#robotics Logs

Aug 30 2019

01:38 AM mrdata: goppo, i dont know? but this is an interesting question
01:42 AM mrdata: let me know if you find out
02:12 AM ib0t: I think it is more because of the opening angle and the pattern of the structured light
02:12 AM ib0t: it projects a pattern to the environment and if you are to close to the camera it is not possible to see the full pattern that is needed to calculate the distance
02:35 AM mrdata: ib0t, that makes sense if the pattern emitter is not the camera lens.. which i sguess is always
02:35 AM mrdata: sure
02:42 AM goppo: ib0t but would attaching a wide angle lens over the IR camera reduce the minimum depth range then?
02:42 AM ib0t: yes for sure but you can not zero it
02:43 AM ib0t: and it will getting more inprecisse because you have more distortion
02:43 AM goppo: actually, would a wide angle lens make it worse since the dots may become even closer together?
02:43 AM ib0t: and lens distortion is a intrinsic parameter you need to calibrate for each camera which is not so easy
02:44 AM goppo: i've just tried putting a wide angle (glass) lens over the IR camera, but i get no depth image at all
02:45 AM goppo: i wonder if it's because the glass lens blocks off the IR speckles or the speckles are just too distorted
02:45 AM goppo: and i've tried calibrating with a checkerboard
02:46 AM goppo: would a zoom lens work better?
02:46 AM ib0t: if the camera itself do the calculation of the depth image then you would need to change the intrinsic parameters in this algorithm and recalibrate it
02:47 AM ib0t: where is the calculation of the depth image done? on your camera or do you do it by yourself?
02:47 AM goppo: ib0t the camera does it
02:47 AM goppo: like kinect does
02:48 AM goppo: (i think?)
02:48 AM ib0t: than you have no chance to change the lens
02:48 AM ib0t: because this has huge effects to the intrinsic parameters
02:48 AM goppo: ib0t does kinect do the calculation of the depth image?
02:48 AM ib0t: which are calibrated and stored on the camera by the manufacturer
02:49 AM ib0t: I think so
02:49 AM goppo: ib0t but there's this lens for kinect: https://nyko.com/products/xbox-360-zoom-for-kinect
02:49 AM goppo: and it appears to work: https://www.youtube.com/watch?v=jy5HFHwdQEc
02:50 AM SpeedEvil is now known as Guest84598
02:54 AM goppo: it doesn't seem to require calibration either
02:55 AM ib0t: it has some additional lenses for all of the lenses of the kinect, perhaps it manipulates the structured light in the coresponding way that it works
02:55 AM ib0t: but I think it decreases the precission
02:56 AM goppo: i guess the lens for the RGB camera is unnecessary, right
02:56 AM goppo: probably just the same lens over the IR projector and the IR camera?
02:57 AM ib0t: not the same, a corresponding
02:57 AM goppo: right
02:57 AM goppo: sounds like a nightmare to hack depth camera to reduce depth range
03:28 AM Maya-sama is now known as hackkitten
07:00 AM mun: anyone know how these arms see objects? they don't seem to have cameras mounted on them https://www.youtube.com/watch?v=1QqQLq5hsN4
07:06 AM mun: or this even https://www.youtube.com/watch?v=qDl459EIlBc
07:12 AM mun: oh nevermind. the camera's mounted on the rig
07:12 AM mun: http://nimbro.net/Picking/
07:45 AM Guest38107 is now known as owl
12:51 PM BitEvil is now known as SpeedEvil
06:12 PM logb0t_ is now known as logb0t