static List <ZeroCrossing> FindZeroCrossings(double[] src, int numPoints)
{
if (src == null)
{
throw new ArgumentNullException(nameof(src));
}
if (numPoints < 3)
{
throw new ArgumentOutOfRangeException(nameof(numPoints));
}
List <ZeroCrossing> zeroCrossings = new List <ZeroCrossing>();
double[] modmax = new double[numPoints];
WaveletUtil.ModulusMaxima(src, ref modmax, numPoints);
for (int i = 0; i < numPoints - 1; i++)
{
if ((src[i] < 0.0 && src[i + 1] > 0.0) ||
(src[i] > 0.0 && src[i + 1] < 0.0) || src[i] == 0.0)
{
ZeroCrossing zc = new ZeroCrossing
{
Position = i,
LeftMag = FindLeftExtremum(modmax, numPoints, i),
RightMag = FindRightExtremum(modmax, numPoints, i)
};
zc.Position = i;
zeroCrossings.Add(zc);
}
if (src[i] == 0.0)
{
i++;
}
}
return(zeroCrossings);
}
public int FindNotch(Chain chain, int tipPosition)
{
if (chain == null)
{
throw new ArgumentNullException(nameof(chain));
}
if (tipPosition < 0 || tipPosition > chain.Length)
{
throw new ArgumentOutOfRangeException(nameof(tipPosition));
}
// TODO
//if (_userSetNotch)
// throw new Exception("findNotch() [User selected notch in use]");
// We're only going to be looking on the trailing edge
// of the fin for the most significant notch, so we'll
// build a source vector from that area
int numTrailingEdgePts = chain.Length - tipPosition - 1 - 5;
double[] src = new double[numTrailingEdgePts];
//***1.95 - JHS
// The following original code copies the ABSOLUTE Chain angles into source.
// These are probably in the range -180 .. 180. Is this causing problems with
// angles that cross quadrants between +180 and -180 thus producing a LARGE
// positive change in angle rather than a small negative one. Should the
// angles all be SHIFTED by +180 so the range is 0..360? NO, this does not
// work. However, converting ONLY the negative angles (-91..-180) to positive
// by adding 360 to them DOES WORK. This way there is a continuous change in
// positive outline orientation throughout all leftward extending notches
// except narrow ones opening up and forward. In effect, we have removed potential
// discontinuities from the chain signal being sent into the wavelet code.
//memcpy(src, &((*_chain)[_tipPos + 1]), numTrailingEdgePts * sizeof(double));
Array.Copy(chain.Data, tipPosition + 1, src, 0, numTrailingEdgePts);
//***1.95 - code to convert negative angles
for (int di = 0; di < numTrailingEdgePts; di++)
{
if (src[di] < -90)
{
src[di] += 360.0; // force negative angles to be positive
}
//printf ("%5.2f\n",src[di]);
}
// Now set up the variables needed to perform a wavelet
// transform on the chain
double[,] continuousResult = new double[TransformLevels + 1, MathHelper.NextPowerOfTwo(numTrailingEdgePts)];
// Now perform the transformation
WIRWavelet.WL_FrwtVector(
src,
ref continuousResult,
numTrailingEdgePts,
TransformLevels,
WaveletUtil.MZLowPassFilter,
WaveletUtil.MZHighPassFilter);
int i;
for (i = 1; i <= TransformLevels; i++)
{
for (int j = 0; j < numTrailingEdgePts; j++)
{
continuousResult[i, j] *= WaveletUtil.NormalizationCoeff(i);
}
}
double[,] modMax = new double[TransformLevels, numTrailingEdgePts];
// ..and find its local minima and maxima
for (i = 0; i < TransformLevels; i++)
{
double[] temp = new double[numTrailingEdgePts];
double[] continousExtract = WaveletUtil.Extract1DArray(continuousResult, i + 1, numTrailingEdgePts);
WaveletUtil.ModulusMaxima(continousExtract, ref temp, numTrailingEdgePts);
WaveletUtil.Patch1DArray(temp, ref modMax, i, numTrailingEdgePts);
}
int level = TransformLevels / 2;
if (level < 1)
{
level = 1;
}
// First, we'll find some local minima at an intermediate level
// to track.
int notchPosition = 0;
List <int> mins = new List <int>();
while (level > 0)
{
for (i = 0; i < numTrailingEdgePts; i++)
{
if (modMax[level, i] < 0.0)
{
mins.Add(i);
}
}
if (mins.Count <= 0)
{
level--;
continue;
}
if (mins.Count == 1)
{
notchPosition = 1;
if (0 == notchPosition)
{
notchPosition = chain.Length - tipPosition - 1;
}
break;
}
// yes, bad code
break;
}
if (level == 0)
{
// Well, this really shouldn't happen: we've looked through
// all the fine transform levels and haven't found any local
// minima. So, we'll just set the notch Position to the end
// of the chain.
