We propose a novel method of supervised feature projection called class-distance-based discriminant analysis (CDDA), which is suitable for automatic age estimation (AAE) from facial images. Most methods of supervised feature projection, e.g., Fisher discriminant analysis (FDA) and local Fisher discriminant analysis (LFDA), focus on determining whether two samples belong to the same class (i.e., the same age in AAE) or not. Even if an estimated age is not consistent with the correct age in AAE systems, i.e., the AAE system induces error, smaller errors are better. To treat such characteristics in AAE, CDDA determines between-class separability according to the class distance (i.e., difference in ages); two samples with similar ages are imposed to be close and those with spaced ages are imposed to be far apart. Furthermore, we propose an extension of CDDA called local CDDA (LCDDA), which aims at handling multimodality in samples. Experimental results revealed that CDDA and LCDDA could extract more discriminative features than FDA and LFDA.

Motion blur in TFT-LCD is caused by sample and hold characteristic, slow response time of liquid crystal, and the inconsistency between object tracking of the human eye and the actual object location. In order to solve this problem, a high frame rate driving method based on motion estimation and motion compensation has been applied to LCD products. However, as the required processing time of motion estimation increases in LCD TV and monitor systems, real-time video image processing becomes more difficult. Frame interpolation through the large macro block (MB) size has limitations to detect small objects. So, this paper proposes the efficient motion estimator architecture which uses seven kinds of macro blocks to enhance the accuracy of motion estimation and combines the parallel processing with pre-computation technology and hardware optimization for high-speed processing. Also, for increased efficiency in the hardware architecture, we employed an I2C (Inter Integrated Circuit) communication unit to control the key parameters easily through the personnel computer. Simulation results show that the critical path at the motion estimator is reduced by about 27.47% compared to the conventional structure. As a result, the proposed motion estimator will be applicable for the high-speed frame interpolation of variable video.

The purpose of this study was to clarify whether viewers can perceive a digitally deteriorated image while pursuing a speedily moving digitally compressed image. We studied the perception characteristics of false contours among the various digital deteriorations for the four types of displays i.e. CRT, PDP, EL, LCD by changing the gradation levels and the speed of moving image as parameters. It is known that 8 bits is not high enough resolution for still images, and it is assumed that 8 bits is also not enough for an image moving at less than 5 deg/sec since the tracking accuracy of smooth pursuit eye movement (SPEM) is very high for a target moving at less than 5 deg/sec. Given these facts, we focused on images moving at more than 5 deg/sec. In our results, the images deteriorated by a false contour at a gradation level less than 32 were perceived by every subject at almost all velocities, from 5 degrees/sec to 30 degrees/sec, for all four types of displays we used. However, the perception rate drastically decreased when the gradation levels reached 64, with almost no subjects detecting deterioration for gradation levels more than 64 at any velocity. Compared to other displays, LCDs yielded relatively high recognition rates for gradation levels of 64, especially at lower velocities.

A novel data serializer is proposed for use in mobile TFT-LCD driver ICs. The proposed data serializer adopting hierarchical switching and repeater/separator schemes provides 82% power reduction and 27% speed improvement with 27% area saving. Measured overall power consumption of a TFT-LCD driver IC with the proposed data serializer was reduced by as much as 49%.

We proposed a method for reducing LCD motion blur in MPEG domain and analyzing the cause of LCD motion blur. The problem of LCD motion blur is caused by slow response time of liquid crystal and hold-type displaying method of LCDs. The proposed method uses MPEG motion vectors and frequency coefficients of DCT blocks to improve the motion blurs. First, we interpreted the aperture and response time effect of LCD in frequency domain then, modeled sharpening mask filters for the compensation. We confirmed the reduction of motion blurs in LCDs by a motion image simulator.

LCD Automatic Vision Inspection (AVI) systems automatically detect defect features and measure their sizes via camera vision. AVI systems usually report different measurements on the same defect with some variations on position or rotation mainly because we get different images. This is caused by possible variations in the image acquisition process including optical factors, non-uniform illumination, random noise, and so on. For this reason, conventional area based defect measuring method has some problems in terms of robustness and consistency. In this paper, we propose a new defect size measuring method to overcome these problems. We utilize volume information which is completely ignored in the area based conventional defect measuring method. We choose a bell shape as a defect model for experiment. The results show that our proposed method dramatically improves robustness of defect size measurement. Given proper modeling, the proposed volume based measuring method can be applied to various types of defect for better robustness and consistency.

