http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/ Steve Eddins manages the Image & Geospatial development team at <a href="http://www.mathworks.com/">The MathWorks</a> and coauthored <a href="http://www.mathworks.com/support/books/book5291.html?category=-1&language=-1">Digital Image Processing Using MATLAB</a>. He writes here about image processing concepts, algorithm implementations, and MATLAB.<br><br><img> Mon, 23 Nov 2009 00:53:01 +0000 http://wordpress.org/?v=2.3.1 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-19924 Steve Thu, 07 Feb 2008 19:06:43 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-19924 Scott—Thanks. That link is already at the bottom of my post. Scott—Thanks. That link is already at the bottom of my post.

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-19922 Scott Rickard Thu, 07 Feb 2008 18:15:53 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-19922 lots of information here: www.costasarrays.org lots of information here:
www.costasarrays.org

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-15193 Steve Sun, 18 Nov 2007 21:55:39 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-15193 Varma—This post contains about everything I know about Costas arrays. I suggest that you follow the link at the end of the post to find some papers and examples. Varma—This post contains about everything I know about Costas arrays. I suggest that you follow the link at the end of the post to find some papers and examples.

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-14982 varma Wed, 14 Nov 2007 08:22:42 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-14982 hai steve, congrats for maintainig a good blog.steve i want few costas sequences for N=8 and 10. could you help me out in this regard hai steve,
congrats for maintainig a good blog.steve i want few costas sequences for N=8 and 10. could you help me out in this regard

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6856 Steve Wed, 11 Jul 2007 13:27:53 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6856 Simon—Thanks for the information. Simon—Thanks for the information.

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6855 Simon M. Wed, 11 Jul 2007 09:23:02 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6855 Hello, Steve. Right now we are using the matlab function poly2mask to intersect different drainage areas/patches with image pixels of a rain radar (e.g. 200x200 pixel, 1km² rastersize). Those patches are available as dxf-polygones, the radar information is represented by greyscale images. Since every patch is covered by only 20-30 radar pixels we would like to calculate the exact amount of rainfall for a patch. Nevertheless we are achieving quite good results with the existing poly2mask method. Hello, Steve.
Right now we are using the matlab function poly2mask to intersect different drainage areas/patches with image pixels of a rain radar (e.g. 200×200 pixel, 1km² rastersize).
Those patches are available as dxf-polygones, the radar information is represented by greyscale images.
Since every patch is covered by only 20-30 radar pixels we would like to calculate the exact amount of rainfall for a patch. Nevertheless we are achieving quite good results with the existing poly2mask method.

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6834 Steve Wed, 04 Jul 2007 03:24:08 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6834 Simon—This post and my February 6th post are about a possible method for computing partial pixel coverage. I asked whether anyone was interested. We would like to hear about your use case. Can you describe the scenario in which you'd like to be able to compute this information? What kind of data, where did it come from, how will partial pixel coverage be used? What trouble does it cause if this algorithm is not available? Simon—This post and my February 6th post are about a possible method for computing partial pixel coverage. I asked whether anyone was interested. We would like to hear about your use case. Can you describe the scenario in which you’d like to be able to compute this information? What kind of data, where did it come from, how will partial pixel coverage be used? What trouble does it cause if this algorithm is not available?

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6824 Simon M. Tue, 03 Jul 2007 14:31:35 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6824 Hello, Steve. I'm looking for an easy way to calculate for a given polygon (type uint8 or double) for each pixel not only if it lies in the polygon, but also the coverage, e.g. something like 0.65 of a pixel is covered by the polygon. Do you know any matlab algorithms, which might help me. Thanks in Advance, Simon Hello, Steve. I’m looking for an easy way to calculate for a given polygon (type uint8 or double) for each pixel not only if it lies in the polygon, but also the coverage, e.g. something like 0.65 of a pixel is covered by the polygon.
Do you know any matlab algorithms, which might help me.
Thanks in Advance,
Simon

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6629 Steve Thu, 29 Mar 2007 16:22:02 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6629 A - I posed your question to graphics developer Mike, who first told me about Costas arrays. He pointed out that the success of an antialiasing method depends on properties of human visual perception, and so mathematical measures of optimality tend to be not very helpful. In his experience, "sampling patterns have often been chosen in pretty ad hoc ways with little concern for the underlying math." He suggests looking through <a href="http://commsci.usc.edu/faculty/golomb.html" rel="nofollow">Solomon Golomb's papers</a> for information about the mathematical properties of Costas arrays. A - I posed your question to graphics developer Mike, who first told me about Costas arrays. He pointed out that the success of an antialiasing method depends on properties of human visual perception, and so mathematical measures of optimality tend to be not very helpful. In his experience, “sampling patterns have often been chosen in pretty ad hoc ways with little concern for the underlying math.” He suggests looking through Solomon Golomb’s papers for information about the mathematical properties of Costas arrays.

]]> http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6628 A Brook Thu, 29 Mar 2007 15:11:13 +0000 http://blogs.mathworks.com/steve/2007/02/15/costas-arrays/#comment-6628 Are Costas arrays optimal for this task (antialiasing) in any sense? Is there any literature on the issue? Thanks. Are Costas arrays optimal for this task (antialiasing) in any sense? Is there any literature on the issue? Thanks.

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