Showing papers in "IEEE Transactions on Consumer Electronics in 2008"

Recursively separated and weighted histogram equalization for brightness preservation and contrast enhancement

Abstract: This paper proposes a new histogram equalization method, called RSWHE (recursively separated and weighted histogram equalization), for brightness preservation and image contrast enhancement. The essential idea of RSWHE is to segment an input histogram into two or more sub-histograms recursively, to modify the sub-histograms by means of a weighting process based on a normalized power law function, and to perform histogram equalization on the weighted sub-histograms independently. RSIHE (recursive sub-image histogram equalization) and RMSHE (recursive mean separate histogram equalization) are some methods similar to RSWHE, but they do not carry out the above weighting process. We show that compared to other existent methods, RSWHE preserves the image brightness more accurately and produces images with better contrast enhancement.

Vision-based location positioning using augmented reality for indoor navigation

Abstract: In this paper, we propose a vision-based location positioning system using augmented reality technique for indoor navigation. The proposed system automatically recognizes a location from image sequences taken of indoor environments, and it realizes augmented reality by seamlessly overlaying the user's view with location information. To recognize a location, we pre-constructed an image database and location model, which consists of locations and paths between locations, of an indoor environment. Location is recognized by using prior knowledge about the layout of the indoor environment. The image sequence is obtained by a wearable mobile PC with camera, which transmits the images to remote PCs for processing. The remote PCs perform marker detection, image sequence matching, and location recognition. The remote PCs transmit the recognized location information to the wearable mobile PC. The system provides the ability to identify similar locations in the image database and display location-related information. Accurate and efficient location positioning is achieved by using several vision-based techniques. The proposed system was tested in an indoor environment and achieved an average location recognition success rate of 89%. The proposed system could be applied to various consumer applications including the door plate system, notice board system, shopping assistance system, and bus service route guide system, among others1.

Simple adaptive median filter for the removal of impulse noise from highly corrupted images

Abstract: This paper presents a simple, yet efficient way to remove impulse noise from digital images. This novel method comprises two stages. The first stage is to detect the impulse noise in the image. In this stage, based on only the intensity values, the pixels are roughly divided into two classes, which are "noise-free pixel" and "noise pixel". Then, the second stage is to eliminate the impulse noise from the image. In this stage, only the "noise-pixels" are processed. The "noise-free pixels " are copied directly to the output image. The method adaptively changes the size of the median filter based on the number of the "noise-free pixels " in the neighborhood. For the filtering, only "noise-free pixels " are considered for the finding of the median value. The results from 100 test images showed that this proposed method surpasses some of the state-ofart methods, and can remove the noise from highly corrupted images, up to noise percentage of 95%. Average processing time needed to completely process images of 1600times1200 pixels with 95% noise percentage is less than 2.7 seconds. Because of its simplicity, this proposed method is suitable to be implemented in consumer electronics products such as digital television, or digital camera.

Adaptive contrast enhancement using gain-controllable clipped histogram equalization

Abstract: Histogram equalization is a simple and effective method for contrast enhancement as it can automatically define the intensity transformation function based on statistical characteristics of the image. However, it tends to alter the brightness of the entire image, which it is not suitable for consumer electronic products, where preservation of the original brightness is essential to avoid annoying artifacts. This paper presents a new contrast enhancement method for generalization of the existing bihistogram equalization (BHE) and recursive mean-separate histogram equalization (RMSHE) methods. The proposed method is referred to gain-controllable clipped histogram equalization (GC-CHE) to provide both histogram equalization and brightness preservation. More specifically adaptive contrast enhancement is realized by using clipped histogram equalization with controllable gain. The clipping rate is determined based on the mean brightness, and the clipping threshold is determined based on the clipping rate. The clipping rate is adaptively controlled to enhance the contrast with preserving the mean brightness. It is mathematically proven that the mean brightness of the output image converges to that of the input image with adaptive controlled. Simulation results show that the proposed GC-CHE method outperforms existing histogram-based methods, such as HE, BHE, and RMSHE, in various situations.

