• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.6A
• /
• pp.464-472
• /
• 2012

In this paper, we propose a new super-resolution algorithm that uses successive frames by applying the block matching motion estimation algorithm. Usually, single frame super-resolution algorithms are based on probability or discrete wavelet transform (DWT) approach to extract high-frequency components of the input image, but only limited information is available for these algorithms. To solve this problem, various multiple-frame based super-resolution algorithms are proposed. The accuracy of registration between frames is a very important factor for the good performance of an algorithm. We therefore propose an algorithm using 6-Tap FIR filter to increase the accuracy of the image registration with sub-pixel unit. Proposed algorithm shows better performance than other conventional interpolation based algorithms such as nearest neighborhood, bi-linear and bi-cubic methods and results in about the same image quality as DWT based super-resolution algorithm.

• Journal of Broadcast Engineering
• /
• v.17 no.3
• /
• pp.480-490
• /
• 2012

When interpolating chrominance signal, the H.264/AVC standard uses linear interpolation. In this paper, we suggest more effective method that uses a high precision filter, 6-tap FIR filter, 2-tap linear filter for chroma interpolation. The experimental result shows that the proposed method achieves the BD-Rate decrease without the PSNR decrease compared with Jm11.0kta2.7. The maximum BD-rate improvements on Y component are 1.3%, those of Cb and Cr components are 19.8%, 25.0%, respectively. The average BD-rate improvements on Y component are 0.5%, those of Cb and Cr components are 6.1%, 6.9%, respectively.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.225-227
• /
• 2009

International standard specification, H.264/SVC improved from H.264/AVC, is set up so as to promote free use of huge multimedia data in various channel environments.;H.264/AVC is a international standard speicification for video compression, adopted and commercialized as standard for DMB broadcasting by JVT of ISO/IEC MPEG and ITU-T VCEG. SVC standard uses 'intra/inter prediction' in AVC as well as 'inter-layer intra prediction', 'inter-layer motion prediction' and 'inter-layer residual prediction' to improve efficiency of encoding. Among prediction technologies, 'inter-layer intra prediction' is to use co-located block of up sampled sublevels as a prediction signal. At this time, application of interpolation is one of the most important factors to determine encoding efficiency. SVC's currently using poly-phase FIR filter of 4-tap and 2-tap respectively to luma components. This paper is written for the purpose of analyzing encoding performance according to the interpolation. For this purpose, we applied poly-phase FIR filter of '2-tap', '4-tap' and '6-tap' respectively to luma components and then measured bit-rate, PNSR and running time of interpolation filter. We're expecting that the analysis results of this paper will be utilized for effective application of interpolation filter. SVC standard uses 'intra/inter prediction' in AVC as well as 'inter-layer intra prediction', 'inter-layer motion prediction' and 'inter-layer residual prediction' to improve efficiency of encoding.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.11a
• /
• pp.106-109
• /
• 2011

본 논문에서는 연속된 프레임을 갖는 영상의 프레임간 움직임 추정 기법을 응용하여 고해상도 영상을 획득하는 초고 해상도 기법을 제안한다. 기존의 단일 영상을 이용한 초고해상도 기법의 경우 영상에서의 고주파 대역을 찾기 위해 확률 기반의 다양한 방법이 제시되었으나 연산에 사용할 수 있는 정보가 제한적이라는 문제가 존재한다. 이러한 문제를 해결하기 위해 연속된 프레임을 이용한 다양한 초고해상도 기법이 제안되었다. 본 논문에서는 주어진 영상의 전, 후의 다수 프레임을 정하여 6-tap FIR(finite impulse response) 필터를 이용하여 프레임들의 부화소(sub-pixel)를 구한 뒤에, 부화소 정밀도의 움직임 추정을 통하여 보다 정확한 고주파성분을 복원하고자 한다. 실험을 통하여 제안하는 기법이 기존의 고등차수(bi-cubic)보간법 보다 선명한 영상을 획득할 수 있었다.

