private void initalizeHistograms()
{
int[] binSizes = new int[] { 32, 32 }; //X bins per channel
IntRange[] ranges = new IntRange[]
{
new IntRange(0, 180), //Hue (for 8bpp image hue>> range is (0-180) otherwise (0-360)
new IntRange(0, 255)
};
originalObjHist = new DenseHistogram(binSizes, ranges);
backgroundHist = originalObjHist.CopyBlank();
}
/// <summary>
/// Finds humps in contour. Hump scale is determined by <paramref name="scale"/>.
/// <para>For each peak a closest valley is found. Next for that valley a closet point is found. Those three point make hump.</para>
/// <para>Hump searching will be successful even when only one peak and one valley are found; it can be successful where peak and valley search against convex hull does not give good results.</para>
/// <para></para>Peaks and valleys can be obtained by using <see cref="FindExtremaIndices"/>.
/// </summary>
/// <param name="contour">Contour.</param>
/// <param name="peaks">Peaks.</param>
/// <param name="valeys">Valleys.</param>
/// <param name="scale">Used for <see cref="GetClosestPoint"/>. A good value is ~20. A specified region will be searched every time to avoid local minimum.</param>
/// <param name="humpPeaks">Found hump peaks.</param>
/// <returns>Humps contour indexes.</returns>
public static List <Range> GetHumps(this IList <Point> contour, List <int> peaks, List <int> valeys, int scale, out List <int> humpPeaks)
{
List <Range> humps = new List <Range>();
humpPeaks = new List <int>();
if (valeys.Count == 0)
{
return(humps);
}
foreach (var peak in peaks)
{
var closestValey = valeys.MinBy(valey => System.Math.Abs(valey - peak));
var searchDirection = ((peak - closestValey) > 0) ? 1 : -1;
int closestPtToValey = contour.GetClosestPoint(closestValey, peak, searchDirection, scale);
if (closestPtToValey == closestValey) //skip "humps" with zero elements
{
continue;
}
Range hump;
if (searchDirection < 0)
{
hump = new Range(closestPtToValey, closestValey);
}
else
{
hump = new Range(closestValey, closestPtToValey);
}
//check if a hump contain some other peaks and valey; classify it as a bad hump
if (hump.IsInside(peaks).Count(x => x == true) > 1 ||/*discard the current peak*/
hump.IsInside(valeys).Count(x => x == true) > 1)
{
}
else
{
humps.Add(hump);
humpPeaks.Add(peak);
}
}
return(humps);
}
/// <summary>
/// Gets closest point to the <paramref name="ptIdx"/>.
/// </summary>
/// <param name="contour">Contour.</param>
/// <param name="ptIdx">Point index for which to find the closest point.</param>
/// <param name="searchSegment">Contour segment to search.</param>
/// <param name="distance">Distance from <paramref name="ptIdx"/> to returned point index.</param>
/// <returns>Closest point index regarding <paramref name="ptIdx"/>.</returns>
public static int GetClosestPoint(this IList <Point> contour, int ptIdx, Range searchSegment, out double distance)
{
double minDist = Double.MaxValue;
int closestPt = -1;
Point pt = contour[ptIdx];
int idx = (int)searchSegment.Min;
while (idx != (int)searchSegment.Max)
{
var dist = ((PointF)pt).DistanceTo(contour[idx]);
if (dist < minDist)
{
minDist = dist;
closestPt = idx;
}
idx = (idx + 1) % contour.Count;
}
distance = minDist;
return(closestPt);
}
/// <summary>
/// Finds humps in contour. Hump scale is determined by <paramref name="scale"/>.
/// <para>For each peak a closest valley is found. Next for that valley a closet point is found. Those three point make hump.</para>
/// <para>Hump searching will be successful even when only one peak and one valley are found; it can be successful where peak and valley search against convex hull does not give good results.</para>
/// <para></para>Peaks and valleys can be obtained by using <see cref="FindExtremaIndices"/>.
/// </summary>
/// <param name="contour">Contour.</param>
/// <param name="peaks">Peaks.</param>
/// <param name="valeys">Valleys.</param>
/// <param name="scale">Used for <see cref="GetClosestPoint"/>. A good value is ~20. A specified region will be searched every time to avoid local minimum.</param>
/// <param name="humpPeaks">Found hump peaks.</param>
/// <returns>Humps contour indexes.</returns>
public static List<Range> GetHumps(this IList<Point> contour, List<int> peaks, List<int> valeys, int scale, out List<int> humpPeaks)
{
List<Range> humps = new List<Range>();
humpPeaks = new List<int>();
if (valeys.Count == 0) return humps;
foreach (var peak in peaks)
{
var closestValey = valeys.MinBy(valey => System.Math.Abs(valey - peak));
var searchDirection = ((peak - closestValey) > 0) ? 1 : -1;
int closestPtToValey = contour.GetClosestPoint(closestValey, peak, searchDirection, scale);
if (closestPtToValey == closestValey) //skip "humps" with zero elements
continue;
Range hump;
if (searchDirection < 0)
hump = new Range(closestPtToValey, closestValey);
else
hump = new Range(closestValey, closestPtToValey);
//check if a hump contain some other peaks and valey; classify it as a bad hump
if (hump.IsInside(peaks).Count(x => x == true) > 1 ||/*discard the current peak*/
hump.IsInside(valeys).Count(x => x == true) > 1)
{ }
else
{
humps.Add(hump);
humpPeaks.Add(peak);
}
}
return humps;
}
/// <summary>
/// Gets closest point to the <paramref name="ptIdx"/>.
/// </summary>
/// <param name="contour">Contour.</param>
/// <param name="ptIdx">Point index for which to find the closest point.</param>
/// <param name="searchSegment">Contour segment to search.</param>
/// <param name="distance">Distance from <paramref name="ptIdx"/> to returned point index.</param>
/// <returns>Closest point index regarding <paramref name="ptIdx"/>.</returns>
public static int GetClosestPoint(this IList<Point> contour, int ptIdx, Range searchSegment, out double distance)
{
double minDist = Double.MaxValue;
int closestPt = -1;
Point pt = contour[ptIdx];
int idx = (int)searchSegment.Min;
while (idx != (int)searchSegment.Max)
{
var dist = ((PointF)pt).DistanceTo(contour[idx]);
if (dist < minDist)
{
minDist = dist;
closestPt = idx;
}
idx = (idx + 1) % contour.Count;
}
distance = minDist;
return closestPt;
}
