An anti-aliasing filtering of quantum images in spatial domain using a pyramid structure

As a part of quantum image processing,quantum image filtering is a crucial technology in the development of quantum computing.Low-pass filtering can effectively achieve anti-aliasing effects on images.Currently,most quantum image filterings are based on classical domains and grayscale images,and there are relatively fewer studies on anti-aliasing in the quantum domain.This paper proposes a scheme for anti-aliasing filtering based on quantum grayscale and color image scaling in the spatial domain.It achieves the effect of anti-aliasing filtering on quantum images during the scaling process.First,we use the novel enhanced quantum representation(NEQR)and the improved quantum representation of color images(INCQI)to represent classical images.Since aliasing phenomena are more pronounced when images are scaled down,this paper focuses only on the anti-aliasing effects in the case of reduction.Subsequently,we perform anti-aliasing filtering on the quantum representation of the original image and then use bilinear interpolation to scale down the image,achieving the anti-aliasing effect.The constructed pyramid model is then used to select an appropriate image for upscaling to the original image size.Finally,the complexity of the circuit is analyzed.Compared to the images experiencing aliasing effects solely due to scaling,applying anti-aliasing filtering to the images results in smoother and clearer outputs.Additionally,the anti-aliasing filtering allows for manual intervention to select the desired level of image smoothness.

Anti-Aliased Rendering of Water Surface

Water surface is one of the most important components of landscape scenes. When rendering spacious water surface such as that of the lakes and reservoirs, aliasing and/or moire artifacts frequently occur in the regions far from the viewpoint. This is because water surface consists of stochastic water waves which are usually modeled by periodic bump mapping. The incident rays on the water surface are actually scattered by the bumped waves, and the reflected rays at each sample point are distributed in a solid angle. To get rid of the artifacts of moire pattern, we estimate this solid angle of reflected rays and trace these rays. An image-based accelerating method is adopted so that the contribution of each reflected ray can be quickly obtained without elaborate intersection calculation. We also demonstrate anti-aliased shadows of sunlight and skylight on the water surface. Both the rendered images and animations show excellent effects on the water surface of a reservoir.

anti-aliasing是什么意思

在计算机作图或摄影时,如果没有正确地描绘垂直或水平的线段,尤其是采纳数字图像输出,由于有限个的像素格子构成图像这个本质上的性质,在斜线上容易发生锯齿状的不平整现象,习称阶梯效应.

Anti-aliasing nonstationary signals detecion algorithm based on interpolation in the frequency domain using the short time Fourier transform

To eliminate the aliasing that appeared during the measurement of multi-components nonstationary signals, a novel kind of anti-aliasing algorithm based on the short time Fourier transform （STFT） is brought forward. First the physical essence of aliasing that occurs is analyzed; second the interpolation algorithm model is setup based on the Hamming window; then the fast implementation of the algorithm using the Newton iteration method is given. Using the numerical simulation the feasibility of algorithm is validated. Finally, the electrical circuit experiment shows the practicality of the algorithm in the electrical engineering.

An Anti-aliasing Algorithm Suitable to Map Publishing Symbol

On the basis of analysis of various algorithms, an anti-aliasing algorithm called brush method was presented, which is suitable to map publishing symbol. After introducing the basic principle and implementation of brush method in detail, the result and efficiency were evaluated through experiments.

AN ANTI-ALIASING FILTER FOR ∑△ ADC

An anti-aliasing filter for ADCs using a combination of active RC and analog FIR filters is presented in this letter. The first order active RC filter is set at 100kHz to minimize the die size and variations of linear phase and gain in 0-4kHz passband. The 2-tap FIR filter provides more than -53dB attenuation at 2MHz +4kHz frequency range. The proposed filter achieved more than -76dB attenuation at sampling frequency with +0.01 phase linearity and +0.02dB gain variation within 0-4kHz bandwidth. The active die area of the fully differential filter is 0.17mm2 in 0.5um CMOS technology. The experimental and simulation results have been obtained and the feasibility of the proposed method is shown.

An efficient spatial anti-aliasing method for deferred shading

In recent years, image-based anti-aliasing techniques have been widely investigated in real-time computer graphics. Compared to traditional routine of anti-aliasing, image-based methods, which combined with deferred shading, can efficiently decouple anti-aliasing step from standard graphics pipeline. However, most of the existing image-based methods consume video memory, bandwidth and computation resources heavily. In this paper, we propose an optimized anti-aliasing method, which can efficiently reduce the multi-sampling rate by a multi-sampling mask. We carefully designed the rendering system to avoid serial execution on branch divergence, by utilizing both modern GPU’s features and latest shader model. Experimental results demonstrate that our method can achieve high-quality synthesized image with real-time performance.

Tunable-Q contourlet transform for image representation

A novel tunable-quality-factor （tunable-Q） contourlet transform for geometric image representation is proposed. The Laplacian pyramid in original contourlet decomposes a signal into channels that have the same bandwidth on a logarithmic scale, and is not suitable for images with different behavior in frequency domain. We employ a new tunable-Q decomposition defined in the frequency domain by which one can flexibly tune the bandwidth of decomposition channels. With an acceptable redundancy, this tunable-Q contourlet is also anti-aliasing and its basis is sharply localized in the desired area of frequency and spatial domain. Our experiments in nonlinear approximation and denoising show that the contourlet using a better-suitable quality factor can achieve a more promising performance and often outperform wavelets and the previous contourlets both in visual quality and in terms of peak signal-to-noise ratio.

