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Suppose I have an image like this: image

I would like to fit a number of Gaussians to the image. Number of Gaussians is not known a priori.

This question is generally asked tool/software based (like how can i found by using ...)

So, my question is which way is a good solution to find peaks in an image like this and fit ellipses.

What is the name/solution of this problem in the literature?

bivariate Gaussian fitting/ellipse fitting/mode seeking (mean shift)/ multivariate kde/mixture of Gaussians ...?

My ultimate goal is to find point sources in astronomical images and i am aware of CLEAN algorithm and sextractor tool.

Note: Answers that describing algorithm in brief would be more helpful.

orkan
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  • You may be interested in something like this: http://docs.opencv.org/2.4/doc/tutorials/imgproc/imgtrans/hough_circle/hough_circle.html as explained also here: http://stackoverflow.com/questions/9860667/writing-robust-color-and-size-invariant-circle-detection-with-opencv-based-on – Bob__ Jan 09 '16 at 10:51
  • i think circle detection is a different problem. My shapes are ellipses. – orkan Jan 09 '16 at 11:11
  • So you may need this: http://docs.opencv.org/2.4/doc/tutorials/imgproc/shapedescriptors/bounding_rotated_ellipses/bounding_rotated_ellipses.html and consider this: http://stackoverflow.com/questions/13760110/using-opencv-fitellipse-for-circle-fitting/17820398#17820398 – Bob__ Jan 09 '16 at 11:21
  • it uses a global threshold value to first convert image to binary and then find contours and fit ellipses this is not what i am talking about. i think you should review your links before posting them – orkan Jan 09 '16 at 11:47
  • Sorry, I thought that for "solution to find peaks in an image like this and fit ellipses" you could consider a library that is able to "find the different features of contours, like area, perimeter, centroid, bounding box etc" as explained here: http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_imgproc/py_contours/py_contour_features/py_contour_features.html but you were surely asking for something else. In the wrong site, BTW. – Bob__ Jan 09 '16 at 12:25
  • i am asking for in the right place but i think you are working in opencv marketing unit. Because they are all unrelated to the topic. – orkan Jan 09 '16 at 13:21

1 Answers1

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Sextractor is clearly the reference here. One alternative is photutils, an Astropy affiliated project:

It is a young package, so it should be used with some care, but it can do a good job (it depends also on your data). There are also some software that use priors (position, shapes), for example TPHOT (1505.02516).

saimn
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  • I fixed the source detection link but could not find an updated link for Gaussian PSF – uhoh Nov 17 '22 at 10:03
  • great! I'm looking at images of spots on a phosphor screen from electron diffraction rather than stars, but photutils' source detection is very close to what I need and it's easy to find and modify. – uhoh Nov 18 '22 at 14:13