fourier_1dim

fourier_1dim_inv ( : : RealCoef, ImaginaryCoef, MaxCoef : Rows, Columns )

One dimensional Fourier synthesis (inverse Fourier transform).

Backtransformation of Fourier coefficients respectively of Fourier descriptors. The number of values to be backtransformed should not exceed the length of the transformed contour.

Parameters

`RealCoef` (input_control)	real-array `->` real
Real parts.

`ImaginaryCoef` (input_control)	real-array `->` real
Imaginary parts.

`MaxCoef` (input_control)	integer `->` integer
Input of the steps for the backtransformation.
Default value: 100
Suggested values: 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 400
Restriction: `MaxCoef >= 1`

`Rows` (output_control)	contour.y-array `->` real
Row coordinates.

`Columns` (output_control)	contour.x-array `->` real
Column coordinates.

Example (Syntax: C++)

get_region_contour(single,&row,&col);
length_of_contour = row.Num();
move_contour_orig(row,col,&trow,&tcol); 
prep_contour_fourier(trow,tcol,"unsigned_area",&param_scale);
fourier_1dim(trow,tcol,param_scale,50,&frow,&fcol);
invar_fourier_coeff(frow,fcol,1,"affine_invar",&invrow,&invcol);
abs_invar_fourier_coeff(invrow,invcol,1,2,"az_invar1",&absrow,&abscol);
fourier_1dim_inv(absrow,abscol,length_of_contour,&fsynrow,&fsyncol);

Parallelization Information

fourier_1dim_inv is reentrant and processed without parallelization.

Possible Predecessors

invar_fourier_coeff, fourier_1dim

Possible Successors

disp_polygon

Module

Foundation