Quality analysis for 3D video using 2D video quality models

Abstract: The 3D (3-dimensional) video technologies are emerging to provide more immersive media content compared to conventional 2D (2-dimensional) video applications. More often 3D video quality is measured using rigorous and time-consuming subjective evaluation test campaigns. This is due to the fact that 3D video quality can be described as a combination of several perceptual attributes such as overall image quality, perceived depth, presence, naturalness and eye strain, etc. Hence this paper investigates the relationship between subjective quality measures and several objective quality measures like PSNR, SSIM, and VQM for 3D video content. The 3D video content captured using both stereo camera pair (two cameras for left and right views) and colour-and-depth special range cameras are considered in this study. The results show that, VQM quality measures of individual left and right views (rendered left and right views for colour-and-depth sequences) can be effectively used in predicting the overall image quality and statistical measures like PSNR and SSIM of left and right views illustrate good correlations with depth perception of 3D video.

Salt-and-pepper noise detection and reduction using fuzzy switching median filter

Abstract: This paper presents a new fuzzy switching median (FSM) filter employing fuzzy techniques in image processing. The proposed filter is able to remove salt-and-pepper noise in digital images while preserving image details and textures very well. By incorporating fuzzy reasoning in correcting the detected noisy pixel, the low complexity FSM filter is able to outperform some well known existing salt-and-pepper noise fuzzy and classical filters.

LRU-WSR: integration of LRU and writes sequence reordering for flash memory

Abstract: Most mobile devices are equipped with a NAND flash memory even if it has characteristics of not-in-place update and asymmetric I/O latencies among read, write, and erase operations: write/erase operations are much slower than a read operation in a flash memory. For the overall performance of a flash memory system, the buffer replacement policy should consider the above severely asymmetric I/O latencies. However, existing LRU buffer replacement algorithm cannot deal with the above problem. This paper proposes the LRU-WSR buffer replacement algorithm that enhances LRU by reordering writes of not-cold dirty pages from the buffer cache to flash storage. The enhanced LRU-WSR algorithm focuses on reducing the number of write/erase operations as well as preventing serious degradation of buffer hit ratio. The experimental results show that the LRU-WSR outperforms other algorithms including LRU, CF-LRU, and FAB1.

Design and implementation of intelligent home control systems based on active sensor networks

Abstract: The ubiquitous home network has gained widespread attentions due to its seamless integration into everyday life. This innovative system transparently unifies various home appliances, smart sensors/actuators and wireless communication technologies. The ubiquitous home network gradually forms a complex system to process various tasks. Developing this trend, we suggest a new intelligent home control system based on a wireless sensor/actuator network (we call it as an "Active sensor network"). The proposed intelligent home control system divides and assigns various home network tasks to appropriate components. It can integrate diversified physical sensing information and control various consumer home devices, with the support of active sensor networks having both sensor and actuator components. We develop a new routing protocol LQIR (Link Quality Indicator based Routing) to improve the performance of our active sensor networks. This paper introduces the proposed home control system's design that provides intelligent services for users. We demonstrate its implementation using a real testbed.

Automatic room light intensity detection and control using a microprocessor and light sensors

Abstract: In this paper we propose a design using both a microprocessor and light sensors for automatic room light detection and control. Our design, the HLCM (home light control module) which will be installed in every light fixture of a family, is made up of four blocks: the pyroelectric infrared (PIR) sensor circuit, the light sensor circuit, the microprocessor and the RF module. By using the PIR sensor circuit, the HLCM detects if a human body enters the detection area or not. If there is no human body present, all controlled lights are turned off. If there is, the HLCM detects the light intensity under the environment and maintains sufficient light by controlling the number of lights. We have also integrated an RF module to transmit and receive the data from each HLCM so we can control different lights in different regions. The result of using the HLCM shows that the total power consumption can be reduced.

