Hi Everyone
I'm quite new to to image processing world and trying to find a way to count a lot of bubbles in a series of videos (see yhe link below). The purpose of this email is to seek some help and see see if it is possible to isolate the bubbles in the sample frame or no. With my experience and level of expertise, it is not. Thanks for your help, https://www.dropbox.com/s/6s3426by30xivkl/Movie%201.mov?dl=0 -- ------------------------------------------------- Mahdi Razaz ([hidden email]<mailto:[hidden email]>) Postdoc Fellow Dept. of Marine Sciences, University of Georgia 247 Marine Sciences Building, Athens GA 30602 voice: 706 542-2405 Website: http://www.marsci.uga.edu/directory/mahdi-razaz -- ImageJ mailing list: http://imagej.nih.gov/ij/list.html 1-0904090252B.JPEG (445K) Download Attachment |
Hi Mahdi,
Assuming that the bubbles you want to count are the dark objects quickly moving up near 1/3 from the left: In theory it should work like the following: First you need to import the movie as an ImageStack. If ImageJ can't open the movie, use a tool like ffmpeg to convert it into single images and then get those with Import>Image Sequence. If the amount of data is too large, crop it to the relevant area. It seems that the background does not change much, so an operation like Image>Stacks>Z project should give you the background. Best use 'Median'. If you have black bubbles, 'Max' would be better, but the white objects floating around would disturb it. Then use the Image Calculator to calculate the z-projected image minus the original stack (subtract; since the original is darker, it has to be the second argument). Finally, use a plugin like TrackMate to track the bubbles. The first problem with your image is that the dark bubbles are invisible in front of the dark objects in the background, so tracking the bubbles will be very difficult or impossible. You would need a uniform white object behind the track of the rising bubbles (e.g. white sheet; avoid shadows of the bubbles on it). Another problem is that the dark bubbles appear not well-defined, some of them are very blurry and it is not clear whether these objects are single bubbles or whatever. As a rule of thumb, if it is difficult to decide for a human what is a valid object and what isn't (or how many valid objects a blob contains), there is almost no chance to get it done by image processing. So, with the current movie it looks rather hopeless to me. Michael ________________________________________________________________ On 25.10.18 17:41, Mahdi Razaz wrote: > Hi Everyone > > I'm quite new to to image processing world and trying to find a way to count a lot of bubbles in a series of videos (see yhe link below). > > The purpose of this email is to seek some help and see see if it is possible to isolate the bubbles in the sample frame or no. With my experience and level of expertise, it is not. > > Thanks for your help, > > https://www.dropbox.com/s/6s3426by30xivkl/Movie%201.mov?dl=0 -- ImageJ mailing list: http://imagej.nih.gov/ij/list.html |
Michael's solution for background subtraction looks good, but perhaps Mahdi
should explain the physical situation. Does he only have these videos, or can he intervene eg to place a white card behind the upper part of the stream ? But he will still have varying bubble size, clumping, bubbles behind bubbles etc. If these are gas bubbles, measuring their average size and simply collecting the gas would give a good estimation of their number :-) Alan -- ______________________________________________ Dr Alan Hewat, NeutronOptics, Grenoble, FRANCE <[hidden email]> +33.476.98.41.68 http://www.NeutronOptics.com/hewat ______________________________________________ -- ImageJ mailing list: http://imagej.nih.gov/ij/list.html |
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