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how do calibration parameters change on halving the image

asked 2020-01-31 10:08:31 -0500

2ROS0 gravatar image

updated 2020-01-31 10:09:06 -0500


How do the intrinsics and extrinsics change if we half the image i.e.

height_new = height/2 width_new = width/2

In the CameraInfo message, obviously the height and width change but how do you modify K D R and P?

Thank you

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This doesn't answer your question, but image_proc will do all of the operations for you with crop_decimate or resize nodes or nodelets.

Thomas D gravatar image Thomas D  ( 2020-02-01 09:55:32 -0500 )edit

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answered 2020-03-01 23:30:19 -0500

I think this shouldn't necessarily change the extrinsic parameters, since this parameters basically defines a transform between two "rigid" bodies(e.g you use this parameters to transform a LIDAR point to camera frame, all in 3D space). However this should change the intrinsic parameters. If you look at, what parameters are regraded as intrinsic ones; From wiki;

image description

So from here one will expect the change in size of your image should effect principal point(u_0,v_0). Principal point would/should be multiplied by the factor you divide your image.

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Asked: 2020-01-31 10:08:31 -0500

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Last updated: Mar 01 '20