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surfheight
Surface height reconstruction for FS-SS

Description ```H = surfheight(DR, H0, HC, N, [X0,Y0]) computes the surface height H for FS-SS measurements (Free-Surface Synthetic Schlieren). The input arguments are the displacement field(s) DR, the pattern-surface distance H0, the pattern-camera distance HC (can be set to infinity, H=inf), the refraction index N and the optical center [X0,Y0]. H0, HC and [X0,Y0] are expressed in the same units as R (e.g., mm). If N is not specified, N=1.33 by default (water index). If the center [X0, Y0] is not specified, the center of the field is taken. The center does not need to be inside the field. FS-SS random dot patterns can be generated using makebospattern. Additional parameters can be specified, but only *after* the first 6 parameters described above: H = surfheight(..., 'submean') first substracts the mean displacement along each direction. This is useful if the incidence angle of the camera is not exactly 0. H = surfheight(..., 'remap') applies the remapping procedure, as described in Moisy et al (2009). The resulting height field H is smaller than the input displacement field DR, by an amount of about L*H0/HC, where L is the field size, H0 the pattern-surface distance and HC the pattern-camera distance. By default, surfheight produces a height field such that MEAN(H)=H0. Specify H = surfheight(..., 'nosetzero') if you do not want to apply this constraint - in this case, the point (1,1) of the height field is equal to H0, but MEAN(H) is arbitrary. H = surfheight(..., 'verbose') displays the computation progress. surfheight is based on INTGRAD2.M by J. D'Errico. Example dr = loadvec('*.vc7'); h = surfheight(dr, 10, 2000); showf(h); Reference: Moisy, Rabaud, Salsac, "A Synthetic Schlieren method for the measurement of the topography of a liquid interface", Experiments in Fluids (2009). See http://www.fast.u-psud.fr/~moisy/sgbos/tutorial.php See Also makebospattern, showf, vec2scal, gradientf. Published output in the Help browser showdemo surfheight ```
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