EFFECTS OF UNDERSAMPLING ON THE PROPER INTERPRETATION OF MODULATION TRANSFER-FUNCTION, NOISE POWER SPECTRA, AND NOISE EQUIVALENT QUANTA OF DIGITAL IMAGING-SYSTEMS
EFFECTS OF UNDERSAMPLING ON THE PROPER INTERPRETATION OF MODULATION TRANSFER-FUNCTION, NOISE POWER SPECTRA, AND NOISE EQUIVALENT QUANTA OF DIGITAL IMAGING-SYSTEMS
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DOI：
10.1118/1.597600
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发表时间：
1995-02-01
期刊：
影响因子：
3.8
通讯作者：
DOBBINS, JT
中科院分区：
文献类型：
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作者：
DOBBINS, JT
当系统被欠采样时，对数字系统中调制传递函数（MTF）、噪声功率谱（SNR）和噪声等效量子（NEQ）的正确理解会受到严重阻碍。采样不足会导致三个显著的并发症：（1）MTF和MTF分别不表现为单个正弦曲线的传递幅度和方差，（2）数字系统对δ函数的响应不是空间不变的，因此不满足经典分析的某些技术要求，以及（3）NEQ在特定频率下失去其作为最大可用SNR 2（信噪比）的常见含义。这三个复杂性导致欠采样数字系统之间的MTF和NEQ的比较取决于正在评估的图像的频率内容。本教程介绍了数字系统的MTF、SNR和NEQ概念，沿着了对上述欠采样并发症的完整理论处理。
The proper understanding of modulation transfer function (MTF), noise power spectra (NPS), and noise equivalent quanta (NEQ) in digital systems is significantly hampered when the systems are undersampled. Undersampling leads to three significant complications: (1) MTF and NPS do not behave as transfer amplitude and variance, respectively, of a single sinusoid, (2) the response of a digital system to a delta function is not spatially invariant and therefore does not fulfill certain technical requirements of classical analysis, and (3) NEQ loses its common meaning as maximum available SNR2(signal‐to‐noise) at a particular frequency. These three complications cause the comparisons of MTF and NEQ between undersampled digital systems to depend on the frequency content of the images being evaluated. A tutorial of MTF, NPS, and NEQ concepts for digital systems is presented, along with a complete theoretical treatment of the above‐mentioned complications from undersampling.