Mon-Chau Shie

Dynamic contrast enhancement based on histogram specification

A novel contrast enhancement algorithm is proposed. The proposed approach enhances the contrast without losing the original histogram characteristics, which is based on the histogram specification technique. It is expected to eliminate the annoying side effects effectively by using the differential information from the input histogram. The experimental results show that the proposed dynamic histogram specification (DHS) algorithm not only keeps the original histogram shape features but also enhances the contrast effectively. Moreover, the DHS algorithm can be applied by simple hardware and processed in real-time system due to its simplicity.

A Fully Digital Time-Domain Smart Temperature Sensor Realized With 140 FPGA Logic Elements

To explore the possibility of soft intellectual property implementation, a fully digital smart temperature sensor without any full-custom device is proposed for painless VLSI or system-on-chip integrations. The signal is processed thoroughly in time domain instead of conventional voltage or current domain. A cyclic delay line is used to generate the pulse with a temperature-proportional width. The timing reference is just the input clock and a counter instead of voltage or current analog-to-digital converter is utilized for digital output coding. The circuit was implemented by field-programmable gate array chips for functionality verification and performance evaluation. Realized with as few as 140 logic elements, the proposed smart sensor was measured to have an error of -1.5 ~ 0.8 degC over the full commercial IC temperature operation range of 0 degC-75 degC for thermal self-sensing or monitoring. The effective resolution can be made better than 0.1 degC easily, and the power consumption is 8.42 muW at a sampling rate of 2 samples/s. The longest conversion time is around 260 s, and a conversion rate of 3 kHz at least is promised.

A Simple and Accurate Color Face Detection Algorithm in Complex Background

Human face detection plays an important role in many applications such as video surveillance, face recognition, and face image database management. This paper describes a fast face detection algorithm with accurate results. We use lighting compensation to improve the performance of color-based scheme, and reduce the computation complexity of feature-based scheme. Our method is effective on facial variations such as dark/bright vision, close eyes, open mouth, a half-profile face, and pseudo faces. It is worth stressing that our algorithm can also discriminate cartoon and human face correctly. The experimental results show that our approach can detect a frame in 111 msecs with the 92.3% detection rate

Fast and efficient median filter for removing 1-99% levels of salt-and-pepper noise in images

This paper proposes a new median filter using prior information to capture natural pixels for restoration. In addition to being very efficient in logic execution, the proposed filter restores corrupted images with 1-99% levels of salt-and-pepper impulse noise to satisfactory ones. Without any iteration for noise detection, it intuitively and simply recognizes impulse noises, while keeping the others intact as nonnoises. Depending on different noise ratios at an image, two different sets of masked pixels are employed separately for the adoption of candidates for median finding. Furthermore, no limit to the size of mask windows assures that a proper median can be found. The simple logic of the proposed algorithm achieves significant milestones on the fidelity of a restored image. Moreover, the very fast execution speed of the proposed filter is very suitable for being applied to real-time processing. Relevant experimental results on subjective visualization and objective digital measure are reported to validate the robustness of the proposed filter.

Intelligent energy monitoring system based on ZigBee-equipped smart sockets

The intelligent home appliance monitoring is the mainstream development of the future automation and networking technology. Appliance operation can be easily monitored through sensing and other similar perceptions of the corresponding power link. These products of smart energy monitoring system communicate with one another via intelligent sockets equipped with ZigBee wireless transceivers. A home-based remote server enables remote monitoring and control of electrical home appliances. The use of mobile internet in portable devices, especially in smartphones and tablet PCs, provides great advantage and flexibility for remote control. The status and power consumption information of all monitored appliances are stored in the remote server. The corresponding analysis of such power consumption data can be provided to the power company for smart grid planning and the user for energy saving through rescheduling and safe power usage via abnormal situation warning.

Polygonal routing network for FPGA/FPIC

The programmable routing network of Field Programmable Gate Array (FPGA) and Field Programmable Interconnection Chip (FPGA) affects its performance, die size, and routability. This paper proposes a polygonal routing network that consists of polygonal switch modules and many rectangular connection modules. For a logic module with 2n pins, the number of switches used in the polygonal routing module is less than the conventional routing module by O(/spl radic/n).

