共查询到19条相似文献,搜索用时 93 毫秒
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本文详细分析了超短脉冲激光电子学全息选通透过散射介质成象系统的噪音因素,其噪音来源主要有电子学全息图的记录过程、再现过程以及CCD自身的噪音、系统光学元件产生的噪音等等,提出了相应的噪音处理措施. 相似文献
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在近场光学扫描显微镜及其它一些以扫描方式成像的系统中,由于图像是逐行扫描而成,因此扫描图像行与行之间存在较大的噪音.针对这种情况及相应的含噪近场光学图像模型,并结合对近场光学扫描图像及其行噪音特点的分析,提出了根据图像行间相关性寻找行噪音补偿因子.同时考虑图像背景波动性选择噪音补偿因子,以此进行行噪音的消除.在此基础上,利用小波变换进一步处理,消除随机起伏噪音.实验结果表明,本方法可以快速有效地去除扫描图像行噪音,且适用于各类扫描图像的处理. 相似文献
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结合小波变换与微分法改善近红外光谱分析精度 总被引:5,自引:2,他引:3
微分法可以有效消除光谱背景和基线漂移,同时会增加光谱噪音;小波变换具有很好的去噪功能,章将微分法和小波变换结合用于重整汽油辛烷值近红外光谱分析。考察了微分噪音对辛烷值分析精度的影响以及小波去噪对微分光谱的噪音扣除以及对辛烷值分析精度改善情况。结果表明,微分光谱可以扣除原始光谱的基线漂移,提高分析精度,同时增加光谱的噪音;噪音对分析精度影响很大。微分光谱经过小波去噪处理后信噪比增加,辛烷值分析精度得到改善。 相似文献
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本文详细分析了超短脉冲激光电子学全息选通透过散射介质成象系统的噪音因素,其噪音来源主要有电子学全息图的记录过程、再现过程以及CCD自身的噪音、系统光学元件产生的噪音等等,提出了相应的噪音处理措施. 相似文献
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对称FIR(有限冲激响应)滤波器的严格的线性相位特性和系统稳定性在数据传输、图像处理等领域得到了广泛的应用。基于单点处理模式的传统数字滤波器能实时处理点信号,但在处理图像、语音等帧信号时,速度较慢,实时性不强。针对这个问题提出了块处理模式的解决方案。通过分析FIR滤波器的原理,设计出基于块处理模式的对称FIR滤波器,并在TMS320C5510芯片中实现。介绍了基于双指针循环寻址的滤波算法,并给出了相应的主要程序。计算机试验仿真表明块处理模式方案提高了帧信号的处理速度,滤波性能良好。 相似文献
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近红外传感器在汽车改造技术中的应用研究 总被引:4,自引:1,他引:3
利用反射式近红外传感器及语音录放组件,研究了汽车倒车防撞语音提示器。当汽车倒车时,只要距车身后尾一定的距离内有人或物体存在,就会有一部分红外光信号经人或物体反射回来,被与发射管同排安装的光敏接收管收到并转换成同频率的电信号后,由模块内部电路进行放大、解调、整形、比较处理后,在输出端输出控制信号,控制语音录放组件工作,告诉司机车后有人、车后有物体。由于近红外线传感器、语音录放组件均为一体化结构,成本低、接线简单、抗震能力强、测量准确、工作稳定可靠,适合在汽车上安装使用。 相似文献
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Corina J. van As-Brooks Florien J. Koopmans-van Beinum Louis C.W. Pols Frans J.M. Hilgers 《Journal of voice》2006,20(3):355-368
SUMMARY: Because of the aperiodicity of many tracheoesophageal voices, acoustic analysis of the tracheoesophageal voice is less straightforward than that of the normal voice. This study presents the development and testing of an acoustic signal typing system based on visual inspection of a narrow-band spectrogram that can be used by researchers for classification of voice quality in tracheoesophageal speech. In addition to this classification system, a selection of acoustic measures [median fundamental frequency, standard deviation of fundamental frequency, jitter, percentage of voiced (%Voiced), harmonics-to-noise ratio (HNR), glottal-to-noise excitation (GNE) ratio, and band energy difference (BED)] was computed to provide more insight into the acoustic components of tracheoesophageal voice quality. For clinical relevance, relationships between the acoustic signal types and an overall judgment of the voice were investigated as well. Results showed that the four acoustic signal types form a good basis for performing more acoustic analyses and give a good impression of the overall quality of the voice. 相似文献
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Two signal-processing algorithms, designed to separate the voiced speech of two talkers speaking simultaneously at similar intensities in a single channel, were compared and evaluated. Both algorithms exploit the harmonic structure of voiced speech and require a difference in fundamental frequency (F0) between the voices to operate successfully. One attenuates the interfering voice by filtering the cepstrum of the combined signal. The other uses the method of harmonic