notchPosition = chain.Length - tipPosition - 1;
}
if (notchPosition == 0)
{
// Now, we'll take the lowest few mins, and look at how
// they change over the transform levels.
double[] minVals = new double[mins.Count];
for (i = 0; i < mins.Count; i++)
{
minVals[i] = modMax[level, mins[i]];
}
Array.Sort(minVals);
int numMinsToTrack;
if ((int)mins.Count < NotchNumMinsToTrack)
{
numMinsToTrack = mins.Count;
}
else
{
numMinsToTrack = NotchNumMinsToTrack;
}
int[] positions = new int[numMinsToTrack];
for (int count = 0; count < numMinsToTrack; count++)
{
for (i = 0; i < mins.Count; i++)
{
if (minVals[count] == modMax[level, mins[i]])
{
positions[count] = mins[i];
break;
}
}
}
// Ok, now that we've got the few lowest mins,
// let's find their corresponding positions in
// a coarser level
int coarserLevel = TransformLevels - 2;
int correspondingPos;
//double alphaMax, alpha;
double difMax = 0.0, dif;
bool firstRun = true;
for (i = 0; i < numMinsToTrack; i++)
{
var extract = WaveletUtil.Extract1DArray(modMax, coarserLevel, numTrailingEdgePts);
correspondingPos = FindClosestMin(
5,
extract,
numTrailingEdgePts,
positions[i]);
// If we found a corresponding min in a coarser
// level...
if (-1 != correspondingPos)
{
//alpha = alphaK(
// level + 1,
// coarserLevel + 1,
// modMax[level][positions[i]],
// modMax[coarserLevel][correspondingPos]);
dif = Math.Abs(modMax[coarserLevel, correspondingPos]);
//+ fabs(modMax[level][positions[i]]);
if (firstRun)
{
firstRun = false;
difMax = dif;
notchPosition = positions[i];
}
else if (dif > difMax)
{
difMax = dif;
notchPosition = positions[i];
}
}
}
if (firstRun)
{
notchPosition = chain.Length - 1 - tipPosition;
}
}
/*
* list<ZeroCrossing> zeroCrossings =
* findZeroCrossings(continuousResult[level], numTrailingEdgePts);
*
* list<ZeroCrossing>::iterator it = zeroCrossings.begin();
*
* double maxDist = 0.0;
*
* while (it != zeroCrossings.end()) {
* if (it->leftMag < 0.0) {
* double curDist = (fabs(it->leftMag) + fabs(it->rightMag));
* if (curDist > maxDist) {
* maxDist = curDist;
* notchPosition = it->position;
* }
* }
++it;
* }
*
* zeroCrossings.clear();
*/
return(notchPosition + tipPosition);
}
//*******************************************************************
//
// int Outline::findTip()
//
// Finds the tip as the index into the chain array
//
public int FindTip(Chain chain, int highPointId, int highPointPaddingLeft = DefaultTipHighPointPadding, int highPointPaddingRight = DefaultTipHighPointPadding)
{
if (chain == null)
{
throw new Exception("findTip() [*_chain]");
}
// TODO
//if (_userSetTip)
// throw new Exception("findNotch() [User selected tip in use]");
int numPoints = chain.Length;
// First, make a copy without the first value in the chain,
// since the first value skews the rest of the chain and is
// unnecessary for our purposes here
double[] src = new double[numPoints - 1];
Array.Copy(chain.Data, 1, src, 0, numPoints - 1);
int nextPowOfTwo = MathHelper.NextPowerOfTwo(numPoints - 1);
// Now set up the variables needed to perform a wavelet transform on the chain
double[,] continuousResult = new double[TransformLevels + 1, nextPowOfTwo];
// Now perform the transformation
WIRWavelet.WL_FrwtVector(src,
ref continuousResult,
numPoints - 1,
TransformLevels,
WaveletUtil.MZLowPassFilter,
WaveletUtil.MZHighPassFilter);
int
tipPosition = 0,
level = TransformLevels;
/*
* while (!tipPosition && level > 0) { // Find the maxima of the
* coefficients double *modMax = new double[numPoints - 1];
*
* for (int k = 0; k < numPoints - 1; k++) continuousResult[level][k]
* *= normalizationCoeff(level);
*
* modulusMaxima(continuousResult[level], modMax, numPoints - 1);
*
* // Now, find the largest positive max, which we'll // assume is
* the tip of the fin.