A low cost GSM/GPRS based wireless home security system

Abstract: Home security system is needed for occupants' convenience and safety. In this paper, we present the design and implementation of a low cost, low power consumption, and GSM/GPRS (global system for mobile communication /general packet radio service) based wireless home security system. The system is a wireless home network which contains a GSM/GPRS gateway and three kinds of wireless security sensor nodes that are door security nodes, infrared security nodes and fire alarm nodes. The nodes are easy installing. The system can response rapidly to alarm incidents and has a friendly user interface including a LCD (liquid crystal display) and a capacitive sensor keyboard. The wireless communication protocol between the gateway and the nodes is also suitable for other home appliances. Furthermore, some methods are taken to ensure the security of system information.

Statistical models of appearance for eye tracking and eye-blink detection and measurement

Abstract: A statistical active appearance model (AAM) is developed to track and detect eye blinking. The model has been designed to be robust to variations of head pose or gaze. In particular we analyze and determine the model parameters which encode the variations caused by blinking. This global model is further extended using a series of sub-models to enable independent modeling and tracking of the two eye regions. Several methods to enable measurement and detection of eye-blink are proposed and evaluated. The results of various tests on different image databases are presented to validate each model.

Backlight power reduction and image contrast enhancement using adaptive dimming for global backlight applications

Abstract: The paper presents an adaptive dimming technique to reduce backlight power consumption and enhance image contrast for global backlight applications. The proposed adaptive dimming technique consists of two new algorithms: backlight dimming algorithm and contrast enhancement algorithm. The backlight-dimming algorithm obtains appropriate 0% to 50% backlight power reduction depending on characteristics of the image data. The contrast enhancement algorithm not only reduces the adverse effect of backlight power saving, but also improves 20.75% enhancement of image contrast ratio on the average. Numerous simulation results are used for illustration of the effectiveness and merits of the proposed adaptive dimming technique. Experimental results are conducted to show the performance and usefulness of the proposed technique on a 2.2-inch mobile phone liquid crystal display (LCD) made by thin-film-transistor (TFT) technology.

Using active and passive RFID technology to support indoor location-aware systems

Abstract: Emerging mobile technologies are being applied successfully in cultural spaces to help users to get the correct information no matter where he is, in such a way that their use result better than traditional guides. Different technologies (RFID, Wi-Fi, etc.) are applied to allow mobile devices, such as PDAs or smart phones, interact with their environment in order to provide users with updated information regarding his physical location. This paper describes a system environment based on both active and passive RFID technology which supports the automatic positioning of mobile devices in closed spaces. This proposal results especially useful to provide location-aware information avoiding the need for users to manually select the desired information they want to view. This proposal has been successfully proved for the location and positioning of PDAs.

A contrast enhancement method using dynamic range separate histogram equalization

Abstract: In this paper, a contrast enhancement method using dynamic range separate histogram equalization (DRSHE) is proposed. Histogram equalization (HE) method is widely used for contrast enhancement. However, HE is not suitable for consumer electronic products directly because it may cause side-effects such as washed out appearance and false contouring due to the significant change in brightness. DRSHE separates the dynamic range of histogram into k parts and resizes the grayscale range based on its area ratio. Then intensities of histogram are uniformly redistributed in resized grayscale range. DRSHE uses weighted average of absolute color difference (WAAD) in order to emphasize the edge of original image and moderate the histogram variation effectively. We introduced a linear adaptive scale factor to reduce excessive changes in brightness. The experimental results show that DRSHE suppresses unintended changes in brightness and preserves naturalness of the original image compared with conventional methods.

