• Title/Summary/Keyword: QCIF

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A Study on the New BC-ABBM Motion Estimation Algorithm for Low Bit Rate Video Coding (저 전송률 비디오 압축을 위한 새로운 BC-ABBM 움직임 추정 알고리즘에 관한 연구)

  • 이완범;김환용
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.7C
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    • pp.946-953
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    • 2004
  • Fast search and conventional boolean matching motion estimation algorithms reduce computational complexity and data processing time but this algorithms have disadvantages that is difficult of implementation of hardware because of high control overhead and that is less performance than Full search Algorithm(FA). This paper present new all binary block matching algorithm, called Bit Converted All Binary Block Matching(BC-ABBM). Proposed algorithm have performance closed to the FA by boolean only block matching that may be very efficiently implemented in hardware for low bit rate video communication. Simulation results show that the PSNR of the proposed algorithm is about 0.04dB loss than FA but is about 0.6 ∼ 1.4dB gain than fast search algorithm and conventional boolean matching algorithm.

A 2' QCIF Flexible OTFT driven AM-OLED Display

  • Suh, Kyung-Soo;You, In-Kyu;Kang, Seung-Youl;Ahn, Seong-Deok;Oh, Ji-Young;Kim, Gi-Hyun;Baek, Kyu-Ha;Kim, Chul-Am;Hwang, Chi-Sun;KoPark, Sang-Hee;Yang, Yong-Suk;Chung, Sung-Mook;Lee, Jeong-Ik;Do, Lee-Mi;Chu, Hye-Yong;Kang, Kwang-Yong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.181-185
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    • 2006
  • The flexible 2-inch AMOLED with $176{\times}144$ pixels has been demonstrated using top emission OLED driven by organic thin film transistors (OTFTs). For the development of AMOLED display on plastic substrate, we have developed several integration and unit process technologies. Through the optimization of the process based on plastic substrate, OTFT backplane with 2 transistors and 1 capacitor in a pixel has been fabricated and integrated with top emission OLED. The active addressing by OTFT driving circuit has been achieved and green light with 15 $cd/m^2$ at 15V has been observed.

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Real-time fractal coding implementation using the PC (PC를 이용한 실시간 프랙탈 부호화 구현)

  • 김재철;박종식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.11
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    • pp.2789-2800
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    • 1996
  • Real time fractal coding for successive QCIF 144*176 luminance images has been implemented on a 50MHz IBM 486 personal computer. To satisfy the frame encoding speed and data compression ratio, following algorithms are adopted. In order to minimize encoding time, extension SAS being not searching of domain blocks is used. for reducing the bits per pixel, conventioal 4*4 range block is extended to 8*8 range block. and range block extension decrease quality of decoded image. For improvement quality of decoded image, the paper apply quad-tree partition mothod. In order to divide **8 range block, self-simiarity is compared 8*8 range block with spatial contractive transformed 8*8 domain block. According to self-simiarity, the block is partitioned and owing to block partition, increased encoding time is minimized. According to self-simiarity of 8*8 range block and spatial contractive transformed 8*8 domain block, number of fractal factor is varied. Simultaneously with minimizing the decrement of decoded image's quality, transmittion rate and encoding time is shorted. The results enable us to process the real-time fractal coding. For the claire test image, the average PSNR was 32.4dB, 0.12 bit rates and 33ms coding time per frame.

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A Protective Layer on the Active Layer of Al-Zn-Sn-O Thin-Film Transistors for Transparent AMOLEDs

  • Cho, Doo-Hee;KoPark, Sang-Hee;Yang, Shin-Hyuk;Byun, Chun-Won;Cho, Kyoung-Ik;Ryu, Min-Ki;Chung, Sung-Mook;Cheong, Woo-Seok;Yoon, Sung-Min;Hwang, Chi-Sun
    • Journal of Information Display
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    • v.10 no.4
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    • pp.137-142
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    • 2009
  • Transparent top-gate Al-Zn-Sn-O (AZTO) thin-film transistors (TFTs) with an $Al_2O_3$ protective layer (PL) on an active layer were studied, and a transparent 2.5-inch QCIF+AMOLED (active-matrix organic light-emitting diode) display panel was fabricated using an AZTO TFT backplane. The AZTO active layers were deposited via RF magnetron sputtering at room temperature, and the PL was deposited via two different atomic-layer deposition (ALD) processes. The mobility and subthreshold slope were superior in the TFTs annealed in vacuum and with oxygen plasma PLs compared to the TFTs annealed in $O_2$ and with water vapor PLs, but the bias stability of the TFTs annealed in $O_2$ and with water vapor PLs was excellent.

