Timeline for Detecting overlapping blobs in image?
Current License: CC BY-SA 3.0
18 events
| when toggle format | what | by | license | comment | |
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| Oct 10, 2017 at 17:30 | vote | accept | Jonathan | ||
| Oct 9, 2017 at 16:39 | answer | added | Kazuhito | timeline score: 2 | |
| Oct 9, 2017 at 7:03 | comment | added | Jonathan | @Vince If you could also post your partial solution of using distance calculation with local maxima, that'd be really nice. | |
| Oct 8, 2017 at 14:14 | vote | accept | Jonathan | ||
| Oct 10, 2017 at 17:30 | |||||
| Oct 8, 2017 at 4:47 | comment | added | xunilk | You need an algorithm that detect "V shapes" (2 for each overlapping and equivalent a "neck ") in each group of blobs (slope abruptly changes direction in that singular points). In above example, there are 12 "V" shapes, so number of individual overlapped blobs is 12 "V" shapes /2 +1 = 7. For an isolated blob: 0 "V" shapes/2 + 1 = 1. For group of 3 overlapped blobs: 4 "V" shapes/2+ 1 = 3 and so on. You need to analyze mathematically for that your array of arrays (contours). | |
| Oct 8, 2017 at 4:35 | answer | added | xunilk | timeline score: 3 | |
| Oct 7, 2017 at 20:48 | comment | added | Jonathan | @PolyGeo Now I understand. Yes, I'm able to detect all isolated shapes with 100% accuracy. I use the findcountour function in python, and given the color contrast, it does a great job of detecting every isolated raster blob and returns array of arrays(contours). | |
| Oct 7, 2017 at 20:29 | comment | added | PolyGeo♦ | I am not asking if you can create those raster blobs. I am asking how far you have progressed in recognizing isolated raster blobs as vector circles before trying to recognize overlapping vector circles in raster blobs that touch. | |
| Oct 7, 2017 at 20:13 | comment | added | Jonathan | @Vince I can read the image as a matrix as it is originally in tif format. Then, I can convert that matrix to a vector in matlab, if that helps. I'm just not sure how to proceed from there. | |
| Oct 7, 2017 at 19:30 | history | edited | Jonathan | CC BY-SA 3.0 |
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| Oct 7, 2017 at 19:26 | comment | added | Jonathan | Hello Vince, I understand the difference between vector(composed of lines,paths) and raster(composed of pixels), but I don't quite understand how you deduced that this image requires vector, raster, and an NP complete problem. I'm more of software engineering background. So, if you could explain further what you meant, for knowledge sake, that'd be very helpful. How would I take out the raster to vector component? And as you suggested, I'm only after how to detect the tightly overlapping figures. I've edited the question to reflect that. | |
| Oct 7, 2017 at 19:21 | comment | added | Jonathan | @PolyGeo I'm not sure I understand. Can you please elaborate? What I've understood is the following. You're asking if I can create those blobs? No, I cannot create those blobs. I receive those images as such. | |
| Oct 7, 2017 at 11:13 | comment | added | Vince | I'd think that a distance calculation with local maxima would get you 18-19 of the 20, but the tightly overlapped v. ellipse and edge case calculations would take some time to evaluate. The fact that this question encompasses both vector and raster and an NP-complete problem (computer vision) makes it extremely broad for our Focused Q&A format. If you can take out the raster to vector component, and the simple circles which are easily detected, and focus on the tightly overlapping figure problem in vector space, you'd likely get a better answer. | |
| Oct 7, 2017 at 11:05 | review | Close votes | |||
| Oct 7, 2017 at 12:45 | |||||
| Oct 7, 2017 at 9:13 | comment | added | PolyGeo♦ | Have you been able to create the circles (from your image) that you wish to test for overlap yet? If not, then I think the Q&As that you have looked at are only relevant to your next step. I think your question here needs to start with "how to create circles from non-overlapping blobs?", then "how to create circles from overlapping blobs?" | |
| Oct 7, 2017 at 9:08 | history | edited | PolyGeo♦ | CC BY-SA 3.0 |
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| Oct 7, 2017 at 8:54 | review | First posts | |||
| Oct 7, 2017 at 9:18 | |||||
| Oct 7, 2017 at 8:54 | history | asked | Jonathan | CC BY-SA 3.0 |