• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권4호
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• pp.1188-1202
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• 2012

In this paper, we propose a new multi-scale connected coherence tree algorithm (MCCTA) by improving the connected coherence tree algorithm (CCTA). In contrast to many multi-scale image processing algorithms, MCCTA works on multiple scales space of an image and can adaptively change the parameters to capture the coarse and fine level details. Furthermore, we design a Multi-scale Connected Coherence Tree algorithm plus Spectral graph partitioning (MCCTSGP) by combining MCCTA and Spectral graph partitioning in to a new framework. Specifically, the graph nodes are the regions produced by CCTA and the image pixels, and the weights are the affinities between nodes. Then we run a spectral graph partitioning algorithm to partition on the graph which can consider the information both from pixels and regions to improve the quality of segments for providing image segmentation. The experimental results on Berkeley image database demonstrate the accuracy of our algorithm as compared to existing popular methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.980-982
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• 1995

Image coding based on a fractal theory of iterated transformations presents highly compressed image. In this paper, we compress image using the partitioning method which devides image adaptively in horizon and vertical axis. This method can encode image more compactly than the quadtree partitioning method. The maximum range size can be selected as $32{\times}32$ blocks and the minimum size can be $4{\times}4$ blocks. And the domain size is twice as many as the range size.

• 천문학회지
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• 제52권2호
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• pp.49-55
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• 2019

The New Vacuum Solar Telescope (NVST) is the largest solar telescope in China. When using CCDs for imaging, equal-thickness fringes caused by thin-film interference can occur. Such fringes reduce the quality of NVST data but cannot be removed using standard flat fielding. In this paper, a correction method based on multi-scale decomposition and adaptive partitioning is proposed. The original image is decomposed into several sub-scales by multi-scale decomposition. The region containing fringes is found and divided by an adaptive partitioning method. The interference fringes are then filtered by a frequency-domain Gaussian filter on every partitioned image. Our analysis shows that this method can effectively remove the interference fringes from a solar image while preserving useful information.

• 융합신호처리학회논문지
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• 제4권4호
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• pp.7-14
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• 2003

EZW(Embedded Zerotree Wavelet) 알고리즘이 소개된 이래 일련의 내장형 웨이브렛 코딩 방법들이 제안되어져왔다. 이들의 하나의 공통된 특징은 EZW 알고리즘의 기본 아이디어를 근간으로 한다는 점이다. 특히 SPIHT(Set Partitioning in Hierarchy Trees) 알고리즘은 이들 중의 하나로서 산술 코더를 사용하지 않더라도 EZW와 같거나 혹은 더 나은 성능을 제공할 수 있기 때문에 널리 알려져 왔다. 본 연구에서는 내장형 영상코딩을 위한 재귀적 SPIHT(RSPIHT) 알고리즘을 제안하고 그 유효성을 실험적으로 가한다. 제안한 RSPIHT 알고리즘은 매우 단순하고 정형화된 형태를 지니면서 최악의 경우 시간복잡도 O(n)을 가진다. 실험영상들에 대해 T-layer 4 이상에서 SPIHT보다 평균 약 16.4%의 개선된 속도를 얻을 수 있었다. 압축률의 관점에서도 RSPIHT 알고리즘은 실험영상의 T-layer 7 이하에서는 SPIHT와 유사한 결과를 가지나 그보다 큰 T-layer에서는 개선된 결과를 보였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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• pp.179-182
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• 2001

This paper has been studied a wavelet based still image transmission over the wireless channel. EZW(Embedded Zerotree Wavelet) is an efficient and scalable wavelet based image coding technique, which provides progressive transfer of signal resulted in multi-resolution representation. It reduces therefore the reduce cost of storage media. Although EZW has many advantages, it is very sensitive on error. Because coding are performed in subband by subband, and it uses arithmetic coding which is a kind of variable length coding. Therefore only 1∼2bit error may degrade quality of the entire image. So study of error localization and recovery are required. This paper investigates the use of reversible variable length codes(RVLC) and data partitioning. RVLC are known to have a superior error recovery property due to their two-way decoding capability and data partitioning is essential to applying RVLC. In this work, we show that appropriate data partitioning length for each SNR(Signal-to-Noise Power Ratio) and error localization in wireless channel.

