   Vectorizing Problem @ Image Processing
  Hi,I''ll try to make it short, here-#s the question.I got an image and need to recognize objects and convert them to 3d data.I got the object filtered clean out of the image but it''s still pixel-data (imagine a red "something" in an white image). The next step is to vectorize the object and get the VertexPoints of it in 2d. The conversion to 3d coords are no problem.The only problem is that i got no idea how to get the lines that build up the object.i searched google for almost 4 days now and havent found one useful information. would be nice if someone could help me or point me somewhere.thx in advance, mathias pain.ps: sry for my bad english. 
  What algo have you used for finding the red "something"?Try searching for snakes. They can be used for approximating a shape around a blob. ;  I wonder if edge detection would help you. It should, at the very least, turn the ''red object'' into an outline (which you can then try and fit to lines, and thus find points). ;  are you interested just in the outline or every ''edge'' of the object? how complex are those objects?-Mat ;  If you want to find answers learn to ask questions  (Goes in equal amounts for forums as for web searches.)What exactly are you trying to do? Structure from motion? Stereo correspondence? Or do you have range data for the image from some type of grid scan?Why cant you just build a dense mesh? (One vertex per pixel, ie the trivial solution.) ;  ok, we are doing a robot with simple image recognition.so the robot has to recognize object and other things.we got 2 cameras on the robot and so we get 2 pictures per frame.I have to get a 3D model out of the 2 pictures.So I first have to find out whats an object and whats just stuff.I do some pixel tests and FillFloods to delete some wrong pixelclusters. So I finally have a picture with some pixelforms.I do an edge detection and do the outline of them.my problem is that i don't know how to get the right vectors out of an outline. I don't know how the check for corners in the outline since they are not sharp.dense mesh. sounds interesting .. one vertex per pixel.The problem (i think) with this one is that we have to do that process around 2 times per second and want to keep the 3d data small. We got no range data. and building a densemesh out of no depth information sounds very difficult for me.But the idea's not bad, would be nice if you can point me somewhere.(searched and found material but not useful 2 me)thx, mathias pain   [edited by - stryx on February 15, 2004 4:54:37 AM];  Erk. That''s really pretty hard.If you had some reference points on your object, you might be able to do it. If you could attach a small sticker or something - a different colour to the rest of the object - then you could find it in each camera image. Once you''ve got that, and you know the distance between the two cameras, it becomes a problem of geometry to find the distance of that point from the robot.However, doing that for all the points? I''m not sure it''s even possible... you need to be able to identify a given point in both images, I think is the key problem. ;  I have downloaded a free vectorizer .exe that has been developped in a french university (just happened like this I searched www). It worked well, it enabled me for instance to take a screenshot of a 3D model (in a model editor) and convert it to SVG, that I include in my html docs. It worked very well specially as I only used flat shading. Once you set the right parameters you nearly get the original mesh structure, of course only the visible part, which shows the algorithm works well.Hmm I don''t have it on this PC but Google seek : vectorizer, France or french and you should find the pointer again. Sadly as far as I remember the .exe and the code are not freely available anymore. One the researcher seems to have a patent now and started a buisiness.One question though 2D -> 3D. How do you guess missing 3rd dimension info if you don''t have a z-buffer in the original image. Using multiple viewpoints of the object ?Well if you are interested I can probably help you find more info about it. Just reply here.;  Since we get 2 pictures of two different cameras wich are set up by a constant angle we search for patterns in an image and search for it in the second image.so we got the delta of the x-positions in the images.the cameras are set up so the lines of view cross somewhere.Just imagin 2 points wich are the lower points of an X.We fit the delta into the X so we get the "height" where we fit, and thats the distance.The idea of getting small stickers on the object sounds nice.. well. at least for testing this would help.thx for all your help until now.further help would be nice too.thx, mathias pain;  so your problem is finding corners?try:-harris corner detector-feature detection via ''phase congruency''-using canny edge detector direction information to find edges-feature dection via ''hough'' transformsalso look into morphological operations. 