Comments on: Spatial transformations: Terminology and notation http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/ 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 01:51:50 +0000 http://wordpress.org/?v=2.3.1 By: Steve http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-21217 Steve Tue, 04 Nov 2008 16:17:03 +0000 http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-21217 Muhmmad—Thanks for topic suggestion. I don't know anything, however, about matching up pixels from a side view to pixels from a top view. Muhmmad—Thanks for topic suggestion. I don’t know anything, however, about matching up pixels from a side view to pixels from a top view.

]]> By: Muhmmad Hanif http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-21216 Muhmmad Hanif Tue, 04 Nov 2008 16:12:35 +0000 http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-21216 Hi, Intresting to learn online about image processing. This blog realy help in many issues. can you please also post some material about 2 view mapping. like 2 view image of same scene. if we have two views of a partical (suppose, side view and top view) in an image, then how can we associate the pixel in top view of the scene with the pixel of side view...... Thanks, Have a Nice time! Enjoy Hi,
Intresting to learn online about image processing. This blog realy help in many issues. can you please also post some material about 2 view mapping. like 2 view image of same scene.
if we have two views of a partical (suppose, side view and top view) in an image, then how can we associate the pixel in top view of the scene with the pixel of side view……
Thanks,
Have a Nice time!
Enjoy

]]> By: Steve http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-25 Steve Wed, 01 Feb 2006 15:27:41 +0000 http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-25 copi - It's hard for me to say what is "common." I've seen a variety of coordinate system conventions in use in all kinds of sources. I have the impression that coordinate systems with the horizontal coordinate first are somewhat more common in computer graphics contexts. Our choice in the Image Processing Toolbox was strongly influenced by what happens in MATLAB when you say plot(x,y). My best advice is to make sure you know what convention is used by whatever system or source you are using. Secondly, I would regard the relationship between MATLAB's default image coordinate system (pixel centers on an integer grid) and a physical coordinate system as simply another step in the spatial transformation. For example, two Cartesian coordinate systems whose axes are aligned are related by an affine transformation consisting of scale factors and translations. If they aren't aligned, you can throw in a rotation. Later on, I'll talk about how to define and perform spatial transformations on images that do not lie on the default integer grid. copi - It’s hard for me to say what is “common.” I’ve seen a variety of coordinate system conventions in use in all kinds of sources. I have the impression that coordinate systems with the horizontal coordinate first are somewhat more common in computer graphics contexts. Our choice in the Image Processing Toolbox was strongly influenced by what happens in MATLAB when you say plot(x,y). My best advice is to make sure you know what convention is used by whatever system or source you are using.

Secondly, I would regard the relationship between MATLAB’s default image coordinate system (pixel centers on an integer grid) and a physical coordinate system as simply another step in the spatial transformation. For example, two Cartesian coordinate systems whose axes are aligned are related by an affine transformation consisting of scale factors and translations. If they aren’t aligned, you can throw in a rotation.

Later on, I’ll talk about how to define and perform spatial transformations on images that do not lie on the default integer grid.

]]> By: copi http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-24 copi Tue, 31 Jan 2006 23:25:22 +0000 http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-24 Hello, In first place congratulations for your blog, an the interesting topics you are teaching about. Is this choice of axis vey commom? If you are trying to reference an 50ge to ground coordinates the output space axis would not be adecuate for coordinates in any cartographic projection system. And what about the input space? Is (column, row) more commom than (row,column)? Hello,
In first place congratulations for your blog, an the interesting topics you are teaching about.
Is this choice of axis vey commom?

If you are trying to reference an 50ge to ground coordinates
the output space axis would not be adecuate for coordinates
in any cartographic projection system.

And what about the input space?
Is (column, row) more commom than (row,column)?

]]> By: Steve http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-23 Steve Tue, 31 Jan 2006 13:15:27 +0000 http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-23 Philip - Fixed the typo. Thanks! Philip - Fixed the typo. Thanks!

]]> By: philip batchelor http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-21 philip batchelor Tue, 31 Jan 2006 13:09:52 +0000 http://blogs.mathworks.com/steve/2006/01/31/spatial-transformations-terminology-and-notation/#comment-21 Oops, typo on the Output Space? Isn't the (u1,v1) in the picture on the right meant to be (x1,y1)? ;) Oops, typo on the Output Space? Isn’t the (u1,v1) in the picture on the right meant to be (x1,y1)? ;)

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