4. Sub Function Descriptions: CIRNangles2R

• CIRNangles2R

  • Description:

  This function creates a Rotation matrix R that takes real world coordinates and converts them to camera coordinates (Not UV, but rather Xc,Yc, and Zc). The inputs are the pose angles as defined by CIRN, referenced and explained below. The camera axes are defined as Zc positive out of the lens, positive Yc pointing towards the top of the image plane, and positive Xc pointing from right to left if looking from behind the camera. The R is created from a ZXZ rotation of these angles in the order of azimuth, tilt, and swing. Diagrams of coordinate systems can be found in Section 5. All values should be in radians.

  If angles are defined another way (omega,kappa,phi, etc) this function will have to be replaced or altered for a new R definition. Note, the R should be the same between angle definitions, it is the order of rotations and signage to achieve this R that differs.

  • Input:

  Variable	Size	Description
  azimuth	[1x1]	The horizontal direction the camera is pointing and positive CW from World Z Axis.
  tilt	[1x1]	The up/down tilt of the camera. 0 is the camera looking nadir, +90 is the camera looking at the horizon right side up. 180 is looking up at the sky and so on.
  swing	[1x1]	The side to side tilt of the camera. 0 degrees is a horizontal flat camera. Looking from behind the camera, CCW rotation of the camera would provide a positive swing.

  • Output:

  Variable	Size	Description
  R	[3x3]	Rotation matrix to transform World to Camera Coordinates

  • Required Core Sub-Functions:

    None.