• Journal of the Korean Graphic Arts Communication Society
• /
• v.21 no.1
• /
• pp.35-44
• /
• 2003

Because of computer developing, the digital image making the use of many a field of application with - web-above, electronic publishing. printing, dynamic image management and photo CD production etc., however many problems of save and management. The management image use of compression moth which don't have a affect on image, reduce file size. A study used sequential DCT0based mode and progressive DCT-based mode of JPEG(Joing Photographic Experts Group) compression method and Wavelet compression method. Therefore, the analog image and digital image was changed and applied by several stages according to compression rate. It made inquiries of the optimum compression rate that be compared quality transformation between original image and compressed image. As compression image was printing simply, the quality was studied by subjective valuation method, that was studied propriety and usefulness.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.825-828
• /
• 2022

In this paper, we propose an efficient image size selection method for video-based point cloud compression. The current MPEG video-based point cloud compression reference encoding process configures a threshold on the size of images while converting point cloud data into images. Because the converted image is compressed and restored by the legacy video codec, the size of the image is one of the main components in influencing the compression efficiency. If the image size can be made smaller than the image size determined by the threshold, compression efficiency can be improved. Here, we studied how to improve the compression efficiency by selecting the best-fit image size generated during video-based point cloud compression. Experimental results show that the proposed method can reduce the encoding time by 6 percent without loss of coding performance compared to the test model 15.0 version of video-based point cloud encoder.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.5
• /
• pp.31-40
• /
• 2016

In this paper, we analyse the characteristics of the edge image and propose a new entropy coding optimized to the compression of the edge image. The pixel values of the edge image have the Gaussian distribution around '0', and most of the pixel values are '0'. By using this analysis, the Zero Block technique is utilized in spatial domain. And the Intra Prediction Mode of the edge image is similar to the mode of the surrounding blocks or likely to be the Planar Mode or the Horizontal Mode. In this paper, we make use of the MPM technique that produces the Intra Prediction Mode with high probability modes. By utilizing the above properties, we design a new entropy coding method that is suitable for edge image and perform the compression. In case the existing compression techniques are applied to edge image, compression ratio is low and the algorithm is complicated as more than necessity and the running time is very long, because those techniques are based on the natural images. However, the compression ratio and the running time of the proposed technique is high and very short, respectively, because the proposed algorithm is optimized to the compression of the edge image. Experimental results indicate that the proposed algorithm provides better visual and PSNR performance up to 11 times than the JPEG.

• The KIPS Transactions:PartB
• /
• v.13B no.3 s.106
• /
• pp.231-238
• /
• 2006

In this paper, the method to make lossless image compression that holds considerable part of total volume of mobile game has been proposed. To increase the compression rate, we compress the image by Deflate algorithm defined in RFC 1951 after reorganize it at preprocessing stage before conducting actual compression. At the stage of preprocessing, we obtained the size of a dictionary based on the information of image which is the feature of Dictionary-Based Coding, and increased the better compression rate than compressing in a general manner using in a way of restructuring image by pixel packing method and DPCM prediction technique. It has shown that the method increased 9.7% of compression rate compare with existing mobile image format, after conducting the test of compression rate applying the suggested compression method into various mobile games.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.7
• /
• pp.3245-3271
• /
• 2016

To obtain well-dehazed images at the receiver while sustaining low bit rates in the transmission pipeline, this paper investigates the effects of image dehazing methods using dehazing contrast-enhancement filters on image compression for surveillance systems. At first, this paper proposes a novel image dehazing method by using a new method of calculating the transmission function—namely, the direct denoising method. Next, we deduce the dehazing effects of the direct denoising method and image dehazing method based on dark channel prior (DCP) on image compression in terms of ringing artifacts and blocking artifacts. It can be concluded that the direct denoising method performs better than the DCP method for decompressed (reconstructed) images. We also improve the direct denoising method to obtain more desirable dehazed images with higher contrast, using the saliency map as the guidance image to modify the transmission function. Finally, we adjust the parameters of dehazing contrast-enhancement filters to obtain a corresponding composite peak signal-to-noise ratio (CPSNR) and blind image quality assessment (BIQA) of the decompressed images. Experimental results show that different filters have different effects on image compression. Moreover, our proposed dehazing method can strike a balance between image dehazing and image compression.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 1997.11a
• /
• pp.91-101
• /
• 1997