*
* double max = modMax[0]; for (int i = 1; i < numPoints - 1; i++) {
* if (modMax[i] > max) { max = modMax[i]; tipPosition = i; } }
*
* level--; delete[] modMax; }
*/
while (level > 1)
{
// Find the maxima of the coefficients
double[] modMax = new double[numPoints - 1];
for (int k = 0; k < numPoints - 1; k++)
{
continuousResult[level, k] *= WaveletUtil.NormalizationCoeff(level);
}
double[] continousExtract = WaveletUtil.Extract1DArray(continuousResult, level, numPoints - 1);
WaveletUtil.ModulusMaxima(continousExtract, ref modMax, numPoints - 1);
// Now, find the largest positive max, which we'll
// assume is the tip of the fin.
if (tipPosition == 0)
{
// original loop control is two line below
//double max = modMax[0]; //***0041TIP-JHS restricting range of search
//for (int i = 1; i < numPoints - 1; i++) { //***0041TIP-JHS restricting range of search
//***0041TIP - we now restrict the range for initial detection of the tip
// start at high point on fin and search within 150 point range along fin
//***1.6 - NOTE: there is an unintended consequence of the limmits imposed
// below. If outlines are shortened to 50% or so of full size by having
// leading or trailing edges missing, the range of +/- 75 points is not
// a large enough range to capture tips of "MissingTip" fins in a consistent
// manner. We need to rethink this, and possibly go back to the original
// and retest against a database of fins traced without this limit.
// The new "Iterative, Tip Shifting" mapping approach probably conpensates
// for tip placement better than this limit on detection does. -- JHS (8/2/2006)
int initialIndex = highPointId - highPointPaddingLeft;
if (initialIndex < 0)
{
initialIndex = 0;
}
double max = modMax[initialIndex]; //***1.6 - removed temporarily for tests
int endIndex = highPointId + highPointPaddingRight;
if (endIndex >= modMax.Length)
{
endIndex = modMax.Length - 1;
}
for (int i = initialIndex; i < endIndex; i++)
{ //***1.6 - removed temporarily for tests
if (modMax[i] > max)
{
max = modMax[i];
tipPosition = i;
}
}
}
else
{
int maxSearchPoints = numPoints - 1;
if (highPointPaddingRight != DefaultTipHighPointPadding)
{
maxSearchPoints = highPointId + highPointPaddingRight;
}
// TODO: Left padding?
tipPosition = FindClosestMax(modMax, maxSearchPoints, tipPosition);
}
level--;
}
// Note that the actual tip position is +1 because we
// ignored the first value
Trace.WriteLine("Tip position: " + (tipPosition + 1));
if ((tipPosition + 1) < 5)
{
Trace.WriteLine("Probable bad tip position.");
}
return(tipPosition + 1);
}
/// <summary>
/// Tries to find the position of the upper lip on the outline. If there's a mouth dent,
/// it'll return that (and set the output parameter hasMouthDent to true). If there isn't,
/// it'll return the greatest max to the right of the mouth dent.
/// </summary>
/// <param name="chain"></param>
/// <param name="chainPoints"></param>
/// <param name="underNoseDentPosition"></param>
/// <param name="hasMouthDent"></param>
/// <param name="mouthDentPosition"></param>
/// <returns></returns>
public int FindUpperLip(Chain chain, FloatContour chainPoints, int underNoseDentPosition, out bool hasMouthDent, out int bottomLipProtrusion)
{
if (chain == null)
{
throw new ArgumentNullException(nameof(chain));
}
if (underNoseDentPosition < 0 || underNoseDentPosition > chain.Length)
{
throw new ArgumentOutOfRangeException(nameof(underNoseDentPosition));
}
hasMouthDent = false;
int numPointsAfterNoseDent = (int)Math.Round((chain.Length - underNoseDentPosition) * (1.0f - UpperLipEndPadding));
// We're going to transform the whole chain
int numPoints = chain.Length;
// First, make a copy without the first value in the chain,
// since the first value skews the rest of the chain and is
// unnecessary for our purposes here
double[] src = new double[numPoints - 1];
Array.Copy(chain.Data, 1, src, 0, numPoints - 1);
int nextPowOfTwo = MathHelper.NextPowerOfTwo(numPoints - 1);
// Now set up the variables needed to perform a wavelet transform on the chain
double[,] continuousResult = new double[UpperLipNumTransformsForMin + 1, nextPowOfTwo];
WIRWavelet.WL_FrwtVector(src,
ref continuousResult,
numPoints - 1,
UpperLipNumTransformsForMin,
WaveletUtil.MZLowPassFilter,
WaveletUtil.MZHighPassFilter);
for (int i = 1; i <= UpperLipNumTransformsForMin; i++)
{
for (int j = 0; j < numPoints - 1; j++)
{
continuousResult[i, j] *= WaveletUtil.NormalizationCoeff(i);
}
}
double[] modMax = new double[numPoints - 1];
for (int k = 0; k < numPoints - 1; k++)
{
continuousResult[UpperLipNumTransformsForMin, k] *= WaveletUtil.NormalizationCoeff(UpperLipNumTransformsForMin);
}
double[] continousExtract = WaveletUtil.Extract1DArray(continuousResult, UpperLipNumTransformsForMin, numPoints - 1);
WaveletUtil.ModulusMaxima(continousExtract, ref modMax, numPoints - 1);
// Now, let's see if we have any mins at the top transform level. If we do, we probably have a mouth dent. If we don't,
// we might not.