• Proceedings of the IEEK Conference
• /
• summer
• /
• pp.199-203
• /
• 2004

In this paper, we only describe the digital block of two-channel 18-bit analog-to-digital (A/D) converter employing sigma-delta method and xl28 decimation. The device contains two fourth comb filters with 1-bit input from sigma­delta modulator. each followed by a digital half band FIR(Finite Impulse Response) filters. The external analog sigma-delta modulators are sampled at 6.144MHz and the digital words are output at 48kHz. The fourth-order comb filter has designed 3 types of ways for optimal power consumption and signal-to-noise ratio. The following 3 digital filters are designed with 12tap, 22tap and 116tap to meet the specification. These filters eliminate images of the base band audio signal that exist at multiples of the input sample rate. We also designed these filters with 8bit and 16bit filter coefficient to analysis signal-to-noise ratio and hardware complexity. It also included digital output interface block for I2S serial data protocol, test circuit and internal input vector generator. It is fabricated with 0.35um HYNIX standard CMOS cell library with 3.3V supply voltage and the chip size is 2000um by 2000um. The function and the performance have been verified using Verilog XL logic simulator and Matlab tool.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.9
• /
• pp.115-124
• /
• 2004

This paper proposes a high efficient and low power FIR filter chip for partial-response maximum likelihood (PRML) disk drive read channels; it is a 6-bit, 8-tap digital FIR filter. The proposed filter employs a parallel processing architecture and consists of 4 pipeline stages. It uses the modified Booth algorithm for multiplication and compressor logic for addition. CMOS pass-transistor logic is used for low power consumption and single-rail logic is used to reduce the chip area. The proposed filter is actually implemented and the chip dissipates 120mV at 100MHz, uses a 3.3V power supply and occupies 1.88 ${\times}$ 1.38 $\textrm{mm}^2$. The implemented filter requires approximately 11.7% less power compared with the existing architectures that use the similar technology.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.4
• /
• pp.657-665
• /
• 2000

In this study, the bit error rate(BER) performance for the speech and data traffic is evaluated by results of the reverse link simulation of CDMA-based IMT-2000. Simulations in the reverse link are achieved for indoor, pedestrian, and vehicular environments, which are provided by ITU-R . Also, in the these simulations, the fast power control of 1.6kHz rate is applied. The amplitude and phase of the fading signal are estimated by using the 5-tap FIR filter, and the soft-decision Viterbi and Reed-Solomon (RS) decoding are applied. Simulation results provide the optimum ratio of pilot power to traffic power, the BER performance according to the number of fingers, and performance comparison between convolutional code and concatenated code at $10^-6$ BER in 5 MHz system.

• Journal of Broadcast Engineering
• /
• v.10 no.4 s.29
• /
• pp.505-514
• /
• 2005

Image upsampling can be performed in both spatial and frequency (transform) domain. In the spatial domain, various upsampling techniques are developed and 6-tap FIR interpolation filter is most well known method, which is embedded in many video coding standards. It can provide high subjective quality but shows low objective quality. In the transform domain, simple zero padding method can produce upsampled image easily. It shows better objective quality than 6-tap filtering, but it yields ringing effects which annoy eyes. In this paper, we present efficient upsampling method using frequency addition method in transform domain to provide better subjective and objective quality than conventional method Extensive simulation results show that the proposed algorithm produces visually fine images with high PSNR.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.6A
• /
• pp.341-350
• /
• 2003

In this paper, we evaluate the performance of a moving average (MA) channel estimation filter when space-time block coding transmit diversity (STBC-TD) is applied to the wideband direct sequence code division multiple access (WCDMA) forward link. And we present the infinite impulse response (IIR) filter scheme that can reduce the required memory buffer and the channel estimation delay time. This paper also compares the performance between MA filter scheme and IIR filter scheme in various Rayleigh fading channel environments through the bit error rate (BER) and the frame error rate (FER). Extensive computer simulation results show that transmission with STBC-TD provides a significant gain in performance over no transmit diversity technique, particularly at pedestrian speeds. If STBC-TD technique is employed in the channel estimator based on MA filter, it provides considerable performance gains against Rayleigh fading and reduces the optimum filter tap number. Consequently, the channel estimation delay time and the complexity of the receiver are reduced. In addition, the channel estimator based on IIR filter has the advantages such as little memory requirement and no delay time compared to the MA scheme. However, IIR filter coefficients is very sensitive to the mobile speed change and it exerts a serious influence upon the performance. For that reason, it is important to set uP the optimum IIR filter coefficients.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.4C
• /
• pp.363-370
• /
• 2009

Image interpolation addresses the problem of generating a high-resolution image from its low-resolution version. Classical linear interpolation algorithms are simple and popular, but they produce interpolated image with blurred edges and annoying artifacts, Thus, many edge-based interpolation algorithms have been proposed to improve the subjective quality of the interpolated image, especially around edges on the image. In this paper, we propose a new interpolation algorithm which uses edges extracted from binary image. The proposed algorithm is applied to the image after interpolating using 6-Tap FIR filter. The values of interpolation pixels on edges extracted from binary image are modified using neighborhood pixels on the same edge. Experimental results for various images show that the proposed method provides better performance than existing methods.