Comments on: Jähne test pattern – take 3 https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/?s_tid=feedtopost Retired from MathWorks in 2024 after 30 years of service. Can now be found at MATLAB Central, https://hornjourney.com, and https://matrixvalues.com. MathWorks career included image processing, toolbox development, MATLAB development and design, development team management, MATLAB design standards, Steve on Image Processing blog (https://blogs.mathworks.com/steve). Co-author of Digital Image Processing Using MATLAB (https://www.imageprocessingplace.com/DIPUM-3E/dipum3e_main_page.htm). French horn enthusiast, member of Concord Orchestra and Melrose Symphony, member of the board of Cormont Music and the Kendall Betts Horn Camp. Tue, 29 Oct 2019 20:47:37 +0000 hourly 1 https://wordpress.org/?v=6.2.2 By: Sepide https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-28649 Mon, 10 Apr 2017 15:22:56 +0000 https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-28649 How can I create a Fresnel zone plate with finite number of rings?

]]>
By: Xin https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24401 Sat, 13 Aug 2011 08:58:00 +0000 https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24401 The pattern is also referred to as Fresnel zone plate in the holography field. A feature of this pattern is that the frequency is increasing or decreasing with the space. As for the pattern, an accurate Fourier transform result is difficult to obtain.

]]>
By: Steve https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24357 Fri, 22 Jul 2011 19:06:44 +0000 https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24357 Dave—Yes, MTF measurement using this pattern is discussion in a section called “Test Pattern for OTF Measurements.” You can find scanned pages of this section of the book’s second edition at Google Books. Search for “MTF”.

]]>
By: Dave S. https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24356 Thu, 21 Jul 2011 20:58:38 +0000 https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24356 Thanks Steve, one definitely can’t stare at this pattern too long :)

It looks like an MTF could be calculated using a radial slice or average — is there anything in the Jahne book that leads in this direction?

]]>
By: Mo https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24353 Wed, 20 Jul 2011 21:03:20 +0000 https://blogs.mathworks.com/steve/2011/07/19/jahne-test-pattern-take-3/#comment-24353 Something really weird – if I quickly scroll up and down, the image (a) seems to be modulated by a sinusoidal manifold that runs along the direction of motion and, better (b) seems to have smaller ‘ripples’, specially at the cardinal points.

The original scan doesn’t seem to have much of the first and definitely not the second – in fact if you look from different angles, you can see the ‘cardinal ripples’ in the final image, and lighter ripples symmetrically organized.

What’s going on?! (If it’s just me, I’m off to get an MR)

]]>