• The KIPS Transactions:PartB
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• v.14B no.5
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• pp.321-328
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• 2007

In this paper, we propose a fast and dynamic Region-of-Interest coding method using the adaptive code-block discrimination algorithm in JPEG2000 images which complements the implicit ROI coding method and the modified implicit ROI coding method. For reducing the time of discriminating the code block, the proposed method estimates the characteristics of the shape of ROI and makes the shape of boundaries, and classifies the patterns of each code block. The method improves the preferred processing and loss of wavelet coefficients of background within the ROI code blocks by adaptively classifying the code blocks with the percentage of content of the wavelet coefficients using the thresholds of ROI and background. Also, the priority control of wavelet coefficients of background within ROI code block supports the rapid ROI coding by processing in batch based on patterns unlike the existing methods that process with unit of wavelet coefficients. To show the usefulness of this method, we compared this to the existing methods. There is no difference in performance, but we confirmed very speedy in processing time.

• Journal of Korea Multimedia Society
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• v.11 no.1
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• pp.13-22
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• 2008

This paper proposes an efficient ROI code block discrimination algorithm for dynamic ROI coding. The proposed algorithm calculates the girth of the ROI only with some mask information in consideration of the characteristics of the shape of the ROI for reducing a ROI code block discrimination time, and this proposed algorithm discriminates whether there is a ROI code block by the girth and the critical value of the ROI. Also, this discrimination algorithm is capable of treating the coefficients of the background within a ROI code block preferentially and controlling a loss by controlling the threshold value of the ROI. In order to demonstrate the utility of the proposed method, this paper conducted a comparative experiment of the proposed method with the existing methods. As a result of this experiment, it was confirmed that the proposed method was superior to the conventional methods in terms of quality and speed.

• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.63-71
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• 2009

In this study, we propose a revised dynamic ROI (Region-of-Interest) coding method in which the focused ROI is automatically extracted without help from users during the recovery process of low DOF (Depth-of-Field) JPEG2000 image. The proposed method creates edge mask information using high frequency sub-band data on a specific level in DWT (Discrete Wavelet Transform), and then identifies the edge code block for a high-speed ROI extraction. The algorithm scans the edge mask data in four directions by the unit of code block and identifies the edge code block simply and fastly using a edge threshold. As the results of experimentation applying for Implicit method, the proposed method showed the superiority in the side of speed and quality comparing to the existing methods.

• The KIPS Transactions:PartB
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• v.18B no.6
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• pp.349-354
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• 2011

In ROI processing of JPEG2000, a region of large image indicated by the user must be processed preferentially, because it takes a considerable amount of time to display the full image. When the user indicates a region of the outlined image, then the browser masks the region and sends the mask information to the server that transmitted the outlined image. The server that receives the mask information preferentially sends the corresponding code blocks. Here, a quick generation of mask information is important. In this paper, we use 48 predefined mask patterns, which are defined according to the distribution shape of ROI and background to reduce the computing time. As a result, compared to other methods that precisely handles the ROI and background, the processing time of the method is remarkably reduced, but the quality is short of the existing methods just a little bit.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.81-89
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• 2009

To support dynamic Region-of-Interest(ROI) in JPEG2000, a fast ROI mask generation is needed. In the existing methods of ROI coding, after scanning all the pixels in order and discriminating ROI, an ROI mask has been generated. Our method scans 4 pixels of the corners in one code block, and then based on those informations, scans the edges from the corners to get the boundaries of ROI and background. These informations are consisted of a distributed information of ROI and two coordinates of the pixels, which are the points the edges and the boundaries meet. These informations are transmitted to encoder and supported for fast ROI mask generation. There were no great differences between the proposed method and the existing methods in quality, but the proposed method showed superiority in speed.

• The KIPS Transactions:PartB
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• v.17B no.6
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• pp.421-428
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• 2010

It takes a long time for the users to view a whole image from the image server under the low-bandwidth internet environments or in case of a big sized image. In this case, as there needs a technique that preferentially transfers a part of image, JPEG2000 offers a ROI(Region-of-Interest) coding. In ROI coding, the users see the thumbnail of image from the server and specifies some regions that they want to see first. And then if an information about the regions are informed to the server, the server preferentially transfers the regions of the image. The existing methods requested a huge time to compute the mask information, but this thesis approximately computes the regions and reduces the creating time of the ROI masks. If each code block is a mixed block which ROI and background are mixed, the proper boundary points should be acquired. Searching the edges of the block, getting the two points on the edge, to get the boundary point inside the code block, the method searches a mid point between the two edge points. The proposed method doesn't have a big difference compared to the existing methods in quality, but the processing time is more speedy than the ones.