ผลต่างระหว่างรุ่นของ "ความถี่เชิงพื้นที่"

* {{cite web | url = http://www.haberdar.org/Spatial-Frequency-of-an-Image-Tutorial.htm | title = Tutorial: Spatial Frequency of an Image | publisher = Hakan Haberdar, University of Houston | accessdate = 2012-03 | archive-date = 2016-12-04 | archive-url = https://web.archive.org/web/20161204130815/http://www.haberdar.org/spatial-frequency-of-an-image-tutorial.htm | url-status = dead }}

* {{cite web | url = http://webvision.med.utah.edu/KallSpatial.html#contrast | title = Webvision: Part IX Psychophysics of Vision. 2 Visual Acuity, Contrast Sensitivity | publisher = University of Utah | first1 = Michael | last1 = Kalloniatis | first2 = Charles | last2 = Luu | year = 2007 | accessdate = 2009-07 | archive-date = 2009-03-01 | archive-url = https://web.archive.org/web/20090301052435/http://webvision.med.utah.edu/KallSpatial.html#contrast | url-status = dead }}