void MaskedImage::maskedInterpolate(const UArray<double> & xs, const UArray<double> & ys, UArray<double> & outValues, UArray<bool> & outMask) const
{
U_ASSERT((xs.getSize() == ys.getSize()) && (xs.getSize() == outValues.getSize()) && (xs.getSize() == outMask.getSize()));
static double cubicSplineMatrix[4*4] =
{0, 1, 0, 0,
-0.5, 0, 0.5, 0,
1, -2.5, 2, -0.5,
-0.5, 1.5, -1.5, 0.5};
double xPowers[4];
double yPowers[4];
xPowers[0] = 1.0;
yPowers[0] = 1.0;
for(SInt32 dataIndex = 0; dataIndex < xs.getSize(); dataIndex++)
{
double x = (xs[dataIndex]- getXLower())/getDeltaX();
double y = (ys[dataIndex]- getYLower())/getDeltaY();
SInt32 xIndex = (SInt32)x;
SInt32 yIndex = (SInt32)y;
// if the index is too close to the edge, extrapolate from the nearest location inbounds
if((xIndex < 1) || (xIndex > getXSize()-3)
|| (yIndex < 1) || (yIndex > getYSize()-3))
{
outMask[dataIndex] = false;
continue;
}
outMask[dataIndex] = true;
for(SInt32 j = 0; j < 4; j++)
{
for(SInt32 i = 0; i < 4; i++)
{
outMask[dataIndex] = outMask[dataIndex] && getMask(xIndex + i - 1,yIndex + j - 1);
}
}
if(!outMask[dataIndex])
continue;
x = x - (double)xIndex;
y = y - (double)yIndex;
xPowers[1] = x;
xPowers[2] = x*x;
xPowers[3] = x*x*x;
yPowers[1] = y;
yPowers[2] = y*y;
yPowers[3] = y*y*y;
double result = 0;
for(SInt32 k = 0; k < 4; k++)
{
double localResult = 0;
for(SInt32 j = 0; j < 4; j++)
for(SInt32 i = 0; i < 4; i++)
localResult = localResult + xPowers[i]*cubicSplineMatrix[j+4*i]*(*this)(xIndex + j - 1, yIndex + k - 1);
for(SInt32 i = 0; i < 4; i++)
result = result + yPowers[i]*cubicSplineMatrix[k+4*i]*localResult;
}
outValues[dataIndex] = result;
}
}
void MaskedImage::maskedInterpolateAtOffsetPixels(double xLower, double yLower, SInt32 xCount, SInt32 yCount,
UArray<double> & outValues, UArray<bool> & outMask) const
{
U_ASSERT((xCount*yCount == outValues.getSize()) && (xCount*yCount == outMask.getSize()));
static double cubicSplineMatrix[4*4] =
{0, 1, 0, 0,
-0.5, 0, 0.5, 0,
1, -2.5, 2, -0.5,
-0.5, 1.5, -1.5, 0.5};
double xPowers[4];
double yPowers[4];
xPowers[0] = 1.0;
yPowers[0] = 1.0;
double x = (xLower - getXLower())/getDeltaX();
double y = (yLower - getYLower())/getDeltaY();
SInt32 xLowerIndex = (SInt32)x;
SInt32 yLowerIndex = (SInt32)y;
x = x - (double)xLowerIndex;
y = y - (double)yLowerIndex;
xPowers[1] = x;
xPowers[2] = x*x;
xPowers[3] = x*x*x;
yPowers[1] = y;
yPowers[2] = y*y;
yPowers[3] = y*y*y;
double coefficients[4*4];
for(SInt32 i = 0; i < 16; i++)
coefficients[i] = 0;
for(SInt32 k = 0; k < 4; k++)
{
for(SInt32 j = 0; j < 4; j++)
{
double result = 0;
for(SInt32 l = 0; l < 4; l++)
for(SInt32 i = 0; i < 4; i++)
result = result + xPowers[i]*cubicSplineMatrix[j+4*i]*yPowers[l]*cubicSplineMatrix[k+4*l];
coefficients[j+4*k] = result;
}
}
SInt32 dataIndex = 0;
for(SInt32 yIndex = yLowerIndex; yIndex < yLowerIndex+yCount; yIndex++)
{
for(SInt32 xIndex = xLowerIndex; xIndex < xLowerIndex+xCount; xIndex++)
{
// if the index is too close to the edge
if((xIndex < 1) || (xIndex > getXSize()-3)
|| (yIndex < 1) || (yIndex > getYSize()-3))
{
outMask[dataIndex] = false;
dataIndex++;
continue;
}
outMask[dataIndex] = true;
for(SInt32 j = 0; j < 4; j++)
{
for(SInt32 i = 0; i < 4; i++)
{
outMask[dataIndex] = outMask[dataIndex] && getMask(xIndex + i - 1,yIndex + j - 1);
}
}
if(!outMask[dataIndex])
{
dataIndex++;
continue;
}
double result = 0;
for(SInt32 k = 0; k < 4; k++)
for(SInt32 j = 0; j < 4; j++)
result = result + coefficients[j+4*k]*(*this)(xIndex + j - 1, yIndex + k - 1);
outValues[dataIndex] = result;
dataIndex++;
}
}
}
int Accelerometer::getAbsDeltaY() {
return abs(getDeltaY());
}
