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| bio | website | |
|---|---|---|
| location | Munich, Germany | |
| age | 35 | |
| visits | member for | 1 year, 4 months |
| seen | 10 hours ago | |
| stats | profile views | 467 |
I work at a small mechanical engineering company, where I develop software and image processing algorithms for camera-based inspection machines.
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May 12 |
comment |
Does LinearModelFit perform an ordinary linear regression (least squares)? @Rojo: Thanks! That's exactly what I wanted to know. |
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May 9 |
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How can I return the color at a coordinate in an image? This gives the wrong values! The values in p are coordinates, so they are 0-based, start at the bottom-left corner and are stored in x/y order. Extract expects array indices, which are 1-based, start at the top-left corner and are in row/column (i.e. y/x) order. So the values you get are transposed, upside down and shifted by one pixel. |
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May 7 |
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Why is arithmetic faster for inexact arithmetic? At least for inexact arithmetic, I'm pretty sure Mathematica never looks for the roots of a polynomial (because that's not numerically stable). It probably uses an iterative method like Jacobi's. |
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May 7 |
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Does LinearModelFit perform an ordinary linear regression (least squares)? Is there a reason why you use RandomReal[NormalDistribution[] instead of RandomVariate[NormalDistribution[], ? Can RandomReal work with any distribution? If yes, what's the point of RandomVariate anyway? |
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Apr 30 |
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How to compare graphical objects? What data do you have? A list of polygons? An image? A set of points? With or without outliers? Do you know point correspondences between the compared objects? Maybe FindGeometricTransform could help? |
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Apr 29 |
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How to compare graphical objects? Sort the lengths of the sides and compare them? |
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Apr 24 |
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looking for a generalised Hough Transform function or a least a function to locate circles @s.s.o: A hough transform can find circles even if they're not connected components (and circles detected e.g. using EdgeDetect are often not connected). But I think MMA has no built in generalized or circle hough transform. It would be relatively straightforward (but slow) to simulate it by convolving the image with circles with different radii. |
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Apr 22 |
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Get Coordinates in Image Processing +1. Instead of Dilation, you can use the ComponentMeasurements overload that takes a label matrix instead of an image: ComponentMeasurements[ImageData[Binarize[i]], "Centroid"]. That way, you'll always get a single component, because the label matrix only contains 0 and 1. |
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Apr 19 |
answered | Rotate a grid, made up of lines, so that it aligns with the xy axes |
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Apr 19 |
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Rotate a grid, made up of lines, so that it aligns with the xy axes +1. slope could be made shorter: slope[s_, e_] := ArcTan @@ (e - s) |
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Apr 19 |
awarded | Nice Answer |
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Apr 18 |
answered | How to detect crosses and circles in 60x60 raster images? |
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Apr 18 |
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How to detect crosses and circles in 60x60 raster images? In general, ImageCorrelate and ComponentMeasurements might be worth a try. |
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Apr 18 |
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How to detect crosses and circles in 60x60 raster images? Can you add a few sample images, so potential answerers can test their answers? |
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Apr 17 |
awarded | Nice Answer |
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Apr 17 |
answered | How to find the center of a circular pattern? |
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Apr 17 |
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How to find the center of a circular pattern? Is the brightness always symmetrically distributed (as in the sample image you showed)? Then you could just calculate the center of mass of the (possibly thresholded or binarized) image. That's an O(N) operation instead of O(N Log(N)) for the FFT version. |
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Apr 16 |
awarded | Fanatic |
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Apr 6 |
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Cover a rectangle with size constrained rectangular regions And also here: stackoverflow.com/questions/15837871/… |
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Apr 6 |
revised |
Cover a rectangle with size constrained rectangular regions added 386 characters in body |