The DOG gateway: enabling ontology-based intelligent domotic environments

Abstract: This paper moves a first step towards the creation of Intelligent Domotic Environments (IDE) in real-life home-living. A new Domotic OSGi Gateway (DOG) is presented, able to manage different domotic networks as a single, technology neutral, home automation system. The adoption of a standard framework such as OSGi, and of sophisticated modeling techniques stemming from the Semantic Web research community, allows DOG to go beyond simple automation and to support reasoning-based intelligence inside home environments. By exploiting automatic device generalization, syntactic and semantic command validation, and internetwork scenario definition, DOG provides the building blocks for supporting the evolution of current, isolated, home automation plants into IDEs, where heterogeneous devices and domotic systems are coordinated to behave as a single, intelligent, proactive system. The paper introduces the DOG architecture and the underlying ontology modeling. A case study is also illustrated, where DOG controls a laboratory reconstruction of a simple domotic environment.

A wireless power outlet system for smart homes

Abstract: This paper presents the design and implementation of a wireless-controllable power outlet system for home automation networks. The proposed power outlet module integrates a ZigBee radio into its architecture. It acts as an actuator node in the home automation networks for remote control operations. A prototype of the power outlet module following the proposed architecture has been implemented. A testbed of a simple home automation network for validating the basic functions of the power outlet module has also been created. Results of the demonstration experiment show that the proposed power outlet module enables easy and flexible control of various home appliances with little infrastructure. It helps us add more intelligence into the home environments rapidly.

Brightness preserving weight clustering histogram equalization

Abstract: Histogram equalization (GHE) is a simple and widely accepted method for contrast enhancement. Although there are extensions of GHE that can preserve the brightness of the original image better than the original method, these extensions sometimes fail to enhance the visualization of the original image. Therefore, we propose a new method called "Brightness Preserving Weight Clustering Histogram Equalization" (BPWCHE) that can simultaneously preserve the brightness of the original image and enhance visualization of the original image. BPWCHE assigns each non-zero bin of the original image's histogram to a separate cluster, and computes each cluster's weight. Then, to reduce the number of clusters, we use three criteria (cluster weight, weight ratio and widths of two neighboring clusters) to merge pairs of neighboring clusters. The clusters acquire the same partitions as the result image histogram. Finally, transformation functions for each cluster's sub-histogram are calculated based on the traditional GHE method in the new acquired partitions of the result image histogram, and the sub-histogram's gray levels are mapped to the result image by the corresponding transformation functions. We showed experimentally that BPWCHE can preserve image brightness and enhance visualization of images more effectively than GHE and other brightness preserving methods.

Contrast enhancement by automatic and parameter-free piecewise linear transformation for color images

Abstract: Conventional contrast enhancement methods have four shortcomings. First, most of them need transformation functions and parameters which are specified manually. Second, most of them are application-oriented methods. Third, most of them are performed on gray level images. Fourth, the histogram equalization (HE) based enhancement methods use non-linear transform function. Thus, this paper proposes an automatic and parameter-free contrast enhancement algorithm for color images. This method includes following steps: First, RGB color space is transformed to HSV color space. Second, image content analysis is used to analyze the image illumination distribution. Third, the original image is enhanced by piecewise linear based enhancement method. Finally, the enhancement image is transformed back to RGB color space. This novel enhancement is automatic and parameter-free. Our experiments included various color images with low and high contrast. Experiment results show that the performance of the proposed method is better than histogram equalization (HE) and its six variations in non-over enhancement and natural clearly revealed. Moreover, the proposed algorithm can be run on an embedded environment (such as mobile device, digital camera, or other consumer products) and processed in real-time system due to its simplicity and efficiently.

Color image enhancement using brightness preserving dynamic histogram equalization

Abstract: Histogram equalization (HE), although one of the most popular techniques used for digital image enhancement, is not very suitable to be implemented directly in consumer electronics, such as television, because this method tends to produce an output with saturation effect. To overcome this weakness, it is suggested that the mean intensity of the input image be maintained in the output image. Previously, we proposed a method known as brightness preserving dynamic histogram equalization (BPDHE) which can fulfill this requirement for grayscale images. In this paper, we present several possibilities to extend this method for color images.

