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movement
Anonymous
8 months

Buy the Pololu Servo Controller from Trossen Robotics
hello, i have been following the movement of an object using roborealm's movement module. given that the movement percent of the module are in terms of pixels, can i translate this data into another unit, such as maybe velocity of the object? thanks.
Steven Gentner from United States  [2169 posts] 8 months
Yes, that is possible to translate into a velocity (say km per hour) but you will need to know more about the scene you are imaging to know how far an object is traveling based on how far the object moves within the image. This can be empirically determined by simplying measuring the distance the object moves and how many pixels it moved. The ratio of the two gives you a forumla to convert pixels to distance. BUT if the object moves towards or away from the camera then this fails. Namely, objects closer to the camera will move more pixels for the same distance traveled by an object away from the camera. This is commonly seen by looking out the side window of a car when traveling ... the pavement is moving very fast but the mountains in the distance are not.

So if you can constrain your environment then this is possible, if not you will have to look into a 3d sensor in order to get the distance from the camera the object is which will allow for an adaptive measurement of overall speed.

STeven.

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