Image Sequence labelling problem
in [Matlab]
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From: Krithika Mohan on 16 Jun 2010 18:07 Hi, I have the following problem, I have a sequence of images of moving cells, some of the cells try to merge and split in subsequent frames. In order to track their movement I tried to label the cells in each of the frames and tried to track their centroid positions. Now the problem is my labelling for each cell varies from frame to frame, due to which my tracks are inaccurate. How should I tackle this problem, what should I do so that I assign unique ID's to each of the cells and at the same time monitor the process of cell splitting and merging of some of the cells.
From: ImageAnalyst on 16 Jun 2010 18:22 MATLAB labels from top down then left to right. If your objects move, it may not have the same label in each image. In that case, you need to let MATLAB first label the image, and then figure out yourself which label corresponds to the label of the prior frame. If the objects are not moving too fast, and don't overlap each other then I'd probably try to keep track of the centroids. You can then develop an N by 1 matrix where the element index is the label MATLAB assigned to the object, and the value of the matrix at that element is the new label that you want to assign to it (which is the label that that object has in prior frames). You can use intlut() on your labeled image to create a labeled image with the labels that you want. It's really not too hard at all. Just have a for loop where you look at every object in the current frame. In there have a for loop where you compare that object to each of the objects from the prior frame. After that inner loop, keep track of which prior object matched the best. Now you have your N by 1 matrix, so just call intlut on your current labeled matrix to remap it to your prior labels, then do your measurements (regionprops probably) with your new labels. Not too bad. You have to put in some sanity checks such as throwing out objects if they don't match close enough to any of the prior objects, or you can keep them and give them a new label - that sort of thing. The only trouble you might run into is if your objects move so much from one frame to the next that you can't really tell where one object went to, or if some objects come into view or leave the view (in which case you'd have to inspect more than just the centroid to find the proper objects), or if the objects change shape and position and count. If the image changes too much it could be impossible (for example you're tracking cars on a New York City street but you're snapping photos only every 5 minutes).
From: ImageAnalyst on 16 Jun 2010 18:23 See my answer on your duplicate posting.
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