selection [T. W. Parsons, J. Acoust. Soc. Am. 60, 911-918 (1976)] to resynthesize the target voice from fragmentary spectral information. Two perceptual evaluations were carried out. One involved the separation of pairs of vowels synthesized on static F0's; the other involved the recovery of consonant-vowel (CV) words masked by a synthesized vowel. Normal-hearing listeners and four listeners with moderate-to-severe, bilateral, symmetrical, sensorineural hearing impairments were tested. All listeners showed increased accuracy of identification when the target voice was enhanced by processing. The vowel-identification data show that intelligibility enhancement is possible over a range of F0 separations between the target and interfering voice. The recovery of CV words demonstrates that the processing is valid not only for spectrally static vowels but also for less intense time-varying voiced consonants. The results for the impaired listeners suggest that the algorithms may be applicable as components of a noise-reduction system in future digital signal-processing hearing aids. The vowel-separation test, and subjective listening, suggest that harmonic selection, which is the more computationally expensive method, produces the more effective voice separation. 相似文献
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Some effects of talker variability on spoken word recognition 总被引:2,自引:0,他引:2
J W Mullennix D B Pisoni C S Martin 《The Journal of the Acoustical Society of America》1989,85(1):365-378
The perceptual consequences of trial-to-trial changes in the voice of the talker on spoken word recognition were examined. The results from a series of experiments using perceptual identification and naming tasks demonstrated that perceptual performance decreases when the voice of the talker changes from trial to trial compared to performance when the voice on each trial remains the same. In addition, the effects of talker variability on word recognition appeared to be more robust and less dependent on task than the effects of word frequency and lexical structure. Possible hypotheses regarding the nature of the processes giving rise to these effects are discussed, with particular attention to the idea that the processing of information about the talker's voice is intimately related to early perceptual processes that extract acoustic-phonetic information from the speech signal. 相似文献
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本文介绍近30年来水声信号处理领域理论研究的新进展和在声纳设计中的应用。包括水声信号建模、声场匹配、海洋波导和内波现象的探索和研究、声矢量场信息获取和处理,低频水声信道的时/空相关特性,水下目标辐射噪声的不变特征量提取和检测技术,水下语音、图像传输和抗干扰技术。同时概述,声纳设计的前沿领域:大孔径拖曳线列阵声纳、高分辨力合成孔径声纳、深海传呼机等的发展情况。 相似文献
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A. I. Tsyplikhin 《Acoustical Physics》2007,53(1):105-118
An algorithm for estimating the vocal pulse positions and durations in an actual speech signal is described. Testing of the algorithm shows that it outperforms the best of the competitor algorithms in accuracy on the average by a factor of two. The algorithm is less sensitive to spectrum distortions in telephone channels, to various types of noise, and to instability in duration and amplitude of pulses produced by the voice source. The accuracy of the pulse position estimate is sufficient for a synchronous speech signal analysis, while the speed of signal processing makes the algorithm suitable for real-time operation. 相似文献