Center Average Shrink Method for DTV-to-DMB video transcoding (DTV-to-DMB 비디오 변환을 위한 Center Average 축소 방식)

  • Yoo, Won-Hyuck;Jeong, Won-Sik;Kim, Kyu-Heon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2005.11a
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    • pp.185-188
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    • 2005
  • DTV-to-DMB 비디오 변환을 위해서는 기본적으로 MPEG-2 MP@HL의 HDTV/SDTV급 영상을 MPEG-4 AVC BP@1.3의 QCIF/QVGA/WDF/CIF급 영상으로 변환하는 과정이 필요하다. 본 논문에서는 DTV-to-DMB 비디오 변환을 위해 DTV의 고해상도 영상을 DMB의 저해상도 영상으로 축소하는 방식을 제안하고 있다. DTV-to-DMB 비디오 변환은 실시간 변환이 고려되어야 하며, 실시간 변환을 위해서는 축소 방식의 시간 복잡도가 고려 되어야 한다. 일반적으로 낮은 시간 복잡도를 갖는 영상 축소 방식으로는 대상 영상의 하나의 픽셀을 참조 영상 내 대응하는 픽셀들 중 한 픽셀을 선택하여 결정하는 방식(Just Get A Pixel)이 있으며, 참조 영상의 대응하는 픽셀들의 평균값을 선택하는 방식 (Average Shrink)과 중간값을 선택하는 방식 (Median Shrink)이 있다. 한편, DTV 영상은 인터레이스 방식을사용하며 DMB의 프로그레시브 방식 영상으로 변환 처리 과정에서, 움직임이 큰 영상에 대해 사물의 윤곽선이 계단 모양으로 보이는 재그 에지 (Jagged Edge) 현상이 나타난다. 본 논문에서는 대상 영상의 한 픽셀을 참조 영상의 대응하는 픽셀들 중 중간 위치의 몇 개 픽셀들과 주변 인접 픽셀들을 선출하여 그것들의 평균값 (Average)을 구하여 결정하는 Center Average 축소 방식을 제안한다. 제안된 방식은 기본적인 축소 방식을 기반으로 하여 낮은 시간 복잡도를 갖으며, 재그 에지 (Jagged Edge) 현상을 줄여 준다.

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Development of flexible 3.5' QCIF (176 X144 pixels) OTFT driven OLED;Integration technologies compatible with normal semiconductor processes

  • Kang, Seung-Youl;Ahn, Seong Deok;Oh, Ji-Young;Kim, Gi-Hyun;Koo, Jae Bon;You, In-Kyu;Kim, Chul-Am;Hwang, Chi-Sun;KoPark, Sang-Hee;Yang, Yong-Suk;Chung, Sung-Mook;Lee, Jeong-Ik;Chu, Hye-Yong;Suh, Kyung-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.62-65
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    • 2007
  • Conventional semiconductor processes have been utilized to fabricate 3.5-inch OTFT-driven OLEDs with a resolution of $176\;{\times}\;144$ pixels on plastic substrates. By using a PC-OVD method to deposit a pentacene layer and optimizing patterning and the following processes, we could complete a uniform and reliable integration procedure for an active matrix organic light emitting devices on a plastic substrate. The technical importance of ours is the applicability of conventional semiconductor process to organic materials on plastic substrates. Although there are many hurdles to overcome, our approach and technical improvements are proved to be applicable to plastic electronics.

