used as the key for retrieving the embedded image from the receiver side. Pixel merging is done in the sender side by assigning a steganographic value of white and black pixels in original image based on the fuzzy rules by comparing the pixels present in the original and secret images. The information which is hided can be retrieved by using the same fuzzy rules. Experimental results show that the proposed method can hide and retrieve the secret and important messages in an image more effectively and accurately.

While subjective assessment is recognized as the most reliable means of quantifying video quality, objective assessment has proven to be a desirable alternative. Existing video quality indices achieve reasonable prediction of human quality scores, and are able to well predict quality degradation due to spatial distortions but not so well those due to temporal distortions. In this paper, we propose a perception-based quality index in which the novelty is the direct use of motion information to extract temporal distortions and to model the human visual attention. Temporal distortions are computed from optical flow and common vector metrics. Results of psychovisual experiments are used for modeling the human visual attention. Results show that the proposed index is competitive with current quality indices presented in the state of art. Additionally, the proposed index is much faster than other indices also\nincluding a temporal distortion measure.

The Liquid Crystal Display provides a necessary information interface to pilots from their aircraft and equipment. In order to successfully complete mission requirements, increased amounts of information are made available to pilots. The control of commercial and military air transports, weapons systems and ordinance that contain the highest technology electronics requires pilots to have instant access to large amounts of data. Mechanical dials and 'steam gauges' alone do not have the capability to provide that data. Operational readiness comes with a need for all display systems to have the utmost availability, reliability and maintainability. Original specifications developed from the initial use of smaller fixed format liquid crystal displays have been reproduced over the years with little specification maintenance or attention to actual environmental demands that may or may not have been apparent with mechanical dials (white paint on black dials). As the Liquid Crystal Display grows increasingly important in the aircraft, the need for improved reliability increases. The examples that follow will suggest that further definition is needed on exactly how and where the displays are to be used, and in what environments they will be required to survive. With cooperative efforts of among equipment designers, display designers, and specification writers, new and updated specifications targeted directly for liquid crystal display systems will help to achieve cost effective, high reliability information display systems for users.

To test the theory of gravity one needs to test, on one hand, how space and time are distorted by matter, and on the other hand, how matter moves in a distorted space–time. Current observations provide tight constraints on the motion of matter, through the so-called redshift-space distortions, but they only provide a measurement of the sum of the spatial and temporal distortions, via gravitational lensing. In this letter, we develop a method to measure the time distortion on its own. We show that the coming generation of galaxy surveys, like the Square Kilometre Array, will allow us to measure the distortion of time with an accuracy of 10–30 per cent. Such a measurement will be essential to test deviations from the ΛCDM model in a fully model-independent way. In particular, it can be used to compare the spatial and temporal distortions of space–time and to unambiguously distinguish between modifications of gravity and dark fifth forces acting on dark matter.

The political economy of pollution markets: Historical lessons for modern energy and climate planners

A method to maximize backlight dimming of liquid crystal displays (LCDs) based on human visual system are proposed to minimize power consumption of display panels. Based on images, the proposed method optimizes global, local, and red, green, blue (RGB) backlight dimming by enhancing dimming about 12% on average for various images while maintaining tolerable degradation of perceived image qualities in pixel saturation areas. The method considers and utilizes the brightness sensitivity and contrast response functions of human visual system using the mean luminance and the contrast of an image, which are mathematically modelled to allow optimization for display panels and application areas. A simulator that can calculate various dimming cases with the evaluations of numerical and perceptual image qualities as well as power consumption amount is introduced. With pattern and real photo images, the degree of power savings and the preservation of image quality of the proposed method are verified to outperform conventional approaches with high scores of the mean opinion score (MOS) and the structural similarity index measure (SSIM) over 0.97 while saving more than 10% of power dissipation.

This paper proposes a dynamic global backlight dimming algorithm based on the analysis of the cumulative distribution function (CDF) of the image histogram. For each intensity level, the convexity of the CDF is calculated using the distance to the uniform histogram curve. Using these values, the proposed algorithm characterizes the shape of the CDF to find the proper clipping ratio. This ratio enables to get the maximum level data beyond which the intensity levels are clipped, as the results of backlight dimming but image distortion. The experimental results show that the proposed algorithm gives a good compromise between backlight power reduction and image quality preservation, quantified by the PSNR metric.

