• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1471-1481
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• 1998

In this paper, we propose a new digital image stabilization scheme based on the bit-plane matching. In the proposed algorithm, the conventional motion estimation algorithms are applied to the binary images extracted from the bit-plane images. It is shown that the computational complexity of the proposed algorithm can be significantly reduced by replacing the arithmetic calculations with the binary Boolean functions, while the accuracy of motion estimation is maintained. Furthermore, an adaptive algorithm for selecting a bit-plane in consideration of changes in external illumination can provide the robustness of the proposed algorithm. We compared the proposed algorithm with existing algorithms using root mean square error (RMSE) on the basis of the brute-force method, and proved experimentally that the proposed method detects the camera motion more accurately than existing algorithms. In addition, the proposed algorithm performs digital image stabilization with less computation.

• Journal of Broadcast Engineering
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• v.6 no.1
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• pp.41-49
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• 2001

Digital watermarking has been proposed for copyright protection of digital data. According to the property of an embedded watermark, it is classified into two categories, robust watermarking and fragile watermarking. The former is used for copyright protection, and the latter applies to the authentication/integrity to verify the authenticity of data, If an Image has been modified or forged. the embedded watermark cannot be extracted from the Image. As a results, it is possible to defect the modification of the image. As pixels are represented by tilts, the modification of bits corresponds to the alteration of the image. In this paper, a new fragile watermarking is proposed In which two watermarks are embedded in order to detect some modification occurred In high and low bit Planes. From simulation results, the embedded watermark is Invisible in a watermarked image and we can locale some Places where the modification occurring

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.33-40
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• 2014

In this paper we propose new image coding using wavelet transform. The new method constructs hierarchical bit plane and progressively transports each bit plane. The Proposed algorithm not only supports multi-resolution, dividing original image into special band and various resolution using Antonini's wavelet basis function but also reduces blocking effects that come into JPEG. In encoding time this algorithm considers each band characters and priority of transport order, and applies to fast search of image.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.144-154
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• 2011

In this paper, we propose a parallel LDPCA encoding method for fast transform-domain Wyner-Ziv video encoding which is suitable in an ultra fast and low power video encoding. The conventional transform-domain Wyner-Ziv video encoding performs LDPCA channel coding of quantized transform coefficients in bitplane-serial fashion, which takes about 60% of total encoding time, and this computational complexity becomes severer as the bitrate increases. The proposed method binds several bitplanes into one packed message and carries out the LDPCA encoding in parallel. The proposed LDPCA encoding method improves the encoding speed by 8 ~ 55 times. In the experiment, the proposed Wyner-Ziv encoder can encode 700 ~ 2,300 QCIF size frames per second with GOP=64. The method can be applied to the pixel-domain Wyner-Ziv encoder using LDPCA, and has a wide scope of application.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.155-158
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• 2004

본 논문은 비트 플레인의 위치에 따라 블록별 적응적인 임계값를 이용하여 정보를 삽입하는 스테가노그라피 방법을 연구하였다. 다양한 이미지를 대상으로 고정 임계값을 적용하는 기존의 방법과 영상의 특징에 따라 비트 플레인별 임계값이 적응적으로 산출되는 제안한 방법에 대해서 최대용량을 측정하고, 같은 양의 정보를 삽입한 후 화질을 비교 분석하였다. 그 결과 기존의 방법 보다 용량면이나 화질면에서 나은 결과를 얻을 수 있었다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.136-137
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• 2010

