Operators |
invar_fourier_coeff — Normalize the Fourier coefficients.
invar_fourier_coeff is obsolete and is only provided for reasons of backward compatibility.
invar_fourier_coeff( : : RealCoef, ImaginaryCoef, NormPar, InvarType : RealInvar, ImaginaryInvar)
Elimination of affine information from the Fourier coefficients, determination of affine invariants. The Fourier coefficients will be normalized suitably so that all affine correlated contours will be projected to one and the same contour. The following levels of affine mappings are available:
Translations (InvarType = 'transl_invar')
+ Rotations (InvarType = 'congr_invar')
+ Scalings (InvarType = 'simil_invar')
+ Slanting (InvarType = 'affine_invar')
For the input Fourier coefficients (RealCoef, ImaginaryCoef) only odd numbers of parameter values are allowed. The control parameter InvarType indicates up to which level the affine representation shall be normalized. Please note that indicating a certain level implies that the normalizing is executed with regard to all levels below. For most applications a subsequent normalizing of the starting point is recommended!
Real parts of the Fourier coefficients.
Imaginary parts of the Fourier coefficients.
Input of the normalizing coefficients.
Default value: 1
Suggested values: 1, 2
Restriction: NormPar >= 1
Indicates the level of the affine mappings.
Default value: 'affine_invar'
List of values: 'affine_invar' , 'congr_invar' , 'simil_invar' , 'transl_invar'
Real parts of the normalized Fourier coefficients.
Imaginary parts of the normalized Fourier coefficients.
prep_contour_fourier(trow,tcol,"unsigned_area",¶m_scale); fourier_1dim(trow,tcol,param_scale,&frow,&fcol); invar_fourier_coeff(frow,fcol,1,"affine_invar",&invrow,&invcol); abs_invar_fourier_coeff(invrow,invcol,1,2,"az_invar1",&absrow,&abscol);
Foundation
Operators |