The demand for handling images in digital form has increased dramatically in recent years. Digital image compression is required to store and transmit mass information in different from general information. JPEG(Joint Photographic Experts Group) committee founded by CCITT and ISO is define the still-image standard compression/restoration algorithm. JPEG is proposed the standard of grayscale and color still-image compression/restoration. In the image quality, JPEG is applicable to the various applications in which compression is able to from 1/10 to 1/50 without the visible obstacle. In this paper, we proposed that the proposed method enhance the compression ratio which is reducing the higher frequency in order to increasing the spatial redundancy in the image. The proposed method is using the low pass filter in order to reducing the higher frequency. The low-pass filters are using the median filter and convolution filter in the spatial domain, FFT filter in the frequency domain. We acquired the additive compression ratio reducing the higher frequency using the low-pass filter.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.282-285
• /
• 2006

This paper analyzed the characteristics of the Lossy JPEG of the meteorological satellite image, and analyzed the quality of the Lossy JPEG compression, which is proper for the LRIT(Low Rate Information Transmission) to be serviced to the SDUS(Small-scale Data Utilization Station) system of the COMS(Communication, Oceans, Meteorological Satellite). Since COMS is to start running after 2008, we collected the data of the MTSAT-1R(Multi-functional Transport Satellite -1R) for analysis, and after forming the original image to be used to LRIT by each channel and time zone of the satellite image data, we set the different quality with the Lossy JPEG compression, and compressed the original data. For the characteristic analysis of the Lossy JPEG, we measured PSNR(Peak Signal to Noise Rate), compression rate and the time spent in compression following each quality of Lossy JPEG compression. As a result of the analysis of the satellite image data of the MTSAT-1R, the ideal quality of the Lossy JPEG compression was found to be 90% in the VIS Channel, 85% in the IR1 Channel, 80% in the IR2 Channel, 90% in the IR3 Channel and 90% in the IR4 Channel.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.88-88
• /
• 2002

Satellite Image archiving system requires large storage and long transmission time. A simple and cheap way of overcoming these limitations is to increase the compression ratio. However this requires a feasibility study for accurate applications. Here, a new still image compression standard is being developed, the JPEG2000. It provides lossless and lossy compression, progressive transmission by pixel accuracy and by resolution, region-of-interest coding, user-defined tiling size, random codestream access and processing etc. In this study, we will briefly introduce the JPEG2000 compression standard which provides a new compression technique based on the wavelet technology and offers better compression ratios, and evaluate the compression ratios of JPEG2000 for satellite image by performing various image quality tests. Also, we will compare brief test result using the commercial remote sensing software.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.49 no.10
• /
• pp.135-141
• /
• 2012

To reduce frame memory size usage in LCD overdrive, block truncation coding (BTC) image compression is commonly used. For maximization of compression ratio, BTC image compression is need to compress bitmap or quantization data. In this paper, for high compression ratio, we propose CMBQ-BTC (CMBQ : compression method bitmap data and quantization data) algorithm. Experimental results show that proposed algorithm is efficient as compared with PSNR and compression ratio of the conventional BTC method.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.491-494
• /
• 1999

Introduction of digital communication network such as Integrated Services Digital Networks(ISDN) and digital storage media have rapidly developed. Due to a large amount of image data, compression is the key techniques in still image and video using digital signal processing for transmitting and storing. Digital image compression provides solutions for various image applications that represent digital image requiring a large amount of data. In this paper, the proposed DWT(Discrete Wavelet Transform) filter bank is consisted of simple architecture, but it is efficiently designed that a user obtain a wanted compression rate as only input parameter. If it is implemented by FPGA chip, the designed encoder operates in 12MHz.