internal static List <PotentialStarStruct> GetPeakPixelsInArea(
uint[,] data, out uint[,] lpdData, int bpp, uint maxSignalValue, uint aboveNoiseLevelRequired,
double minDistanceInPixels, bool useLPDFilter, Rectangle excludeArea)
{
if (useLPDFilter)
{
lpdData = ImageFilters.LowPassDifferenceFilter(data, bpp, false);
}
else
{
lpdData = data;
}
int nWidth = lpdData.GetLength(0);
int nHeight = lpdData.GetLength(1);
List <PotentialStarStruct> potentialStars = new List <PotentialStarStruct>();
ExaminePeakPixelCandidate examinePixelCallback =
delegate(int x, int y, uint z)
{
bool tooClose = false;
// Local maximum, test for a star
foreach (PotentialStarStruct prevStar in potentialStars)
{
double dist =
Math.Sqrt((prevStar.X - x) * (prevStar.X - x) +
(prevStar.Y - y) * (prevStar.Y - y));
if (dist <= minDistanceInPixels)
{
tooClose = true;
if (prevStar.Z < z)
{
prevStar.Z = z;
prevStar.X = x;
prevStar.Y = y;
}
break;
}
}
if (!tooClose)
{
potentialStars.Add(new PotentialStarStruct()
{
X = x, Y = y, Z = z
});
}
// An early return if too many peak pixels have been found
return(potentialStars.Count <=
TangraConfig.Settings.Special.
StarFinderMaxNumberOfPotentialStars);
};
if (useLPDFilter)
{
CheckAllPixels(lpdData, nWidth, nHeight, aboveNoiseLevelRequired, excludeArea, examinePixelCallback);
}
else
{
CheckPixelsFromBrightToFaint(lpdData, nWidth, nHeight, bpp, maxSignalValue, aboveNoiseLevelRequired, excludeArea, examinePixelCallback);
}
return(potentialStars);
}
private static void CheckPixelsFromBrightToFaint(
uint[,] data, int nWidth, int nHeight, int bpp, uint maxSignalValue, uint aboveNoiseLevelRequired, Rectangle excludeArea, ExaminePeakPixelCandidate callback)
{
bool excludeAreaDefined = Rectangle.Empty != excludeArea;
int includsionCheckStep = 10;
if (bpp == 12)
{
includsionCheckStep = 50;
}
else if (bpp == 14)
{
includsionCheckStep = 60;
}
else if (bpp == 16)
{
includsionCheckStep = 100;
}
int maxPixelValue = 255;
if (bpp > 8)
{
maxPixelValue = (int)maxSignalValue;
}
int currInclusionLimit = maxPixelValue - includsionCheckStep + 1;
while (currInclusionLimit > aboveNoiseLevelRequired)
{
for (int i = 1; i < nWidth - 1; i++)
{
for (int j = 1; j < nHeight - 1; j++)
{
if (excludeAreaDefined && excludeArea.Contains(i, j))
{
continue;
}
uint testedPixel = data[i, j];
if (testedPixel > currInclusionLimit &&
testedPixel <= currInclusionLimit + includsionCheckStep &&
testedPixel >= data[i - 1, j] &&
testedPixel >= data[i - 1, j - 1] &&
testedPixel >= data[i, j - 1] &&
testedPixel >= data[i + 1, j - 1] &&
testedPixel >= data[i + 1, j] &&
testedPixel >= data[i + 1, j + 1] &&
testedPixel >= data[i, j + 1] &&
testedPixel >= data[i - 1, j + 1])
{
if (!callback(i, j, testedPixel))
{
return;
}
}
}
}
currInclusionLimit -= includsionCheckStep;
}
}
private static void CheckPixelsFromBrightToFaint(
uint[,] data, int nWidth, int nHeight, int bpp, uint maxSignalValue, uint aboveNoiseLevelRequired, Rectangle excludeArea, ExaminePeakPixelCandidate callback)
{
bool excludeAreaDefined = Rectangle.Empty != excludeArea;
int includsionCheckStep = 10;
if (bpp == 12) includsionCheckStep = 50;
else if (bpp == 14) includsionCheckStep = 60;
else if (bpp == 16) includsionCheckStep = 100;
int maxPixelValue = 255;
if (bpp > 8) maxPixelValue = (int)maxSignalValue;
int currInclusionLimit = maxPixelValue - includsionCheckStep + 1;
while (currInclusionLimit > aboveNoiseLevelRequired)
{
for (int i = 1; i < nWidth - 1; i++)
for (int j = 1; j < nHeight - 1; j++)
{
if (excludeAreaDefined && excludeArea.Contains(i, j))
continue;
uint testedPixel = data[i, j];
if (testedPixel > currInclusionLimit &&
testedPixel <= currInclusionLimit + includsionCheckStep &&
testedPixel >= data[i - 1, j] &&
testedPixel >= data[i - 1, j - 1] &&
testedPixel >= data[i, j - 1] &&
testedPixel >= data[i + 1, j - 1] &&
testedPixel >= data[i + 1, j] &&
testedPixel >= data[i + 1, j + 1] &&
testedPixel >= data[i, j + 1] &&
testedPixel >= data[i - 1, j + 1])
{
if (!callback(i, j, testedPixel))
return;
}
}
currInclusionLimit -= includsionCheckStep;
}
}
private static void CheckAllPixels(uint[,] data, int nWidth, int nHeight, uint aboveNoiseLevelRequired, Rectangle excludeArea, ExaminePeakPixelCandidate callback)
{
bool excludeAreaDefined = Rectangle.Empty != excludeArea;
for (int i = 1; i < nWidth - 1; i++)
{
for (int j = 1; j < nHeight - 1; j++)
{
if (excludeAreaDefined && excludeArea.Contains(i, j))
{
continue;
}
uint testedPixel = data[i, j];
if (testedPixel > aboveNoiseLevelRequired &&
testedPixel >= data[i - 1, j] &&
testedPixel >= data[i - 1, j - 1] &&
testedPixel >= data[i, j - 1] &&
testedPixel >= data[i + 1, j - 1] &&
testedPixel >= data[i + 1, j] &&
testedPixel >= data[i + 1, j + 1] &&
testedPixel >= data[i, j + 1] &&
testedPixel >= data[i - 1, j + 1])
{
if (!callback(i, j, testedPixel))
{
return;
}
}
}
}
}
private static void CheckAllPixels(uint[,] data, int nWidth, int nHeight, uint aboveNoiseLevelRequired, Rectangle excludeArea, ExaminePeakPixelCandidate callback)
{
bool excludeAreaDefined = Rectangle.Empty != excludeArea;
for (int i = 1; i < nWidth - 1; i++)
for (int j = 1; j < nHeight - 1; j++)
{
if (excludeAreaDefined && excludeArea.Contains(i, j))
continue;
uint testedPixel = data[i, j];
if (testedPixel > aboveNoiseLevelRequired &&
testedPixel >= data[i - 1, j] &&
testedPixel >= data[i - 1, j - 1] &&
testedPixel >= data[i, j - 1] &&
testedPixel >= data[i + 1, j - 1] &&
testedPixel >= data[i + 1, j] &&
testedPixel >= data[i + 1, j + 1] &&
testedPixel >= data[i, j + 1] &&
testedPixel >= data[i - 1, j + 1])
{
if (!callback(i, j, testedPixel))
return;
}
}
}