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Conservative Approximation-Based Full-Search Block Matching Algorithm Architecture for QCIF Digital Video Employing Systolic Array Architecture

  • Ganapathi, Hegde;Amritha, Krishna R.S.;Pukhraj, Vaya
    • ETRI Journal
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    • v.37 no.4
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    • pp.772-779
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    • 2015
  • This paper presents a power-efficient hardware realization for a motion estimation technique that is based on the full-search block matching algorithm (FSBMA). The considered input is the quarter common intermediate format of digital video. The mean of absolute difference (MAD) is the distortion criteria employed for the block matching process. The conventional architecture considered for the hardware realization of FSBMA is that of the shift register-based 2-D systolic array. For this architecture, a conservative approximation technique is adapted to eliminate unnecessary MAD computations involved in the block matching process. Upon introducing the technique to the conventional architecture, the power and complexity of its implantation is reduced, while the accuracy of the motion vector extracted from the block matching process is preserved. The proposed architecture is verified for its functional specifications. A performance evaluation of the proposed architecture is carried out using parameters such as power, area, operating frequency, and efficiency.

A Study on the Method of Minimizing the Bit-Rate Overhead of H.264 Video when Encrypting the Region of Interest (관심영역 암호화 시 발생하는 H.264 영상의 비트레이트 오버헤드 최소화 방법 연구)

  • Son, Dongyeol;Kim, Jimin;Ji, Cheongmin;Kim, Kangseok;Kim, Kihyung;Hong, Manpyo
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.2
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    • pp.311-326
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    • 2018
  • This paper has experimented using News sample video with QCIF ($176{\times}144$) resolution in JM v10.2 code of H.264/AVC-MPEG. The region of interest (ROI) to be encrypted occurred the drift by unnecessarily referring to each frame continuously in accordance with the characteristics of the motion prediction and compensation of the H.264 standard. In order to mitigate the drift, the latest related research method of re-inserting encrypted I-picture into a certain period leads to an increase in the amount of additional computation that becomes the factor increasing the bit-rate overhead of the entire video. Therefore, the reference search range of the block and the frame in the ROI to be encrypted is restricted in the motion prediction and compensation for each frame, and the reference search range in the non-ROI not to be encrypted is not restricted to maintain the normal encoding efficiency. In this way, after encoding the video with restricted reference search range, this article proposes a method of RC4 bit-stream encryption for the ROI such as the face to be able to identify in order to protect personal information in the video. Also, it is compared and analyzed the experimental results after implementing the unencrypted original video, the latest related research method, and the proposed method in the condition of the same environment. In contrast to the latest related research method, the bit-rate overhead of the proposed method is 2.35% higher than that of the original video and 14.93% lower than that of the latest related method, while mitigating temporal drift through the proposed method. These improved results have verified by experiments of this study.

Uni-directional 8X8 Intra Prediction for H.264 Coding Efficiency (H.264에서 성능향상을 위한 Uni-directional 8X8 인트라 예측)

  • Kook, Seung-Ryong;Park, Gwang-Hoon;Lee, Yoon-Jin;Sim, Dong-Gyu;Jung, Kwang-Soo;Choi, Hae-Chul;Choi, Jin-Soo;Lim, Sung-Chang
    • Journal of Broadcast Engineering
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    • v.14 no.5
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    • pp.589-600
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    • 2009
  • This paper is ready to change a trend of a ultra high definition (UHD) video image, and it will contribute to improve the performance of the latest H.264 through the Uni-directional $8{\times}8$ intra-prediction idea which is based on developing a intra prediction compression. The Uni-directional $8{\times}8$ intra prediction is focused on a $8{\times}8$ block intra prediction using $4{\times}4$ block based prediction which is using the same direction of intra prediction. This paper describes that the uni-directional $8{\times}8$ intra-prediction gets a improvement around 7.3% BDBR only in the $8{\times}8$ block size, and it gets a improvement around 1.3% BDBR in the H.264 applied to the multi block size structures. In the case of a larger image size, it can be changed to a good algorithm. Because the video codec which is optimized for UHD resolution can be used a different block size which is bigger than before(currently a minimum of $4{\times}4$ blocks of units).