openpiv.pyprocess.find_subpixel_peak_position

static pyprocess.find_subpixel_peak_position(corr, peak_indices, subpixel_method='gaussian')

Find subpixel approximation of the correlation peak.

This function returns a subpixels approximation of the correlation peak by fitting a two dimensional Gaussian curve in a 3x3 square region around the correlation peak.

Parameters :

corr : np.ndarray

the correlation map

peak_indices: two elements tuple :

the row and column indices of the first correlation peak

subpixel_method : string

one of the following methods to estimate subpixel location of the peak: ‘centroid’ [replaces default if correlation map is negative], ‘gaussian’ [default if correlation map is positive], ‘parabolic’

Returns :

subp_peak_position : two elements tuple

the sub-pixel approximation of the correlation peak