• The Journal of the Korea Contents Association
• /
• v.15 no.2
• /
• pp.21-30
• /
• 2015

Image coding based on mixed raster content model generates don't care regions (DCR) in foreground and background layers, and its overall coding performance is greatly affected by region filling methods for DCRs. Most conventional methods for DCR filling fail in utilizing the local signal properties in hole regions and thus the high frequency components in non-DCR regions are reflected into DCR after signal filling. In addition, further high frequency components are induced to the filled signal because of signal discontinuities in the boundary of DCR. To solve this problem, a new DCR filling algorithm using the priority-based adaptive region growing is proposed in this paper. The proposed method uses the watershed algorithm and the flooding priority of each pixel for region filling is determined from the degree of smoothness in the neighborhood area. By growing the filled region into DCR based on the computed priority, the expansion of high-textured area can be minimized which can improve the overall coding performance. Experimental results show that the proposed method outperforms conventional algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.3 no.3
• /
• pp.597-605
• /
• 1999

In this paper, we propose a cardioangiography sequence image coding scheme which use a subtraction between initial image and current frame inserted contrast dye. Stable regions are obtained by the multithreshold and meaningful region is extracted by the images with stable region. The image with meaningful region is classified into contour and texture information. Contour information is coded by contour coding. And texture information is approximated by two-dimensional polynomial function and each coefficients is coded. Experimental results confirm that the sequence of cardioangiography are well reconstructed at the low bit rate (0.02∼0.04 bpp) and high compression ratio.

• Journal of Digital Contents Society
• /
• v.17 no.6
• /
• pp.593-601
• /
• 2016

This paper is related to the Region-based Spectral Correlation Estimation(RSCE) coding method that makes it possible to achieve the high-compression ratio by estimating color component images from luminance image. The proposed method is composed of three steps. First, Y/C bit-plane summation image is defined using normalized chrominance summation image and luminance image, and then the Y/C bit-plane summation image is segmented for extracting the shape information of the regions. Secondly, the scale factor and the offset factor minimizing the approximation square errors between luminance image and R, B images by the each region are calculated. Finally, the scale factor and the offset factor for the each region are encoded into bit stream. Referring to the results of computer simulation, the proposed method provides more than two or three times higher compression ratio than JPEG/Baseline or JPEG2000/EBCOT algorithm in terms of bpp needed for encoding two color component images with the same PSNR.

• Journal of KIISE:Software and Applications
• /
• v.34 no.3
• /
• pp.275-302
• /
• 2007

We propose a novel still image compression system which supports a high quality text compression function. The system segments the text from the image and compresses the text with a high quality. The system shows 48:1 high compression ratio using context-based adaptive binary arithmetic coding. The arithmetic coding performs the high compression by the codeblocks in the bitplane. The input of the system consists of a segmentation mode and a ROI(Region Of Interest) mode. In segmentation mode, the input image is segmented into a foreground consisting of text and a background consisting of the remaining region. In ROI mode, the input image is represented by the region of interest window. The high quality text compression function with a high compression ratio shows that the proposed system can be comparable with the JPEG2000 products. This system also uses gray coding to improve the compression ratio.

• Journal of the Korea Computer Industry Society
• /
• v.3 no.9
• /
• pp.1287-1294
• /
• 2002

The algorithm method for progressive image coding based on discrete wavelet transform presented in a paper. After discrete wavelet transform and extract edge information through edge detection, and then designed efficient coding method more then established embedded coding algorithm using expanded EZW algorithm. Generally, edges have a relatively higher influence on image reconstruction. Occurred DWT on image, and can classify significant coefficients and non-significant coefficients. Using property that edge part has appeared significant coefficient in the paper. Especially, we confirmed that higher frequency sub region on DWT image present homogenous direction property. And on embedded coding, which are effective and well-directed information have higher priority to image reconstruction on transmission. Therefore, our technique algorithm system perform better than that of the conventional method such as progressive image coding application.

• Proceedings of the IEEK Conference
• /
• 2003.07e
• /
• pp.2363-2366
• /
• 2003

With the increasing use of multimedia technologies, image compression requires higher performance as well as new features such as embedded Tossy to lossless coding, various progressive order, error resilience and region-of-interest coding. In the specific area of still image encoding, a new standard, the JPEG2000, has been currently developed. This paper presents a new compression scheme based on JPEG2000. In the proposed scheme, gray coding is applied to the wavelet coefficient. Since gray coding produces an image whose bit plane is will clustered. The proposed method improves compression efficiency of the JPEG2000.

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.263-266
• /
• 2003

In this paper, we propose a new progressive image transmission system including the image coding scheme that efficiently uses the relationship between the properties of a spatial image and its wavelet transform. Firstly, an original image is decomposed into several layers by the wavelet transform, and simultaneously decomposed into 2"x2" blocks. Each image is classified into two image types according to the standard deviations of its blocks. And then each block is categorized into two regions by different thresholds according to the image types, i.e., significant activity region (SAR) and insignificant activity region (IAR). Simulation results show that the proposed coding method has better performance than the EZW and SPIHT in terms of image quality and transmitted bit-rate. In addition, it can be applied to the applications requiring the progressive image transmission.nsmission.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.26 no.11
• /
• pp.1867-1871
• /
• 1989

One of the most common problems in pattern recognition and image processing is filling the interior of a region when its contour is given. The existing algorithms of the filling are parity check technique, seeding technique, and technique based on chain coding the boundaries. In this paper, a very simple but effective technique for filling the interior of bounded region is proposed. This algorithm is based on the information of binary-coded boundary direction and covers some of the drawbacks reported in the earlier relevant works.

• Proceedings of the IEEK Conference
• /
• 2003.07e
• /
• pp.2351-2354
• /
• 2003

A new transform coder for arbitrarily shaped image segments is proposed. In the encoder, a block-based DCT is applied to the resulting image block after shifting pixels within the image segment to block border and padding the mean value of the pixels to empty region. For reducing the transmission bit rate, the transform coefficients located in padded region are truncated and only the remaining transform coefficients are transmitted to the decoder. In the decoder, the transform coefficients truncated in the encoder are recovered using received transform coefficients and a block-based inverse DCT is performed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1999.06a
• /
• pp.69-76
• /
• 1999

This paper proposes a new region-oriented coding scheme of still images. The scheme first segments an image into homogeneous regions by making use of Voronoi diagrams. Then luminance components in each Voronoi region are encoded using a transform coding technique which employs the Schmidt's orthogonalization method to produce orthonormal basis-functions for arbitrarily shaped regions. In this technique, coding efficiency depends on the properties of initial vectors to be orthogonalized. Therefore we adaptively select a set of initial vectors as well as the order in which these vectors are orthogonalized. Simulation results indicate that the proposed coding scheme achieves higher coding performance with much less computation than the KLT-based scheme which we reported formerly.