/// <summary>
/// Slides a window with a subwindow with sizes specified by the input parameters over the frame. The average depth in the windows are compared and if above a certain threshold considered to be head candidates.
/// </summary>
private List <int> SlideWindow(int outerWindowWidth, int innerWindowWidth, float windowDifferenceThreshold)
{
var candidates = new List <int>();
int marginInnerWindow = (outerWindowWidth - innerWindowWidth) / 2;
int innerWindowArea = innerWindowWidth * innerWindowWidth;
for (int i = 0; i < GlobVar.ScaledFrameHeight - innerWindowWidth; i += 2)
{
for (int j = 0; j < GlobVar.ScaledFrameWidth - innerWindowWidth; j += 2)
{
int outerWindowHeight = outerWindowWidth;
int outerWindowTempWidth = outerWindowWidth;
int iOuter = i - marginInnerWindow;
int jOuter = j - marginInnerWindow;
if (iOuter < 0)
{
outerWindowHeight += iOuter;
iOuter = 0;
}
if (jOuter < 0)
{
outerWindowTempWidth += jOuter;
jOuter = 0;
}
if (iOuter + outerWindowWidth > GlobVar.ScaledFrameHeight - 1)
{
outerWindowHeight += iOuter + outerWindowWidth - GlobVar.ScaledFrameHeight - 1;
iOuter = GlobVar.ScaledFrameHeight - 1 - outerWindowHeight;
}
if (jOuter + outerWindowWidth > GlobVar.ScaledFrameWidth - 1)
{
outerWindowTempWidth += jOuter + outerWindowWidth - GlobVar.ScaledFrameWidth - 1;
jOuter = GlobVar.ScaledFrameWidth - 1 - outerWindowTempWidth;
}
int innerIndexA = GlobUtils.GetIndex(j, i);
int innerIndexB = GlobUtils.GetIndex(j + innerWindowWidth, i);
int innerIndexC = GlobUtils.GetIndex(j, i + innerWindowWidth);
int innerIndexD = GlobUtils.GetIndex(j + innerWindowWidth, i + innerWindowWidth);
int outerIndexA = GlobUtils.GetIndex(jOuter, iOuter);
int outerIndexB = GlobUtils.GetIndex(jOuter + outerWindowTempWidth, iOuter);
int outerIndexC = GlobUtils.GetIndex(jOuter, iOuter + outerWindowHeight);
int outerIndexD = GlobUtils.GetIndex(jOuter + outerWindowTempWidth, iOuter + outerWindowHeight);
int outerWindowArea = GlobUtils.CalculateRectangleAreaFromIndexes(outerIndexA, outerIndexB, outerIndexC);
float sumInnerWindow = (_integralImage[innerIndexA] + _integralImage[innerIndexD] -
_integralImage[innerIndexB] - _integralImage[innerIndexC]);
float sumOuterWindow = (_integralImage[outerIndexA] + _integralImage[outerIndexD] -
_integralImage[outerIndexB] - _integralImage[outerIndexC]);
float averageInnerWindow = sumInnerWindow / innerWindowArea;
if (averageInnerWindow > GlobVar.MaxSensingDepth - Thresholds.HaarDetectionHeightHeadMin)
{
continue;
}
float averageOuterWindow = (sumOuterWindow - sumInnerWindow) / (outerWindowArea - innerWindowArea);
if ((averageOuterWindow - averageInnerWindow) > windowDifferenceThreshold)
{
int candidate = GlobUtils.GetHighestValidPointIndexInRectangle(innerIndexB, innerIndexC);
candidates.Add(candidate);
if (Logger.ShowHaarInnerRects)
{
GraphicsUtils.DrawRectangle(new IndexRectangle(innerIndexA, innerIndexB, innerIndexC));
}
if (Logger.ShowHaarOuterRects)
{
GraphicsUtils.DrawRectangle(new IndexRectangle(outerIndexA, outerIndexB, outerIndexC));
}
}
}
}
return(candidates);
}
