Vision sensor questions
Posted: 17 Sep 2015, 13:12
Hello,
I have some questions about the way perspective vision sensors are implemented in VREP.
1) I see there is only one entry in angle of view. Does this mean I cannot have different angles in x and y directions?
2) Is there a fixed focal length? I need a way to translate image patch size to imaged object size.
I noticed the answer to this question:
viewtopic.php?t=441&p=1581
But I don't feel it is clear enough in the sense that it doesn't provide a definitive answer as to what the focal length value of a vision sensor is. The focal length cannot be computed by the angle of view alone and I believe that in your implementation you must have a value for the focal length parameter to calculate the projection.
I understand that I could infer the focal length by placing a surface of known size at a known distance in front of the vision sensor and counting pixels but that would take time and probably produce inaccurate results.
Your help will be much appreciated.
Thanks in advance.
I have some questions about the way perspective vision sensors are implemented in VREP.
1) I see there is only one entry in angle of view. Does this mean I cannot have different angles in x and y directions?
2) Is there a fixed focal length? I need a way to translate image patch size to imaged object size.
I noticed the answer to this question:
viewtopic.php?t=441&p=1581
But I don't feel it is clear enough in the sense that it doesn't provide a definitive answer as to what the focal length value of a vision sensor is. The focal length cannot be computed by the angle of view alone and I believe that in your implementation you must have a value for the focal length parameter to calculate the projection.
I understand that I could infer the focal length by placing a surface of known size at a known distance in front of the vision sensor and counting pixels but that would take time and probably produce inaccurate results.
Your help will be much appreciated.
Thanks in advance.