Using frictional force microscopy (FFM), the friction surface characteristics were compared between twisted nematic (TN) mode and vertical alignment (VA) mode alignment films (AFs). The friction asymmetry was detected depending on temperature conditions on TN mode AF, but not on VA mode AF. The difference between two modes was explained by leaning intermolecular repulsion caused by the pre-tilt angle uniformity and the density of side chain. No level difference according to temperature conditions appeared when the pre-tilt angle were measured after liquid crystal (LC) injection.

Slit-Mura defect is a notorious yield flaw of color filters. In this study, an innovative non-contact in-line optical inspection method is developed to detect low contrast slit Mura through quantitative measurements by a spectrometer. Using the features of either thickness or chromaticity profiles across a slit Mura, a thickness difference from 21 nm to 41 nm of color filters can be differentiated accurately. Thus, the quality of color filters can be accessed in-line during the manufacturing process TFT-LCDs.

We developed new principle of electronic paper that is one side (for 2D image) or double side (for stereoscopic 3D image) light printable rewritable matter with polarization dependent gray scale. It consists of one or two liquid crystal displays based on Optical Rewritable (ORW) technology, which is the development of rotation azo-dye photoalignment. Each ORW display uses bare plastic or polarizers as substrates. The conductor is not required, as the image is formed by rewritable states of azimuthal direction, which results in 2D pattern of the liquid crystal twist angle. Continuous grey image maintains proper performance even when the device is bent. Simple construction provides durability and low cost, thin substrates minimize parallax for 3D image. Fluorescent dye dopant of liquid crystal partly absorbs light in blue and re-emit in green specter range improving photopic reflection and enhancing color of the ORW e-paper.

Gamma correction is an essential function and is time consuming task in every display device such as CRT and LCD. And gray scale CCT reproduction in most LCD are quite different from those of standard CRT. An automated fast and accurate display adjusment method and system for gamma correction and for constant gray scale CCT calibration of mobile phone LCD is presented in this paper. We develop the test pattern disply and register control program in mobile phone and devleop automatic measure program in computer using spectroradimeter. The proposed system is maintain given gamma values and CCT values accuratly. In addition, This system is possible to fast mobile phone LCD adjusment within one hour.

We report effects of washing rubbed polyimide film on the near surface. Especially we focused dependence of solvent. Rubbed polyimide films have been used as liquid crystal alignment films in Liquid crystal displays (LCDs), and in actual LCD panel fabrication washing on film surfaces after rubbing is essential process to remove dust and pollution. We investigated the effects of washing by grazing incidence X-ray diffraction (GIXD) measurements. In GIXD, the X-ray penetration into the polymer was changed from 8 nm (suface sensitive) to 4 nm (bulk sensitive) by variation of the X-ray incidence angle. It was found that crystallization near the surface induced by soaking was considerably dependent on solvent. However, in-plane distribution of the surface polymer chains of polyimide film was not found to be dependent on the solvents.

The TFT-LCD image has non-uniform brightness that is the major difficulty of finding the visible defect called Mura in the field. To facilitate Mura detection, background signal shading should level off and Mura signal must be amplified. In this paper, Mura signal amplification and background signal flattening method is proposed based on human visual system (HVS). The proposed DC normalized contrast sensitivity function (CSF) is used for the Mura signal amplification and polynomial regression (PR) is used to level off the background signal. In the enhanced image, tri-modal thresholding segmentation technique is used for finding Dark and White Mura at the same time. To select reliable defect, falsely detected invisible region is eliminated based on Weber's Law. By the experimental results of artificially generated 1-d signal and TFT-LCD image, proposed algorithm has novel enhancement results and can be applied to real automated inspection system.

In this paper, the impact of display on quality assessment is addressed. Subjective quality assessment experiments have been performed on both LCD and CRT displays. Two sets of still images and two sets of moving pictures have been assessed using either an ACR or a SAMVIQ protocol. Altogether, eight experiments have been led. Results are presented and discussed, some differences are pointed out. Concerning moving pictures, these differences seem to be mainly due to LCD moving artefacts such as motion blur. LCD motion blur has been measured objectively and with psycho-physics experiments. A motion-blur metric based on the temporal characteristics of LCD can be defined. A prediction model have been then designed which predict the differences of perceived quality between CRT and LCD. This motion-blur-based model enables the estimation of perceived quality on LCD with respect to the perceived quality on CRT. Technical solutions to LCD motion blur can thus be evaluated on natural contents by this mean.