본 논문에서는 고속, 저전력 비디오 부호화에 적합한 변환영역 Wyner-Ziv 분산비디오부호화기를 더욱 고속화하기 위한 병렬처리 방법을 제안한다. 기존에는 변환영역 Wyner-Ziv 분산비디오부호화를 위해 양자화 정보를 비트플레인단위로 분해후 이를 순차적으로 LDPCA 부호화하여 전체 부호화기 연산량에서 LDPCA의 복잡도가 약 54% 정도 차지하였고, 이는 고비트율로 부호화 할수록 더욱 증가하였다. 제안방법은 이를 개선하기 위해 여러 개의 비트플레인을 하나의 심벌 (symbol)로 묶어서 LDPCA 부호화를 수행하여 한 번의 연산으로 여러 개의 데이터를 동시에 처리할 수 있게 한다. 일종의 단일 명령 복수 데이터 처리 (SIMD, Single instruction, multiple data)에 의한 고속화 방법이다. 이를 통해 제안방법은 기존의 순차적 처리 방법에 비해 저비트율에서는 8배, 고비트율에서는 55배까지 LDPCA의 부호화 속도를 향상시켰다. 결과적으로 전체 부호화에서 LDPCA의 상대적인 복잡도 비율은 4%정도로 낮아지게 되었으며 Wyner-Ziv 영상의 부호화 속도도 약 1.5 ~ 2배까지 향상되었다. 제안방법은 LDPCA를 사용하는 다른 Wyner-Ziv 분산비디오부호화 구조에도 적용 가능할 것으로 기대한다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.5
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• pp.509-517
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• 2001

Full-search algorithm requires large amount of computation which causes time delay or very complex hardware architecture for real time implementation. In this paper, we propose a fast motion estimator based on bit-plane matching, which reduce the computational complexity and the hardware cost. In the proposed motion estimator, the conventional motion estimation algorithms are applied to the binary images directly extracted from the video sequence. Furthermore, in the proposed VLSI motion estimator, we employ a Pair of processing cores that calculate the motion vector continuously By controlling the data flow in a systolic fashion using the internal shift registers in the processing cores, we avoid using SRAM (local memory) so that we remove the time overhead for accessing the local memory and adopt lower-cost fabrication technology. We modeled and tested the proposed motion estimator in VHDL, and then synthesized the whole system which has been integrated in a 0.6-$\mu$m triple-metal CMOS chip of size 8.15 X 10.84$\textrm{mm}^2$.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.1245-1248
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• 2022

본 논문에서는 사용자가 보다 간편하게 볼류메트릭 비디오를 소비할 수 있도록 볼류메트릭 비디오 기본 플레이어를 구현하고, 구현한 플레이어에 대하여 성능평가를 진행한다. 본 논문에서 구현한 볼류메트릭 비디오 플레이어는 Draco 와 V-PCC 를 복호화기로 지원하며, 압축 전의 포인트 클라우드 데이터와 Draco 와 V-PCC 로 압축한 비트스트림에 대하여 성능 평가를 진행하였다. 플레이어의 성능을 평가한 결과를 통해 초기 충분한 량의 프레임을 버퍼에 확보할 만큼의 초기 지연시간을 설정하지 않는 이상, 볼류메트릭 비디오를 30fps 이상으로 소비하기에는 어려움이 있음을 확인하였다. 이를 토대로 현재 볼류메트릭 비디오 재생을 위한 기술적 한계를 살펴보고, 볼류메트릭 비디오 플레이어의 성능 향상을 위한 향후 연구개발 방향에 대하여 논의한다.

• Journal of the Korea Society of Computer and Information
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• v.3 no.3
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• pp.89-98
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• 1998

In this paper, we propose new image coding using wavelet transform. The new method constructs hierarchical bit plane and progressively transports each bit plane. The proposed algorithm not only supports multi-resolution, dividing original image into special band and various resolution but also reduces blocking effects that come into JPEG In encoding time, this algorithm considers each band characters and priority of transport order, and applies to fast search of image.

• The Transactions of the Korea Information Processing Society
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• v.4 no.10
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• pp.2640-2650
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• 1997

In this paper we propose new image coding using wavelet transform. The new method constructs hierarchical bit plane and progressively transports each bit plane. The proposed algorithms not only supports multi-resolution, dividing original image into special band and various resolution but also reduces blocking effects that come int JPEG. In encoding time this algorithm considers each band characters and priority of transport order, and applies to fast search of image.