Adaptive fast block mode decision algorithm for H.264/AVC

H.264/AVC outperforms the previous coding standards thanks to variable block size motion compensation (VBSMC) ranging from 4×4 to 16×16 in interframe coding. However, this new feature causes extremely high computation complexity when rate-distortion optimization(RDO) is performed using full mode decision. In this paper, we propose an adaptive fast block mode decision algorithm (AFBMD) leveraging the following characteristics to significantly reduce the complexity. (1) detecting stationarity of a block by using sum of absolute difference (SAD) and the biggest pixel difference. (2) exploiting the left and upper block modes to determine the block mode priority order. (3) comparing the RDcosts of the current best block mode and the block modes in the priority order that attempt to early terminate the block mode decision. Compared with the full mode decision (FMD) [20], the experimental results shown that the proposed algorithm reduces the mode decision complexity up to 77% while still maintains almost the same image quality as FMD.

A Fully Digital Low Cost Time Domain Smart Temperature Sensor with Extremely Tiny Size

To explore the possibility of soft IP implementation, a fully digital smart temperature sensor without any full-custom device is proposed for painless VLSI or SOC on-chip integrations. The signal is processed thoroughly in time domain instead of conventional voltage or current domain. A cyclic delay line is used to generate the thermally sensitive pulse with a width proportional to the measured temperature. The timing reference is just the input clock, and a counter instead of voltage or current analog-to-digital converter is utilized for digital output coding. The circuit is realized by FPGA chips for functionality verification and performance evaluation. Implemented with as few as 140 Logic Elements, the proposed smart sensor was measured to have an error of -0.7degC~0.9degC over a wide temperature range of -40degC~130degC. The effective resolution is better than 0.1degC, and the power consumption is 8.42 muW at a sample rate of 2 samples/s. The performance is as good as those of most full-custom predecessors. The longest conversion time is around 260 mus, and a conversion rate of 3 kHz at least is promised.

Center of mass-based adaptive fast block motion estimation

This work presents an efficient adaptive algorithm based on center of mass (CEM) for fast block motion estimation. Binary transform, subsampling, and horizontal/vertical projection techniques are also proposed. As the conventional CEM calculation is computationally intensive, binary transform and subsampling approaches are proposed to simplify CEM calculation; the binary transform center of mass (BITCEM) is then derived. The BITCEM motion types are classified by percentage of (0,0) BITCEM motion vectors. Adaptive search patterns are allocated according to the BITCEM moving direction and the BITCEM motion type. Moreover, the BITCEM motion vector is utilized as the initial search point for near-still or slow BITCEM motion types. To support the variable block sizes, the horizontal/vertical projections of a binary transformed macroblock are utilized to determine whether the block requires segmentation. Experimental results indicate that the proposed algorithm is better than the five conventional algorithms, that is, three-step search (TSS), new three-step search (N3SS), four three-step search (4SS), block-based gradient decent search (BBGDS), and diamond search (DS), in terms of speed or picture quality for eight benchmark sequences.

Markov model fuzzy-reasoning based algorithm for fast block motion estimation

Abstract This paper presents a Markov model fuzzy-reasoning based algorithm for fast block motion estimation. To reduce computational complexity, the existing fast search algorithms move iteratively toward the winning point based only on a finite set of search points in every stage. Despite the efficiency of these algorithms, the search process is easily trapped into local minima, especially for high activity video sequences. To overcome this difficulty, we propose a three-states Markov model based algorithm that invokes the fuzzy-reasoning to provide the search an acceptance probability of being able to move out of local minima. Two schemes are employed to further enhance the performance of the algorithm. First, a set of initial search points that exploit high correlations among the motion vectors of the temporally and spatially adjacent blocks as well as their surrounding points are used. Second, an alternate search strategy is addressed to cover more area without increasing computations. Simulation results show that the new algorithm offers superior performance with lower computational complexity and picture quality increase in terms of search points/block and MSE/pel, respectively, compared with the previous works in various scenarios.