• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.4
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• pp.23-31
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• 2012

This paper proposes a motion estimation-based super resolution algorithm to restore input low-resolution images of large movement into a super-resolution image. It is difficult to find the sub-pixel motion estimation in images of large movement compared to typical experimental images. Also, it has disadvantage which have high computational complexity to find reference images and candidate images using general motion estimation method. In order to solve these problems for the traditional two-dimensional motion estimation using the proposed registration threshold that satisfy the conditions based on the reference image is determined. Candidate image with minimum weight among the best candidates for super resolution images, the restoration process to proceed with to find a new image registration algorithm is proposed. According to experimental results, the average PSNR of the proposed algorithm is 31.89dB and this is better than PSNR of traditional super-resolution algorithm and it also shows improvement of computational complexity.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.67-74
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• 2015

BTC (Block Truncation Coding) image compression is simple to implement by hardware and has excellent edge retention capability of image, image compression techniques are widely used in LCD overdrive. In this paper, to maintain high visual quality and has high compression rate, Multi-Mode BTC (MM-BTC) algorithm is proposed. The MM-BTC has high compression rate using advanced Y-based BTC method and has high visual quality using improved 2-level and 4-level BTC method in this paper. As shown in simulation results, MM-BTC improves still image PSNR (Peak Signal to Noise Ratio) up to 2.34 dB as compared with other algorithms. When the MM-BTC is applied to LCD overdrive, MM-BTC improves moving picture PSNR up to 2.33 dB as compared with other algorithms in literature.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.352-358
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• 2004

This paper is studied the improvement of performance for moving picture encoder using H.263. This is used the new motion vector search algorithm using a relation with neighborhood search point and is applied the integer DCT for the encoder. The integer DCT behaves DCT by the addition operation of the integer using WHT and a integer lifting than conventional DCT that needs the multiplication operation of a floating point number. Therefore, the integer Dn can reduce the operation amount than basis DCT with having an equal PSNR. The new motion vector search algorithm is showed almost similar PSNR as reducing the operation amount than the conventional motion vector search algorithm. To experiment a compatibility of the integer DCT and the conventional DCT, according to result compare case that uses a method only and case that uses the alternate two methods of the integer DCT or the conventional DCT to H.263 encoder and decoder, case that uses the alternate two methods is showed doing not deteriorate PSNR-and being each other compatible visually than case that uses an equal method only.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.59-68
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• 2013

In this paper, an effective scheme was proposed to estimate simple convex surface and simple concave surface which exist in image. This scheme is applied to input image to estimate simple convex surface or simple concave surface. When simple convex surface or simple concave surface exists, another proposed efficient interpolation scheme is used for the interpolated pixel to have the characteristics of simple convex surface or simple concave surface. The magnified image using the proposed schemes is more similar to the real image than the magnified image using the previous schemes. The PSNR values of the magnified images using the proposed schemes are greater than those of the magnified images using the previous interpolation schemes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1359-1368
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• 2021

Steganography is a science of embedding secret data into innocent data and its goal is to conceal the existence of a carrier data. Many research on Steganography has been proposed by various hiding and detection techniques that are based on different algorithms. On the other hand, very few studies have been conducted to analyze the performance of each Steganography software. This paper describes five different Steganography software, each having its own algorithms, and analyzes the difference of each inherent feature. Image quality metrics of Peak Signal to Noise Ratio (PSNR) and Structural SIMilarity (SSIM) are used to define its performance of each Steganography software. We extracted PSNR and SSIM results of a quantitative amount of embedded output images for those five Steganography software. The results will show the optimal steganography software based on the evaluation metrics and ultimately contribute to forensics.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11
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• pp.3150-3156
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• 1999

In this paper, VTQM(Variable Threshold Quantization Method) is proposed, which enhances PSNR by composing the advantages of round-off and truncation quantization methods. From vast experiments, PSNR's of JPEG images with the method are compared with that of standard JPEG methods. At the boundary which affects the compression ratio, VTQM quantizes with a new threshold to reduce the length of compressed data; otherwise, VTQM employs the round-off quantization method to preserve the original image information. As a result, VTQM reduces bit rate while preserving the image quanity. The experimental results show that VTQM enhances PSNR by 0.2-0.3dB., 0.4-0.5dB, with the same bit rate than those of the traditional truncation and round-off quantization methods, respectively.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.167-170
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• 2000

In this paper, we present a fast algorithm for the motion estimation using the efficient selection of an initial search position. In the method, we select the initial search position using the motion vector from the subsmpled images, the predicted motion vector from the neighbor blocks, and the (0,0) motion vector. While searching the candidate blocks, we use the spiral search pattern with the successive elimination algorithm(SEA) and the partial distortion elimination(PDE). The experiment results show that the complexity of the proposed algorithm is about 2∼3 times faster than the three-step search(TSS) with the PSNR loss of just 0.05［dB］∼0.1［dB］ than the full search algorithm PSNR. The search complexity can be reduced with quite a few PSNR loss by controling the number of the depth in the spiral search pattern.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.499-507
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• 2016

Medical imaging techniques such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT) and Ultrasound (US) produce a large amount of digital medical images. Hence, compression of digital images becomes essential and is very much desired in medical applications to solve both storage and transmission problems. But at the same time, an efficient image compression scheme that reduces the size of medical images without sacrificing diagnostic information is required. This paper proposes a novel threshold-based medical image compression algorithm to reduce the size of the medical image without degradation in the diagnostic information. This algorithm discusses a novel type of thresholding to maximize Compression Ratio (CR) without sacrificing diagnostic information. The compression algorithm is designed to get image with high optimum compression efficiency and also with high fidelity, especially for Peak Signal to Noise Ratio (PSNR) greater than or equal to 36 dB. This value of PSNR is chosen because it has been suggested by previous researchers that medical images, if have PSNR from 30 dB to 50 dB, will retain diagnostic information. The compression algorithm utilizes one-level wavelet decomposition with threshold-based coefficient selection.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.410-412
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• 2011

영상 서비스에서 사용자가 시청하는 비디오 화질을 측정하는 것은 사용자의 QoE(Quality of Experience)를 추정할 수 있는 중요한 작업 중 하나이다. 이를 위해 가장 널리 쓰이는 측정 방법 중 PSNR이 있다. PSNR은 원본영상과 시청영상간의 각 픽셀 값의 차이를 계산하여 화질을 측정하는 객관적인 평가 방법이다. 본 논문에서는 객관적 평가 방법인 PSNR에 시청자가 영상 측정 시 느낄 수 있는 시선 인식 집중도를 접목시킨 품질 측정방법을 제안한다. 이는 사용자의 시각적 특성이 고려되기 때문에 보다 사용자에게 맞는 영상 품질을 측정할 수 있게 된다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.80-82
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• 2013

최근 3D의 발전으로 다음 세대의 3D 기술로 디지털 홀로그램을 지목하고 있다. 본 논문에서는 CGH 영상에서 Fresnelet 변환을 통해 주파수 영역에서 각각의 부대역의 특성에 따라 양자화를 다르게 적용하였고, 무손실 부호화인 허프만 코딩을 이용하여 데이터를 압축하는 방법을 제안한다. 실험결과 영상 품질이 다소 열화 되었다는 것을 PSNR 감소를 통해 알 수 있었고, PSNR이 33.50dB인 영상과 원본 영상을 비교하였을 때, 아주 좋은 영상 품직을 갖는 것을 확인 할 수 있었다. 압축률은 PSNR 33.5dB에서 약 50:1의 결과를 보였다.