• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.4
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• pp.101-110
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• 1996

Color image quantization is a process of selecting a set of colors to display an image with some representative colors without noticeable perceived difference. It is very important in many applications to display a true color image in a low cost color monitor or printer. the basic problem is how to display 224 colors with 256 or less colors, called color palette. In this paper, we propose an algorithm to design the 256 or less size color palette by using spatial maskin geffect of HVS and subjective distortion measure weighted by color palette by using spatial masking effect of HVS and subjective distortion measure weighted by color activity in 4*4 local region in any color image. The proposed algorithm consists of octal prequantization and subdivision quantization processing step using the distortion measure and modified Otsu's between class variance maximization method. The experimental results show that the proposed algorithm has higher visual quality and needs less consuming time than conventional algorithms.

• The KIPS Transactions:PartB
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• v.10B no.5
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• pp.535-542
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• 2003

This study is concerned with an assistive technology which reduces color blinds´s confusion when they access electronic documents including color objects in their computers. In this study, 1 restrict the assistive technology would apply to windows operating system, 256 color mode and implement to minimize color distortion which occurs in multi window environments because of color approximation process. As a basic palette, I use a 216 colors web safe palette which the Christine proposed as a standard for color blind, expand it to 256 colors to apply all computer displays using Microsoft Windows as its operating system and implement it as windows application. To test its effectiveness, I use a simulator for dichromats, as results of the test, the developed color vision deficiency correction S/W is effective to reduce the confusion. It is more effective to use the implemented S/W in both of design and client process for electronic documents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.35-43
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• 2005

This paper introduces a new algorithm to improve compression performance of 256 color images called palette-based or indexed images. The proposed scheme counts each frequency of index values after present index value and determines each rank for every index value by sorting them in descending order. Then, the scheme makes ranked index image instead of original indexed image using the way to replace index values with ranks. In the ranked index image's distribution produced as a result of this algorithm, the higher ranked index value, the more present same values. Therefore, data redundancy will be raised and more efficient performance of compression can be expected. Simulation results verify that because of higher compression ratio by up to 22.5, this newly designed algorithm shows a much better performance of compression in comparison with the arithmetic coding, intensity-based JPEG-LS and palette-based GIF.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.255-256
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• 2005

For the students who specialize in interior design irrespective of their color susceptibility, it is prerequisite to precede a systematic curriculum in the first place on how to put the color theory to practical use. Therefore, this curriculum has its purpose to let the students study on how to put to practical use of their understanding of color as one of the finishing materials for interior design. The 16-weekschool days has been segmented into a theoretical study and practical training, This thesis has summed up the basic instance of the color theory, the first of the three basicpractical courses and presented its results to the students. In due course of this curriculum, the students were recommended to pick up one photo image of their selection out of which they could make out color palette based on their analysis of the photo image, so that they could study on how to apply their color palette to a three dimensional space. Firstly, through this course, they could experience the process for a color image that they had so far sensed subjectively and vaguely to become an objective inevitable result. Secondly, they studied on the process of how a two-dimensionalcolor image could be applied for a three-dimensional space. It is significant of this curriculum in the sense that the students become prepared through this study course with essential knowledge applicable to various interior designs in their future.

• The KIPS Transactions:PartB
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• v.11B no.1
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• pp.21-26
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• 2004

Color image quantization is a process of selecting a set of colors to display an image with some representative colors without noticeable perceived difference. It is very important in many applications to display a true color image in a low cost color monitor or printer. The basic problem is how to display 256 colors or less colors, called color palette, In this paper, we propose improved binary tree vector quantization based on spatial sensitivity which is one of the human visual properties. We combine the weights based on the responsibility of human visual system according to changes of three Primary colors in blocks of images with the process of splitting nodes using eigenvector in binary tree vector quantization. The test results show that the proposed method generates the quantized images with fine color and performs better than the conventional method in terms of clustering the similar regions. Also the proposed method can get the better result in subjective quality test and WSNR.