• IEIE Transactions on Smart Processing and Computing
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• 제5권4호
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• pp.294-301
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• 2016

In this paper, we present methods to efficiently parallelize iterative 3D image reconstruction by exploiting trigeneous devices (three different types of device) at the same time: a CPU, an integrated GPU, and a discrete GPU. We first present a technique that exploits single instruction multiple data (SIMD) architectures in GPUs. Then, we propose a performance estimation model, based on which we can easily find the optimal data partitioning on trigeneous devices. We found that the performance significantly varies by up to 6.23 times, depending on how SIMD units in GPUs are accessed. Then, by using trigeneous devices and the proposed estimation models, we achieve optimal partitioning and throughput, which corresponds to a 9.4% further improvement, compared to discrete GPU-only execution.

• International Journal of Computer Science & Network Security
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• 제23권7호
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• pp.61-70
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• 2023

Image segmentation is a very crucial step in effective digital image processing. In the past decade, several research contributions were given related to this field. However, a general segmentation algorithm suitable for various applications is still challenging. Among several image segmentation approaches, graph-based approach has gained popularity due to its basic ability which reflects global image properties. This paper proposes a methodology to partition the image with its pixel, region and texture along with its intensity. To make segmentation faster in large images, it is processed in parallel among several CPUs. A way to achieve this is to split images into tiles that are independently processed. However, regions overlapping the tile border are split or lost when the minimum size requirements of the segmentation algorithm are not met. Here the contributions are made to segment the image on the basis of its pixel using min-cut/max-flow algorithm along with edge-based segmentation of the image. To segment on the basis of the region using a homogenous optimum cut algorithm with boundary segmentation. On the basis of texture, the object type using spectral partitioning technique is identified which also minimizes the graph cut value.

• 한국정보통신학회논문지
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• 제9권5호
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• pp.1025-1030
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• 2005

멀티 미디어 사용의 증가에 따라 정보화 사회에 있어 정지 영상 정보를 높은 압축율로 방대한 데이터를 얼마나 빠르게 에러없이 전송 또는 처리 하는가 하는 문제가 요구 되어지고 있다. 본 논문은 정지영상 인코딩 분야에서 다양한 기능과 압축 성능을 보이고 있는 JPEG2000 압축효율 향상을 위하여 저주파 대역에 대한 부호화를 제거하고, 중복비트 제거를 이용한 개선된 분할정렬 알고리즘을 이용하여 웨이블렛 계수를 줄이는 방법을 제안하였다. 실험결과, 제안한 방법을 통해 기존의 JPEG2000 표준보다 더 우수한 양질의 성능과 저 비트율을 확인할 수 있었다.

• 한국정보처리학회논문지
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• 제7권2호
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• pp.365-372
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• 2000

프랙탈 영상 압축(Fractral Image Compression:FIC)의 진화 계산(Evolution Computation)을 이용한 영상 분할(Image Partition)을 소개한다. 프랙탈 영상 압축에서 지역(Ranges)의 영상 분할은 꼭 필요하다[1]. 프랙탈 영상 압축은 쉽고 빠르게 복원된다는 장점을 갖는 데 비해 반복적인 프랙탈 변환의 적용으로 많은 계산량을 필요로 한다는 단점을 가지고 있다. 위와 같은 문제점을 해결하기 위한 방법으로 영상 분할을 하는데 있어 진화 계산을 적용하는 것에 대해 제안한다. 치역 영상(Ranges Image)은 작은 사각(Square) 영상 블록들의 결합된 집합으로 구성할 수 있다. 모집단을 구성하는 하나의 $N_p$는 분할되어진 하나의 코드들이다. 진화 계산에서 각각의 구성은 두 개의 이웃하는 치역은 제외하고 그들의 부모(Parent)로부터 분할을 상속받은 자식 $\sigma$를 생성한다. 자손들의 최적의 영상은 콜라주 정리(Collage Theorem)에 기초를 둔 다음 세대 모집단을 위해 선택되어지고 처리된다. 최적의 영상은 영상 데이터에 포함된 중복성을 포함함으로서 적은 저장 공간을 차지하고 속도 문제에 있어서 효율적이고 영상의 화질에 있어서 다른 부호화를 사용한 기법보다 우수한 성능을 갖는다. 멀티미디어 영상 처리(Multimedia Image Processing)의 진화 계산을 이용한 프렉탈 영상 압축은 영상의 복원과 영상의 질, 고 압축률을 요하는 동영상의 적용등의 많은 분야에 적용된다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.1771-1774
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• 2003

Image segmentation is very important technique as preprocessing. It is used for various applications such as object recognition, computer vision, object based image compression. In this paper, a method which segments the multidimensional image using a hierarchical histogram approach, is proposed. The hierarchical histogram approach is a method that decomposes the multi-dimensional situation into multi levels of 1 dimensional situations. It has the advantage of the rapid and easy calculation of the histogram, and at the same time because the histogram is applied at each level and not as a whole, it is possible to have more detailed partitioning of the situation.