How can I detect objects and distinguish them from each other?

They can be in different colors, or maybe it's better to distinguish them bye edge detection, or some thing else which I need you help me to use a suitable method. Purpose is to detect objects and find their movement if exist and estimate their direction and velocity. Thank you

Answer 1

[Image Analyst]

Please try out my image segmentation demos and color segmentation demos: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

To do object tracking across different images or video frames, you can use the Computer Vision System Toolbox

[roudabe]

Demos was useful, and I detect objects by their colors. Now I need to found the objects which are moving! and their direction and velocity. You mean I should tracking them? Consider that it is part of my project and should contain minimum computation, and takes least possible time.

[Image Analyst]

There are several tracking projects on the File Exchange that track things like laser spots or color balls. Take a look at those.

[roudabe]

Hi, I used regionprops with properties : PixelList to have a set of region pixels, but now I need the pixel list of region for every frame!!! What should I do in for loop?

xyloObj = VideoReader('vid.avi');

nFrames = xyloObj.NumberOfFrames;
vidHeight = xyloObj.Height;
vidWidth = xyloObj.Width;

mov(1:nFrames) = ...
    struct('cdata', zeros(vidHeight, vidWidth, 3, 'uint8'),...
           'colormap', []);

for k = 1 : nFrames
   mov(k).cdata = read(xyloObj, k);
   s = regionprops(mov(k).cdata,'PixelList');
   region=s.PixelList;
   imshow(mov(k).cdata)
end

[Image Analyst]

Read this: http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

s is structure array, you need to index it, like s(k).PixelList. A single frame might have 2 or 10 different regions so you need an index. But then after you (attempt to) get it, you aren't doing anything with it.