Layer-weighted unequal error protection for scalable video coding extension of H.264/AVC

Abstract: The scalable video coding extension of H.264/AVC is a current standardization project. This paper deals with unequal error protection (UEP) scheme for scalable video bitstream over packet-lossy networks using forward error correction (FEC). The proposed UEP scheme is developed by exploiting jointly the unequal importance existing both in temporal layers and quality layers of hierarchial scalable video bitstream. For efficient assignment of FEC codes, the proposed UEP scheme uses a simple and efficient performance metric, namely layer-weighted expected zone of error propagation (LW-EZEP). The LW-EZEP is adopted for quantifying the error propagation effect on video quality degradation from packet loss in temporal layers and in quality layers. Compared to other UEP schemes, the proposed UEP scheme demonstrates strong robustness and adaptation for variable channel status.

Dynamic load balancing through association control of mobile users in WiFi networks

Abstract: With the development of IEEE 802.11 MAC (medium access control) protocols, efficient utilization of wireless local area networks (WLANs) has become a very important issue. In typical IEEE 802.11 networks, the association between mobile users (MUs) and access point (AP) is based on the signal strength information. As a result, it often results in the extremely unfair bandwidth allocation among MUs. In this paper, we propose a distributed association algorithm to achieve load balancing among the APs. The proposed algorithm gradually balances the AP loads for the available multiple bit rate choices in a distributed manner. We analyze the stability and overhead of the proposed algorithm, and show the improvement of the fairness via computer simulation. Additionally, we have implemented a prototype on a testbed to prove its feasibility.

Digital video stabilization through curve warping techniques

Abstract: The widespread diffusion of hand-held devices with video recording capabilities requires the adoption of reliable digital Stabilization methods to enjoy the acquired sequences without disturbing jerkiness. In order to effectively get rid of the unwanted camera movements, an estimate of the global motion between adjacent frames is necessary. This paper presents a novel approach for estimating the global motion between frames using a curve warping technique known as dynamic time warping. The proposed algorithm guarantees robustness also in presence of sharp illumination changes and moving objects.

Recently-evicted-first buffer replacement policy for flash storage devices

Abstract: Flash memory has been widely used as a storage device for consumer devices. Recently, applications using flash memory are becoming complex and diverse. One of obstacles to its wide use is the slow write performance of flash memory caused by its erase-before-write characteristic. To enhance the write performance, FTL (Flash Translation Layer) generally uses the flash log-buffer, where data is written by the out-of-place scheme. However, current log buffer-based FTL schemes show poor performance for random write requests due to the block thrashing problem and high block associativity. Recently, flash-aware buffer cache management schemes are proposed to solve the block thrashing problem. However, they cannot also eliminate the problem completely. In this paper, we propose a novel flashaware buffer cache replacement policy. The technique selects the victim page to be evicted from buffer cache considering the recent victim page sent to the flash log buffer. Our experimental results show that the proposed technique reduces the flash I/O execution time by up to 30%.

Fine directional de-interlacing algorithm using modified Sobel operation

Abstract: This paper presents an intra field de-interlacing algorithm for spatial edge preserving using the detection of accurate edge direction. Conventional intra field de-interlacing algorithms determine the edge direction at the pixel or half pixel level, so that they can be highly sensitive to noise and lead to image degradation. In this paper, the proposed algorithm first considers the edge tendency in the edge region, and then candidate direction vectors (CDVs) are selected using the modified Sobel operation through the edge tendency. Finally, the CDVs are adaptively applied to interpolate the lost pixel in the edge region. Experimental results show that the proposed algorithm performs well with a variety of still and moving images compared with conventional intra field algorithms in the literature.

