[Insight-users] angles orientation in Rigid2DTransform subclasses

[Tom Vercauteren]

Hello everybody,

It seems to me that the angles in Rigid2DTransform subclasses are
given with clockwise orientation instead of the usual
counter-clockwise one.
The following lines can be found in itkEuler2DTransform.txx,
itkCenteredRigid2DTransform.txx and itkSimilarity2DTransform.txx.
/////////////
const double ca = cos( angle );
const double sa = sin( angle );

this->m_RotationMatrix[0][0]= ca;    this->m_RotationMatrix[0][1]=-sa;
this->m_RotationMatrix[1][0]= sa;     this->m_RotationMatrix[1][1]= ca;
////////////////


In itkAffineTransform.txx (used in
Examples/Filtering/ResampleImageFilter3.cxx) the function Rotate2D is
using the usual orientation:
//////////////////////
trans[0][0] =  cos(angle);
trans[0][1] =  sin(angle);
trans[1][0] = -sin(angle);
trans[1][1] =  cos(angle);
/////////////////////

Is there a reason for this incoherence?

Best regards,

Tom Vercauteren