Find real position and size of blob in stereo image

Question

Does anyone have any ideas of how I can find the size of a blob or object in a stereo image? I know that the stereo image outputs the depth information, but I want to know how large or high an detected object is. Say I find a bounding rectangle around a detected object that is positioned further into the room. How can I find the height of that bounding rectangle in a metric like for example centimeters?

Answer 1

1. for a stereo pair you need to find the essential matrix/fundamental matrix of the stereo pair
2. detect the object or points on the object and find their correspondence/match in both images. For both point 1 and 2 refer to stereo tutorials.
3. depth can be obtained from the stereo pair information..however for height at which the object is you have to make the computer understand which is your reference as height = 0 (like the floor) . So if you can make the computer understand the location of the floor then just the difference of the y coordinate between the floor and the object is your height.