A Method of Peak Detecting for Nanosecond Pulse in Optical Performance Monitoring System

In optical performance monitoring system,the analog to digital converter is needed to detect the peak of nanosecond pulse and get the signal envelope.A scheme based on a designed anti-aliasing filter and analog to digital converter is proposed to broaden the nanosecond pulse and make it easier for the analog to digital converter to catch the peak of the nanosecond pulse.The experimental results demonstrate that,with the proposed scheme,the optical performance system needs less time to get the recovered eye-diagram of high speed optical data signal,and is robust to phase mismatch in the analog to digital converter circuit.

为X800开启自适应抗锯齿

随着ATI Radeon X1000的发布，ATI也将一种新的抗锯齿技术——Adaptive Anti-Aliasing（自适应抗锯齿，简称AAA）推向了前台，X1000以上显示的用户可凭此享受到较低分辨率下的好画质，减少画面中的锯齿，事实上，AAA并非是X1000以上显卡的专利，它早已潜伏在ATI催化剂驱动之中，只要你找到合适的方法，X800显卡甚至更低端的显卡一样能享受到这项技术带来的画质改善，移花接木，并非不可能……

Feedback Filtering for Digital Control Applications

Thanks to the progress in semiconductor technologies, today microcontrollers offer huge computational power. That allows using advanced control algorithms with a built-in intelligence with a sufficient speed, for many demanding applications. These capabilities make the embedded control ideal for using at complex plants and for obtaining the highest performance in a wide area of operations. However, control performance also strongly depends on the feedback. A short latency and a high precision of embedded analog peripherals allow building fast and accurate control loops. The paper proposes an easy design method of high performance analog to digital converter filtering path, optimized for control applications.

Super-Resolution with Multiselective Contourlets

We introduce a new approach to image super-resolution. The idea is to use a simple wavelet-based linear interpolation scheme as our initial estimate of high-resolution image;and to intensify geometric structure in initial estimation with an iterative projection process based on hard-thresholding scheme in a new angular multiselectivity domain. This new domain is defined by combining of laplacian pyramid and angular multiselectivity decomposition, the result is multiselective contourlets which can capture and restore adaptively and slightly better geometric structure of image. The experimental results demonstrate the effectiveness of the proposed approach.

丽台nVIDIA Quadro FX4500 X2双GPU专业显卡上市

丽台科技针对专业显卡市场推出了nVIDIA Quadro FX4500 X2专业级显卡。它配备1024MB GDDR3显存、四个Dual-link DVI-1输出接口以及一个3D立体眼镜输出、可支持nVIDIA SLi技术并可与SDI或G-Sync输出子卡搭配实时满足电影特效．影视制作．工业设计的需求。此外，配备双GPU的Ouadro FX4500 X2显卡除提供强大的绘图性能与超高影像质量之外．32倍全景反锯齿技术（Full—Scene Anti-aliasing．FSAA）亦可显著提升色彩准确性和边缘／线条的图形质量。

混叠和抗混叠技术

操作Photoshop或其它图像处理软件时经常要对是否启用Anti-aliasing这一功能作出选择。Aliasing一词指数字图像信号的频率混叠现象,它可能因原稿数字化时采样间隔过大而产生,也可能产生于图像的重新采样操作(比如放大或缩小图像,选择部分图像后的裁剪或粘贴操作)。此外。

“偷取”X1000新功能

上一期笔者为大家介绍了ATi X1000系列显卡的应用技巧，在文中曾提到过“Adaptive Anti-Aliasing（自适应反锯齿，下文将简称为AAA）”这一功能，估计有很多朋友都对它比较感兴趣吧？这么好的东西岂能让X1000系列显卡的用户独享，下面笔者就以RadeonX800 Pro显卡为例来告诉大家如何“偷取”AAA功能，让老显卡也玩玩新东西（Radeon9600以上的显卡均可支持该功能）。

Review:Image anti-aliasing techniques for Internet visual media processing: a review

Anti-aliasing is a well-established technique in computer graphics that reduces the blocky or stair-wise appearance of pixels. This paper provides a comprehensive overview of the anti-aliasing techniques used in computer graphics, which can be classified into two categories: post-filtering based anti-aliasing and pre-filtering based anti-aliasing. We discuss post-filtering based anti-aliasing algorithms through classifying them into hardware anti-aliasing techniques and post-process techniques for deferred rendering. Comparisons are made among different methods to illustrate the strengths and weaknesses of every category. We also review the utilization of anti-aliasing techniques from the first category in different graphic processing units, i.e., different NVIDIA and AMD series. This review provides a guide that should allow researchers to position their work in this important research area, and new research problems are identified.

Temporal and spatial anti-aliasing for rendering reflections on water waves

The reflection of a bright light source on a dynamic surface such as water with waves can be difficult to render well in real time due to reflection aliasing and flickering.In this paper,we propose a solution to this problem by approximating the reflection direction distribution for the water surface as an elliptical Gaussian distribution.Then we analytically integrate the reflection contribution throughout the rendering interval time.Our method can render in real time an animation of the time integrated reflection of a spherical light source on highly dynamic waves with reduced aliasing and flickering.

A method for estimating the errors in many-light rendering with supersampling

In many-light rendering, a variety of visual and illumination effects, including anti-aliasing,depth of field, volumetric scattering, and subsurface scattering, are combined to create a number of virtual point lights(VPLs). This is done in order to simplify computation of the resulting illumination. Naive approaches that sum the direct illumination from many VPLs are computationally expensive;scalable methods can be computed more efficiently by clustering VPLs, and then estimating their sum by sampling a small number of VPLs. Although significant speed-up has been achieved using scalable methods, clustering leads to uncontrollable errors, resulting in noise in the rendered images. In this paper, we propose a method to improve the estimation accuracy of manylight rendering involving such visual and illumination effects. We demonstrate that our method can improve the estimation accuracy by a factor of 2.3 over the previous method.