for (int k = numPointsAfterNoseDent + underNoseDentPosition; k > underNoseDentPosition; k--)
{
if (modMax[k] < 0.0)
{
hasMouthDent = true;
break;
}
}
int mouthDentPosition = 0;
if (hasMouthDent)
{
mouthDentPosition = FindNotch(chain, underNoseDentPosition + UpperLipTipPadding);
// Check where it found the mouth dent -- if it's too close to the end, it's likely that it's
// not the mouth, but something like the neck/etc.
if (mouthDentPosition < underNoseDentPosition + numPointsAfterNoseDent)
{
bottomLipProtrusion = FindTip(chain, mouthDentPosition + 20, mouthDentPosition - underNoseDentPosition - UpperLipTipPadding, UpperLipTipPadding);
return(mouthDentPosition);
}
}
// Fake the mouth dent position as a starting point for finding the biggest max in the area
mouthDentPosition = underNoseDentPosition + numPointsAfterNoseDent;
int upperLipPosition = FindTip(chain, mouthDentPosition, mouthDentPosition - underNoseDentPosition - UpperLipTipPadding, UpperLipTipPadding);
// These are fallback positions, so they're going to be off if we hit this if statement.
if (upperLipPosition < underNoseDentPosition)
{
upperLipPosition = (int)Math.Round(mouthDentPosition + numPointsAfterNoseDent / 2.0f);
}
bottomLipProtrusion = upperLipPosition;
return(upperLipPosition);
}
/// <summary>
/// Finds the Nasion, or the point on the head between the eyes. It does this by
/// finding the most significant minimum before the tip of the nose.
/// </summary>
/// <param name="chain"></param>
/// <param name="tipPosition">Index of the tip of the nose</param>
/// <returns>Integer index representing the position of the nasion</returns>
public int FindNasion(Chain chain, int tipPosition)
{
if (chain == null)
{
throw new ArgumentNullException(nameof(chain));
}
if (tipPosition < 0 || tipPosition > chain.Length)
{
throw new ArgumentOutOfRangeException(nameof(tipPosition));
}
int padding = (int)Math.Round(NasionPaddingPercentage * tipPosition);
int numPoints = chain.Length;
int numLeadingEdgePts = tipPosition - 2 * padding;
double[] src = new double[numLeadingEdgePts];
Array.Copy(chain.Data, padding, src, 0, numLeadingEdgePts);
int nextPowOfTwo = MathHelper.NextPowerOfTwo(numPoints - 1);
// Now set up the variables needed to perform a wavelet transform on the chain
double[,] continuousResult = new double[NasionTransformLevels + 1, nextPowOfTwo];
// Now perform the transformation
WIRWavelet.WL_FrwtVector(src,
ref continuousResult,
numLeadingEdgePts,
NasionTransformLevels,
WaveletUtil.MZLowPassFilter,
WaveletUtil.MZHighPassFilter);
int
nasionPosition = 0,
level = NasionTransformLevels;
while (level > 1)
{
// Find the maxima of the coefficients
double[] modMax = new double[numLeadingEdgePts];
for (int k = 0; k < numPoints - 1; k++)
{
continuousResult[level, k] *= WaveletUtil.NormalizationCoeff(level);
}
double[] continousExtract = WaveletUtil.Extract1DArray(continuousResult, level, numLeadingEdgePts);
WaveletUtil.ModulusMaxima(continousExtract, ref modMax, numLeadingEdgePts);
// Now, find the largest positive max, which we'll
// assume is the tip of the fin.
if (nasionPosition == 0)
{
// Find the greatest min
double min = double.MaxValue; //***1.6 - removed temporarily for tests
for (int i = 0; i < numLeadingEdgePts; i++)
{ //***1.6 - removed temporarily for tests
if (modMax[i] < min)
{
min = modMax[i];
nasionPosition = i;
}
}
}
else
{
var closestPosition = FindClosestMin(modMax, numLeadingEdgePts, nasionPosition);
if (closestPosition >= 0)
{
nasionPosition = closestPosition;
}
}
level--;
}
var correctedNasionPosition = nasionPosition + padding;
Trace.WriteLine("Nasion position: " + correctedNasionPosition);
if (correctedNasionPosition < 5)
{
Trace.WriteLine("Probable bad nasion position.");
}
return(correctedNasionPosition);
}