A cross-coupled charge pump with internal pumping capacitor, which is advantageous from a point of minimizing TFT-LCD driver IC module, is newly proposed in this paper. By using NMOS and PMOS diodes connected to boosting nodes from VIN nodes, the pumping node is precharged to the same value at the pumping node in starting pumping. Since the first-stage charge pump is designed differently from the other stage pumps, a back current of pumped charge from charge pumping node to input stage is prevented. As a pumping clock driver is located in front of pumping capacitor, the driving capacity is improved by reducing a voltage drop of the pumping clock line from parasitic resistor. Finally, a layout area is decreased more compared with the conventional cross-coupled charge pump by using a stack-MIM capacitor. A proposed charge pump for TFT-LCD driver IC is designed with 0.13 µm triple-well DDI process, fabricated, and tested.

Design automation of LCD driver circuits is not sophisticatedly established. Display fineness of an LCD panel depends on a performance metric, ratio of pixel voltage to video voltage (RPV). However, there are several other important metrics, such as area, and the best circuit cannot be decided uniquely. This paper proposes a design automation technique for a LCD column driver to provide several circuit design results with different performance so that designers can select an appropriate design among them. The proposed technique is evaluated with an actual design data, and experimental results show that the proposed method successfully performs technology migration by transistor sizing. Also, the proposed technique is experimentally verified from points of solution quality and computational time.

The thin film transistor liquid crystal display (TFT-LCD) image has nonuniform brightness, which is a major difficulty in finding the Mura defect region. To facilitate Mura segmentation, globally widely varying background signal must be flattened and then Mura signal must be enhanced. In this paper, Mura signal enhancement and background-signal-flattening methods using wavelet coefficient processing are proposed. The wavelet approximation coefficients are used for background-signal flattening, while wavelet detail coefficients are employed to magnify the Mura signal on the basis of an adapted contrast sensitivity function (CSF). Then, for the enhanced image, trimodal thresholding segmentation technique and a false-region elimination method based on the human visual system (HVS) are employed for reliable Mura segmentation. The experimental results show that the proposed algorithms produce promising results and can be applied to automated inspection systems for finding Muras in a TFT-LCD image.

The power reduction of display devices has become an important issue for extending battery life and running time when they are used in digital multimedia broadcasting (DMB) mobile phones. DMB mobile phones generally use 16-bit data per pixel to reduce power consumption even though a liquid crystal display (LCD) graphic controller can support 16-, 18-, and 24-bit data per pixel. Also, the total transmission time of 16-bit data per pixel is only half that for 18- and 24-bit data per pixel. Decoded 24-bit image data in the frame memory of a DMB decoder are asymmetrically truncated to 16-bit image data. This results in a lack of smoothness such as blocking effects and/or pseudo edge artifacts. To solve these problems, the author proposes and implements a new asymmetric pixel data truncation error compensation algorithm using 1-bit least significant bit (LSB) data expansion with correlated color information for the purpose of ensuring smoothness. In the experimental results, the proposed algorithm is able to correct various artifacts.

We propose a filtering method for optimal estimation of TFT-LCD's surface region except defect's region. To estimate the non-uniform intensity variation on TFT-LCD surface region, the 4-directional Gaussian filter based on image pyramid structure is proposed. The experimental result verified the proposed method's performance

In this paper, I propose dynamic gamma control (DGC) as a new contrast enhancement technology for liquid crystal displays. Unlike conventional technologies involving the manipulation of digital image data, DGC modifies analog gamma reference voltages in accordance with the image data distribution. A digital gamma buffer (DGB) and a new system architecture were developed for DGC implementation. Experimental results show that DGC can increase the contrast ratio of 5 images twofold on average.

We analyzed the correlation between three kinds of visualization of the motion blurs (colour of blurs, luminance of the blur and sharpness of object images) and physical properties in regard to image properties and panel characteristics. We also performed subjective evaluations to specify optimal or allowable level of motion blurring with various images on one CRT display and four types of LCDs with various characteristics.