// (Lowe03, p10, "We assume that the original image has a blur of at
// least \sigma = 0.5 ...")
// So, do one initial image smoothing pass.
if (preprocSigma > 0.0) {
GaussianConvolution gaussianPre = new GaussianConvolution(preprocSigma);
img = gaussianPre.convolve(img);
}
pyr = new OctavePyramid();
pyr.setVerbose(verbose);
pyr.buildOctaves(img, startScale, scaleSpaceLevels, octaveSigma, minimumRequiredPixelsize);