public ArrayData houghTransform(ArrayData originalImage, int thetaAxisSize, int rAxisSize, int minContrast)
{
int width = originalImage.width;
int height = originalImage.height;
int maxRadius = (int)Math.Ceiling(hypotenuse(width, height));
int halfRAxisSize = rAxisSize >> 1;
var outputImage = new ArrayData(thetaAxisSize, rAxisSize);
// x output ranges from 0 to pi
// y output ranges from -maxRadius to maxRadius
double[] sinTable = new double[thetaAxisSize];
double[] cosTable = new double[thetaAxisSize];
for (int theta = thetaAxisSize - 1; theta >= 0; theta--)
{
double thetaRadians = theta * Math.PI / thetaAxisSize;
sinTable[theta] = Math.Sin(thetaRadians);
cosTable[theta] = Math.Cos(thetaRadians);
}
for (int y = height - 1; y >= 0; y--)
{
for (int x = width - 1; x >= 0; x--)
{
if (originalImage.contrast(x, y, minContrast))
{
for (int theta = thetaAxisSize - 1; theta >= 0; theta--)
{
double r = cosTable[theta] * x + sinTable[theta] * y;
int rScaled = (int)Math.Round(r * halfRAxisSize / maxRadius) + halfRAxisSize;
outputImage.accumulate(theta, rScaled, 1);
}
}
}
}
return(outputImage);
}
public ArrayData houghTransform(ArrayData originalImage, int thetaAxisSize, int rAxisSize, int minContrast)
{
int width = originalImage.width;
int height = originalImage.height;
int maxRadius = (int)Math.Ceiling(hypotenuse(width, height));
int halfRAxisSize = rAxisSize >> 1;
var outputImage = new ArrayData(thetaAxisSize, rAxisSize);
// x output ranges from 0 to pi
// y output ranges from -maxRadius to maxRadius
double[] sinTable = new double[thetaAxisSize];
double[] cosTable = new double[thetaAxisSize];
for (int theta = thetaAxisSize - 1; theta >= 0; theta--)
{
double thetaRadians = theta * Math.PI / thetaAxisSize;
sinTable[theta] = Math.Sin(thetaRadians);
cosTable[theta] = Math.Cos(thetaRadians);
}
for (int y = height - 1; y >= 0; y--)
{
for (int x = width - 1; x >= 0; x--)
{
if (originalImage.contrast(x, y, minContrast))
{
for (int theta = thetaAxisSize - 1; theta >= 0; theta--)
{
double r = cosTable[theta] * x + sinTable[theta] * y;
int rScaled = (int)Math.Round(r * halfRAxisSize / maxRadius) + halfRAxisSize;
outputImage.accumulate(theta, rScaled, 1);
}
}
}
}
return outputImage;
}
