• Journal of the Korean Society for Precision Engineering
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• v.26 no.8
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• pp.7-13
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• 2009

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.569-574
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• 1999

New methods for both color palette design and dithering based on human visual system (HVS) characteristics are proposed. Color quantization for palette design uses the relative visual sensitivity and spatial masking effect of HVS. The dithering operation for printing uses nonlinear quantization, which considers the overlapping phenomena among neighbor printing dots, and then a modified dot-diffusion algorithm is followed to compensate the degradation produced in the quantization process. The proposed techniques can produce high quality image in the low-bit color devices.

• Journal of the Optical Society of Korea
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• v.15 no.4
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• pp.362-367
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• 2011

Organic ($Alq_3$) film, which was coated on a donor plate, was transferred to an organic light emitting diode (OLED) substrate with help of heat generated by a dithering laser beam. The laser beam was diffracted in an acousto-optic modulator (AOM), then focused on the laser-to-heat converting layer of the donor plate; the focused spot followed trajectories guided by rotation of a Galvano-mirror. Three different functional waveforms, sine wave, square wave, and saw tooth wave were applied to the AOM as modulation signal to generate the dithering beam. The fluorescence microscope images of the donor plate showed that the patterns of removed $Alq_3$ film were affected considerably by the modulation waveforms and the phase difference between adjacent dithering beams. Further, the printed images of Alq3 film on the OLED substrate were different from the patterns of removed Alq3 film. Atomic force microscope images indicated that not only direct transfer but also deposition by sublimated vapor of Alq3 contributed to the pattern formation. Printed patterns affected considerably the electricity-to-light conversion characteristics of OLEDs. For uniform transfer, not only the phase relation of dithering beam lines but also adequate waveform were important.

• Journal of IKEEE
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• v.15 no.1
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• pp.29-36
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• 2011

Dithering scheme has been widely used to improve the resolution of DCO(Digitally Controlled Oscillator) in conventional ADPLLs(All Digital Phase Locked Loop). In this paper a new resolution improvement scheme is proposed where a simple DAC is employed to overcome the problems of dithering scheme. A 2.4GHz LC-based DCO has been designed in a $0.13{\mu}m$ CMOS process with an enhanced frequency resolution for wireless local area network applications. It has a frequency tuning range of 900MHz and a resolution of 58.8Hz. The frequencies are controled by varactors in coarse, fine, and DAC bank. The DAC bank consists of an inversion mode NMOS varactor. The other varactor banks consist of PMOS varactors. Each varactor bank is controlled by 8bit digital signal. The designed DCO exhibits a phase noise of -123.8dBc/Hz at 1MHz frequency offset. The DCO core consumes 4.2mA from 1.2V supply.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.88-95
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• 1996

Recently, the use of color data is growing fast in the area of image processing. To represent full resolution image on a limited output device, image has to be quantized an dithered. So, many dithering techniques are foundd in the printing. In this paper, we propose nonlinear quantization to consider the overlapping phenomena of neighboring printing dots and modified dot diffusion algorithm to compensate the color degradation produced in the quantization process. In the modified dot-diffusion quantization errors to be diffused are adjusted to improve both image blur and color change produced in the dot diffusion. The printed image obtained by the proposed color dithering method has higher visual quality an less color degradation than the images by conventional printing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1543-1551
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• 2011

Dithering scheme has been widely used to improve the resolution of DCO(Digitally Controlled Oscillator) in conventional ADPLLs(All Digital Phase Locked Loop). In this paper a new resolution improvement scheme is proposed where a simple DAC(Digital-to-Analog Converter) is employed to overcome the problems of dithering scheme. The frequencies are controled by varactors in coarse, fine, and DAC bank. The DAC bank consists of an inversion mode NMOS varactor. The other varactor banks consist of PMOS varactors. Each varactor bank is controlled by 8bit digital signal. The proposed DCO has been designed in a $0.13{\mu}m$ CMOS process. Measurement results shows that the designed DCO oscillates in 2.8GHz~3.5GHz and has a frequency tuning range of 660MHz and a resolution of 73Hz at 2.8GHz band. The designed DCO exhibits a phase noise of -119dBc/Hz at lMHz frequency offset. The DCO core consumes 4.2mA from l.2V supply. The chip area is $1.3mm{\times}1.3mm$ including pads.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.45-50
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• 2022

This paper compares the equalization performance of the DSE-MMA (Dithered Signed Error-MMA) and DQE-MMA (Dithered Quantized Error-MMA) adaptive equalization algorithm based on the dither signal in order to reduce the intersymbol interference occurs at communication channel. These algorithm was emerged in ordr to reduction of arithmetic operation than current MMA, it makes the independent and identical distribute the quantized error component by performing the 1 or N bit quautizer after adding the dither singal in obtaining the error signal for adapting process. It is possible to improve the robustness performance of adaptive algorithm, but degrade the MSE performance in steady state by dither signal. The paper directly compare the DSE-MMA and DQE-MMA adaptive equalization performance of the same concept of dithering in the same communication channel and signal to noise ratio by computer simulation. As a result of simulation, the DQE-MMA has more better in the every performance index, equalizer output constellation, residual isi, MSE and SER performance, but not in convergence speed.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1781-1784
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• 2007

The increase of repetition rate, the dithering of laser optics, and the extension of pulse duration time are major approaches in improving the picture quality of AMOLEDs fabricated by excimer laser crystallization (ELC). Advanced solid phase crystallization (ASPC) has been developed to improve the uniformity and the process cost. Even though the mobility of ASPC-TFT is lower than that of ELC-TFT, it is high enough to drive AMOLED pixels.

• Journal of Advanced Navigation Technology
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• v.13 no.6
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• pp.984-990
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• 2009

Halftoning is very important image processing techniques in the digital printing industry which is a process of converting a continuous-tone image to bi-level tone image. In this paper we introduce a new digital halftoning method based on maze generation algorithm as a replacement algorithm of halftoning with space-filling curve. Previous error-diffusion methods based on space-filling curve suffer from regular pattern artifacts from uniform scan pattern. We use maze generation algorithm to remove this undesirable pattern of space-filling curve method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5624-5638
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• 2016

A novel method based on Surf points is proposed to detect and lock-track single ground target in aerial videos. Videos captured by moving cameras contain complex motions, which bring difficulty in moving object detection. Our approach contains three parts: moving target template detection, search area estimation and target tracking. Global motion estimation and compensation are first made by grids-sampling Surf points selecting and matching. And then, the single ground target is detected by joint spatial-temporal information processing. The temporal process is made by calculating difference between compensated reference and current image and the spatial process is implementing morphological operations and adaptive binarization. The second part improves KALMAN filter with surf points scale information to predict target position and search area adaptively. Lastly, the local Surf points of target template are matched in this search region to realize target tracking. The long-term tracking is updated following target scaling, occlusion and large deformation. Experimental results show that the algorithm can correctly detect small moving target in dynamic scenes with complex motions. It is robust to vehicle dithering and target scale changing, rotation, especially partial occlusion or temporal complete occlusion. Comparing with traditional algorithms, our method enables real time operation, processing $520{\times}390$ frames at around 15fps.