Multimodal biometric authentication using teeth image and voice in mobile environment

Abstract: Mobile devices such as smart-phone, PDA and mobile-phone are vulnerable to theft and loss due to their small size and the characteristics of the environments in which they are used. A simple and convenient authentication system is required to protect private information stored in the mobile device. Therefore, we propose a new multimodal biometric authentication approach using teeth image and voice as biometric traits in this paper. The individual matching scores obtained from the teeth image and voice are combined using a weighted-summation operation, and the fused-score is utilized to classify an unknown user into the acceptance or rejection. The proposed method is evaluated using 1000 teeth images and voices, in which these are collected by smart-phone, i.e., one mobile device for 50 subjects. In the experiment results, the proposed method has an EER of 2.13%, and we demonstrate the effectiveness of the proposed method.

Information fusion based smart home control system and its application

Abstract: This paper presents an information fusion based smart home control system. The proposed control framework includes an Internet access and information acquisition module, in-house networking services with Bluetooth wireless connectivity, an information fusion based controller using fuzzy logic and fuzzy neural network, and embedded computational units in home appliances. It integrates information from multiple sources to control home appliances to create the smart home environment. The detailed description of the proposed system, from design to implementation, is given in this paper.

System architecture for free-viewpoint video and 3D-TV

Abstract: This paper presents a system architecture of an acquisition, compression and rendering system for 3D- TV and free-viewpoint video applications. We show that the proposed system yields two distinct advantages. First, it achieves an efficient compression of 3D/multi-view video by extending a standard H.264 encoder such that near backward compatibility is retained. Second, the proposed system can efficiently compress both 3D-TV and free- viewpoint multi-view video datasets using the single proposed system architecture.

Multiframe-based bilateral motion estimation with emphasis on stationary caption processing for frame rate up-conversion

Abstract: In this paper, we present a new motion compensated frame rate up-conversion algorithm that uses multiframes to enhance the accuracy of motion estimation We also develop adaptive motion vector smoothing to correct outliers in a motion vector field In addition, stationary caption processing is carried out for removing block artifacts from stationary captions Finally, we propose adaptive-weighted bidirectional motion compensated interpolation to reduce object blurring In experiments using benchmark test sequences, the proposed algorithm improves the average PSNR of interpolated frames by up to 534 dB compared to the conventional algorithm

Fast disparity and motion estimation based on correlations for multiview video coding

Abstract: Recently, multiview video coding has attracted great attention from industries and research institutes. However, the heavy computational complexity limits its practical applications. In this paper, a fast disparity and motion estimation for multiview video coding is presented, based on the correlations between the neighboring cameras and between the motion and the disparity. In the proposed approach, first, a search region estimation is proposed to reduce the disparity estimation complexity according to that the camera set is usually fixed and therefore the disparity between the two neighboring views can be limited to an estimable range. Second, a motion vector derivation is given based on the geometric relationship between the motion and the disparity. In addition, an early termination scheme is provided to further reduce the number of reference frames. The experimental results show that roughly 50% time saving for disparity and motion computing can be reached when compared to the anchor in multiview video coding test model JSVM only with negligible coding efficiency loss.

Analysis of fast block matching motion estimation algorithms for video super-resolution systems

Abstract: In general, all the video super-resolution (SR) algorithms present the important drawback of a very high computational load, mainly due to the huge amount of operations executed by the motion estimation (ME) stage. Commonly, there is a trade-off between the accuracy of the estimated motion, given as a motion vector (MV), and the computational cost associated. In this sense, the ME algorithms that explore more exhaustively the search area among images use to deliver better MVs, at the cost of a higher computational load and resources use. Due to this reason, the proper choice of a ME algorithm is a key factor not only to reach real-time applications, but also to obtain high quality video sequences independently of their characteristics. Under the hardware point of view, the preferred ME algorithms are based on matching fixed-size blocks in different frames. In this paper, a comparison of nine of the most representative Fast Block Matching Algorithms (FBMAs) is made in order to select the one which presents the best tradeoff between video quality and computational cost, thus allowing reliable real-time hardware implementations of video super-resolution systems.