If I have a single flat object held parallel to my stereo camera plane. Given nature of pinhole camera, would the disparity values be same across the image (ideal case) or values shift as we move from center of the image towards either of the edge?
disparity gives you distance between object and optical center. a constant disparity constant means : a sphere see @Kafan answer : a plane Z=cste
(u1,v1) pixel coordinate in image 1 (u2,v2) pixel coordinate in image 2
u2-u1=d=disparity (images are rectified)
b base
f focal length
mx,my pixels/mm in x or y direction
@LBerger: From your post, it seems you have mentioned the disparity value (depth info) is obtained is basically displacement from optical center till the object in view. Is my understanding correct? Basically I need the disparity in terms of perpendicular distance with plane of camera rather than center of camera. So I am using a pixel's cosine of cast angle with the camera's optical axis (obtained using FOV parameters of camera). Is this approach correct?
@LBerger: Sorry, I could not make myself clear in earlier post. I have attached a image to explain better. https://imgur.com/a/48jMI There are two real points (x',y') and (x,y), lying on the same plane which is parallel to camera plane. I understand disparity is inversely proportional to actual distance from camera. Now this actual distance is displacement from the real object point to optical center or perpendicular distance to camera plane? If it is actual distance, then disparity of these two points calculated would not be same, inspite of having constant distance from camera plane (perpendicular distance, will mean disparity of (x',y') (x,y) will be found same). I believe in this case I can use cosine of the horizontal angle cast w.r.t. to camera axis to bring all values to same scale.
@LBerger: I don't think a constant disparity means a sphere. As per literature that I have gone through, it seems disparity is inversely proportional to perpendicular distance from real world point to camera plane. Thus , a constant disparity means a plane held parallely to camera's plane.
Asked: Apr 6 '18
Seen: 678 times
Last updated: Apr 16 '18
