• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2372-2382
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• 1998

In this paper, we propose a new edge based finite state vector quantization method having better performance than conventional side-match finite state vector quantization. In our proposed scheme, each dCT transformed block is classified to 17 classes according to edge types. Each class has a different codebook based on its characteristis. Encoder classified each block to motion block or stationary block and constructed a merging map by using edge and motion information, and sent to decoder. We controled amoutn of bing bits transmitted with selecting modes accoridng to bandwidth of transmitting channel. Compared with conventional algorithms, H.263 and H.261 at low bit rate, our proposed algorithm shows better picture quality and good performance.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.178-180
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• 2004

In this work, we propose new method of sigma filtering for efficient filtering and preserving edge regions in DCT Domain. In block-based image compression technique, the image is first divided into non-overlapping $8{\times}8$ blocks. Then, the two-dimensional DCT is computed for each $8{\times}8$ block. Once the DCT coefficients are obtained, they are quantized using a specific quantization table. Quantization of the DCT coefficients is a lossy process, and in this step, noise is added. In this work, we combine IDCT matrix and filter matrix to a new matrix to simplify filtering process to remove noise after IDCT in spatial domain, for each $8{\times}8$ DCT coefficient block, we determine whether this block is edge or homogeneous region. If this block is edge region, we divide this $8{\times}8$ block into four $4{\times}4$ sub-blocks, and do filtering process for sub-blocks which is homogeneous region. By this process, we can remove blocking artifacts efficiently preserving edge regions at the same time.

• The Journal of Korea Robotics Society
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• v.5 no.2
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• pp.85-92
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• 2010

In this paper, we propose a digital image stabilization technique using edge detection and Lucas-Kanade optical flow in order to minimize the motion of the shaken image. The accuracy of motion estimation based on block matching technique depends on the size of search window, which results in long calculation time. Therefore it is not applicable to real-time system. In addition, since the size of vector depends on that of block, it is difficult to estimate the motion which is bigger than the block size. The proposed method extracts the trust region using edge detection, to estimate the motion of some critical points in trust region based on Lucas-Kanade optical flow algorithm. The experimental results show that the proposed method stabilizes the shaking of motion image effectively in real time.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.231-234
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• 2002

This paper proposes a new approach to extract contour of moving object from compressed video stream. We segment the area of moving object by using motion vector and extract the motion object block from it. And then we describe the connectivity direction of outline moving block, detect the edge related to connectivity direction in the block and finally obtain the contour by connecting the edges. This can divide the moving object only with motion vector and detect the exact contour on the basis of the edge automatically. Also, we can reduce spending time using motion block and remove the noise with directional edge. The experimental results demonstrate the accurate and effective qualify of the proposed method.

• The Journal of Information Technology
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• v.6 no.1
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• pp.71-84
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• 2003

In this paper, it is presented the efficient system for data recognition using the proposed binary code images. The proposed algorithm finds the position of binary image. Through the process of the block region classification, it is classified each block with the edge region using the value of gray level only. Each block region is divided horizontal and vertical edge region. If horizontal edge region blocks are classified over six blocks in any region, the proposed algorithm should search the vertical edge region in the start point of the horizontal edge region. If vertical edge region blocks were found over ten blocks in vertical region, the code image would found. Practical code region is acquired from the rate of the total edge region that is computed from the binary image that is processed with the average value. In case of the wrong rate, it is restarted the code search in the point after start point and the total process is followed. It has a short time than the before process time because it had classified block information. The block processing is faster thant the total process. The proposed system acquires the image from the digital camera and makes binary image from the acquired image. Finally, the proposed system extracts various characters from the binary image.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.569-571
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• 1998

In this paper, we propose a method of restoring blurred images by an edge-sensitive adaptive filter. The direction of the edge is estimated using the properties of 2-D block FFT. Reduction of blurring due to the added noise during image transfer and the focus of lens caused by shooting a fast moving object is very important. To remove this phenomenon effectively, we can use the edge information obtained by processing the blurred images. The proposed algorithm estimates both the existence and the direction of the edge. On the basis of the acquired edge direction information, we choose the appropriate edge-sensitive adaptive filter, which enables us to get better images than images obtained by methods not considering the direction of the edge. The performance of the proposed algorithm is shown in the simulation result.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.8
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• pp.63-72
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• 2012

In this paper, we proposed a parallel architecture of line & block edge filter for high-performance H.264/AVC deblocking filter for Quad Full High Definition(Quad FHD) video real time processing. To improve throughput, we designed 4-parallel block edge filter with 16 line edge filter. To reduce internal buffer size and processing cycle, we scheduled 4-parallel zig-zag scan order as deblocking filtering order. To avoid data conflicts we placed 1 delay cycle between block edge filtering. We implemented interleaving buffer, as internal buffer of block edge filter, to sharing buffer for reducing buffer size. The proposed architecture was simulated in 0.18um standard cell library. The maximum operation frequency is 108MHz. The gate count is 140.16Kgates. The proposed H.264/AVC deblocking filter can support Quad FHD at 113.17 frames per second by running at 90MHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11C
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• pp.662-672
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• 2011

This paper presents a new edge-preserving algorithm and its VLSI architecture for block artifact reduction. Unlike previous approaches using block classification, our algorithm utilizes pixel classification to categorize each pixel into one of two classes, namely smooth region and edge region, which are described by the edge-preserving maps. Based on these maps, a two-step adaptive filter which includes offset filtering and edge-preserving filtering is used to remove block artifacts. A pipelined VLSI architecture of the proposed deblocking algorithm for HD video processing is also presented in this paper. A memory-reduced architecture for a block buffer is used to optimize memory usage. The architecture of the proposed deblocking filter is prototyped on FPGA Cyclone II, and then we estimated performance when the filter is synthesized on ANAM 0.25 ${\mu}m$ CMOS cell library using Synopsys Design Compiler. Our experimental results show that our proposed algorithm effectively reduces block artifacts while preserving the details.

• Journal of Korea Multimedia Society
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• v.6 no.1
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• pp.78-88
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• 2003

A novel adaptive error concealment technique is proposed using a variable operating region algorithm based on MPEG-4 coding. In the algorithm, a missing block is classified as flat or edge block based on local information from the surrounding blocks extracted using a Sobel operation in a variable operating region (VOR). In this case, the VOR is determined adaptively according to the number of edge directions in the missing block. 1;sing the classification, the flat blocks are then concealed by the Proposed mean based weighted bilinear interpolation (MWBLI) method, and the edge blocks by the boundary directional interpolation (BDI) method. Consequently, the use of the Proposed VOR improves the subjective performance in a curved edge region, while the adaptive processing based on block classification improves the objective performance. Experimental results confirmed that the proposed algorithm produced better results than conventional algorithms, both subjectively and objectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2C
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• pp.121-128
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• 2003

In this paper, we propose a new disparity estimation method called object based block matching algorithm(OBMA) for stereoscopic images which is able to reduce the blocking artifact. In the proposed algorithm, edge information of the given image is first extracted and then we estimate the disparity of each segmented object to remove the blocking artifact. In the experimental results, it is proven that the proposed algorithm has about the same performance as the old BMA algorithm while it achieves much better subjective quality.