public int BuildOctaves(ImageMap source, double scale,
int levelsPerOctave, double octaveSigma, int minSize)
{
octaves = new ArrayList();
DScaleSpace downSpace = null;
ImageMap prev = source;
while (prev != null && prev.XDim >= minSize && prev.YDim >= minSize)
{
DScaleSpace dsp = new DScaleSpace();
dsp.Verbose = verbose;
if (verbose)
{
Console.WriteLine("Building octave, ({0}, {1})", prev.XDim, prev.YDim);
}
dsp.BuildGaussianMaps(prev, scale, levelsPerOctave, octaveSigma);
dsp.BuildDiffMaps();
octaves.Add(dsp);
prev = dsp.LastGaussianMap.ScaleHalf();
if (downSpace != null)
{
downSpace.Up = dsp;
}
dsp.Down = downSpace;
downSpace = dsp;
scale *= 2.0;
}
return(octaves.Count);
}
public int DetectFeaturesDownscaled(ImageMap img, int bothDimHi,
double startScale)
{
globalKeypoints = globalNaturalKeypoints = null;
if (printWarning)
{
Console.Error.WriteLine("");
Console.Error.WriteLine("===============================================================================");
Console.Error.WriteLine("The use of this software is restricted by certain conditions.");
Console.Error.WriteLine("See the \"LICENSE\" file distributed with the program for details.");
Console.Error.WriteLine("");
Console.Error.WriteLine("The University of British Columbia has applied for a patent on the SIFT");
Console.Error.WriteLine("algorithm in the United States. Commercial applications of this software may");
Console.Error.WriteLine("require a license from the University of British Columbia.");
Console.Error.WriteLine("===============================================================================");
Console.Error.WriteLine("");
}
if (bothDimHi < 0)
{
img = img.ScaleDouble();
startScale *= 0.5;
}
else if (bothDimHi > 0)
{
while (img.XDim > bothDimHi || img.YDim > bothDimHi)
{
img = img.ScaleHalf(); //pass
startScale *= 2.0;
}
}
if (preprocSigma > 0.0)
{
GaussianConvolution gaussianPre =
new GaussianConvolution(preprocSigma);
img = gaussianPre.Convolve(img);
}
pyr = new OctavePyramid();
pyr.Verbose = verbose;
pyr.BuildOctaves(img, startScale, scaleSpaceLevels,
octaveSigma, minimumRequiredPixelsize);
globalKeypoints = new ArrayList();
for (int on = 0; on < pyr.Count; ++on)
{
DScaleSpace dsp = pyr[on];
ArrayList peaks = dsp.FindPeaks(dogThresh);
if (verbose)
{
Console.WriteLine("Octave {0} has {1} raw peaks",
on, peaks.Count);
}
int oldCount = peaks.Count;
ArrayList peaksFilt = dsp.FilterAndLocalizePeaks(peaks,
maximumEdgeRatio, dValueLowThresh, scaleAdjustThresh,
relocationMaximum);
if (verbose)
{
Console.WriteLine(" filtered: {0} remaining from {1}, thats % {2:N2}",
peaksFilt.Count, oldCount, (100.0 * peaksFilt.Count) / oldCount);
Console.WriteLine("generating keypoints from peaks");
}
dsp.GenerateMagnitudeAndDirectionMaps();
ArrayList keypoints = dsp.GenerateKeypoints(peaksFilt,
scaleSpaceLevels, octaveSigma);
dsp.ClearMagnitudeAndDirectionMaps();
globalKeypoints.AddRange(keypoints);
}
return(globalKeypoints.Count);
}