Reversible watermarking has drawn extensive attentions in recent years due to its broad applications of digital forensics and data security. This paper proposes a novel reversible watermarking approach, which has the perfect reversibility of the embedded data and the original image. In order to increase the embedding capacity, the proposed approach utilizes the enhanced local prediction to reduce the prediction error of every pixel value. Different from traditional reversible watermarking algorithms considering all the image pixels equivalently before prediction, an enhanced image is first computed by multiplying the original image with its saliency map. By linearly formulating each pixel value in an original image as a weighted sum of the enhanced pixel values in its local neighborhood, the correlation coefficients as learned weights are then solved as a least squares solution. Based on two state-of-the-art datasets, the experimental results show that the proposed approach achieves large embedding capacity with relatively low visual distortion.

Motion silencing of flicker distortions on naturalistic videos

An algorithm of dynamic watermark based on neural network is presented which is more robust against attack of false authentication and watermark-tampered operations contrasting with one watermark embedded method. (1) Five binary images used as watermarks are coded into a binary array. The total number of 0s and 1s is 5*N, every 0 or 1 is enlarged fivefold by information-enlarged technique. N is the original total number of the watermarks' binary bits. (2) Choose the seed image pixel p_x,y and its 3&times;3 vicinities pixel p _x-1,y-1,p_x-1,y,p_x-1,y+1,p_x,y-1,p_x,y+1,p_x+1,y-1,p_x+1,y,p_x+1,y+1 as one sample space. The p_x,y is used as the neural network target and the other eight pixel values are used as neural network inputs. (3) To make the neural network learn the sample space, 5*N pixel values and their closely relevant pixel values are randomly chosen with a password from a color BMP format image and used to train the neural network.(4) A four-layer neural network is constructed to describe the nonlinear mapped relationship between inputs and outputs. (5) One bit from the array is embedded by adjusting the polarity between a chosen pixel value and the output value of the model. (6) One randomizer generates a number to ascertain the counts of watermarks for retrieving. The randomly ascertained watermarks can be retrieved by using the restored neural network outputs value, the corresponding image pixels value, and the restore function without knowing the original image and watermarks (The restored <i>coded-watermark</i>_bit=1, if <i>ox,y(restored)</i>&gt;p_x,y(<i>reconstructed, else coded-watermark_bit </i>=0). The retrieved watermarks are different when extracting each time. The proposed technique can offer more watermarking proofs than one watermark embedded algorithm. Experimental results show that the proposed technique is very robust against some image processing operations and JPEG lossy compression. Therefore, the algorithm can be used to protect the copyright of one important image.

Prediction of pleural invasion in lung cancer is crucial in planning appropriate operating procedures and can be assessed using dynamic chest radiography (DCR). However, this assessment is negatively affected by rib shadows in conventional images. The purpose of this study was to develop a deep learning-based bone suppression technique for DCR in various projection directions. Twenty breathing XCAT phantoms with lung tumors and a pair of phantoms consisting only of bone structures were generated. The XCAT phantoms were virtually projected from six directions, resulting in 54000 multidirectional chest X-ray images and were used for training a pix2pix model to estimate bone images from original images. Bone suppression (BS) images were created by subtracting the bone images from the original images and then evaluated based on the peak signal to noise ratio (PSNR), structural similarity index measure (SSIM), and Fréchet Video Distance (FVD). Clinical cases were processed using the trained model as well. Furthermore, lung tumors on the original and BS images were tracked using OpenCV template matching, and the tracking accuracy was compared. The PSNR, SSIM, and FVD were 0.9966, 52.20 and 136.9, respectively. In the visual evaluation, we confirmed the effect of BS without temporal fluctuation of pixel values in both the resulting images of the XCAT phantom and real patients. Furthermore, precise tracking of the targeted tumor was achieved on the resulting BS images even in oblique directions, without any interruption from the rib shadows. These results indicate that our proposed method can effectively reduce bone shadows as well as temporal variations in the effect of bone suppression.

Widely considered to be the best Surrealist poet writing in Catalan, J. V. Foix incorporated a number of principles associated with Sigmund Freud into his imaginative works, in which an assortment of dream mechanisms expressed his unconscious desires, fears, thoughts, and motivations. By means of surprising associations and astonishing encounters, Foix managed to transform his everyday surroundings into a magical universe characterized by whimsical juxtapositions, impossible encounters, and unexpected discoveries. Extending from the beginning to the end of his long and distinguished career, the four poems that I have chosen to examine illustrate the characteristic manner in which he juxtaposed spatial and temporal distortions in the process of crafting his unforgettable dream-works.