Current implementation doesn't corresponding to this documentation.
The exact meaning of the return value depends on the threading framework used by OpenCV library:
TBB - Unsupported with current 4.1 TBB release. Maybe will be supported in future.
OpenMP - The thread number, within the current team, of the calling thread.
Concurrency - An ID for the virtual processor that the current context is executing on (0
for master thread and unique number for others, but not necessary 1,2,3,...).
GCD - System calling thread's ID. Never returns 0 inside parallel region.
C= - The index of the current parallel task. SEE: setNumThreads, getNumThreads
This function produces same result as cv::warpPolar(src, dst, src.size(), center, maxRadius,
flags+WARP_POLAR_LOG);
Transform the source image using the following transformation (See REF: polar_remaps_reference_image
"Polar remaps reference image d)"): \(\begin{array}{l} dst( \rho , \phi ) = src(x,y) \\ dst.size()
\leftarrow src.size() \end{array}\)
where \(\begin{array}{l} I = (dx,dy) = (x - center.x,y - center.y) \\ \rho = M \cdot
log_e(\texttt{magnitude} (I)) ,\\ \phi = Kangle \cdot \texttt{angle} (I) \\ \end{array}\)
and \(\begin{array}{l} M = src.cols / log_e(maxRadius) \\ Kangle = src.rows / 2\Pi \\ \end{array}\)
The function emulates the human "foveal" vision and can be used for fast scale and rotation-invariant
template matching, for object tracking and so forth.