Go to Post Stupid programmer question: where does the tread go? - Joel J [more]
Home
Go Back   Chief Delphi > Technical > Programming
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 08-02-2016, 19:25
RoboKnight RoboKnight is offline
Registered User
FRC #5496
 
Join Date: Jan 2016
Location: Vacaville
Posts: 3
RoboKnight is an unknown quantity at this point
Microsoft Lifecam Angle

We are trying to use a Microsoft LifeCam HD-3000 on our robot. However, in order to perform some of the functions we want on it, we need to know the angle of camera.

A comment in the 2015 Vision Retro Sample given in the wpilib plugin states that the angle for what we want (HD3000 640x480) is 60 degrees, which we were going to use.

However, I have read the Technical Data Sheet for this camera and have come to some interesting conclusions. The data sheet states that the camera is a 1280x720 camera, and that it has a 68.5 degree diagonal angle(I assumed that the comment on the retro sample was referring to a diagonal angle as well, but it didn't specify). To make the ratio work, I first calculated what the angle would be if horizontal view was cropped and the height remained the same, which would be a 55.97 degree diagonal axis. I then calculated the diagonal angle if they just cropped a 640x480 from the middle of the image, which would come to 37.31 degrees.

I am unsure if I am bad at math (definite possibility) or whether the angle given in the comment was inaccurate, but we need to be sure the angle is correct to code the camera properly. What diagonal angle are you using in your code?
  #2   Spotlight this post!  
Unread 08-02-2016, 19:44
Mark McLeod's Avatar
Mark McLeod Mark McLeod is offline
Just Itinerant
AKA: Hey dad...Father...MARK
FRC #0358 (Robotic Eagles)
Team Role: Engineer
 
Join Date: Mar 2003
Rookie Year: 2002
Location: Hauppauge, Long Island, NY
Posts: 8,906
Mark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond repute
Re: Microsoft Lifecam Angle

It might simply be the difference between a diagonal angle of view vs a horizontal angle of view.
e.g., http://vrguy.blogspot.com/2013/04/co...-view-and.html although this example is only an approximation

See also "Measuring a camera's field of view" in https://en.wikipedia.org/wiki/Angle_of_view
__________________
"Rationality is our distinguishing characteristic - it's what sets us apart from the beasts." - Aristotle

Last edited by Mark McLeod : 08-02-2016 at 19:48.
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 01:29.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi