public override BitMatrix sampleGrid(BitMatrix image, int dimensionX, int dimensionY, PerspectiveTransform transform)
{
if (dimensionX <= 0 || dimensionY <= 0)
{
return null;
}
BitMatrix bits = new BitMatrix(dimensionX, dimensionY);
float[] points = new float[dimensionX << 1];
for (int y = 0; y < dimensionY; y++)
{
int max = points.Length;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float iValue = (float)y + 0.5f;
for (int x = 0; x < max; x += 2)
{
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
points[x] = (float)(x >> 1) + 0.5f;
points[x + 1] = iValue;
}
transform.transformPoints(points);
// Quick check to see if points transformed to something inside the image;
// sufficient to check the endpoints
if (!checkAndNudgePoints(image, points))
return null;
try
{
var imageWidth = image.Width;
var imageHeight = image.Height;
for (int x = 0; x < max; x += 2)
{
var imagex = (int)points[x];
var imagey = (int)points[x + 1];
if (imagex < 0 || imagex >= imageWidth || imagey < 0 || imagey >= imageHeight)
{
return null;
}
bits[x >> 1, y] = image[imagex, imagey];
}
}
catch (System.IndexOutOfRangeException)
{
// java version:
//
// This feels wrong, but, sometimes if the finder patterns are misidentified, the resulting
// transform gets "twisted" such that it maps a straight line of points to a set of points
// whose endpoints are in bounds, but others are not. There is probably some mathematical
// way to detect this about the transformation that I don't know yet.
// This results in an ugly runtime exception despite our clever checks above -- can't have
// that. We could check each point's coordinates but that feels duplicative. We settle for
// catching and wrapping ArrayIndexOutOfBoundsException.
return null;
}
}
return bits;
}
private static void assertPointEquals(float expectedX,
float expectedY,
float sourceX,
float sourceY,
PerspectiveTransform pt)
{
float[] points = { sourceX, sourceY };
pt.transformPoints(points);
Assert.AreEqual(expectedX, points[0], EPSILON);
Assert.AreEqual(expectedY, points[1], EPSILON);
}
/// <summary>
/// sampleGrid()
/// </summary>
/// <param name="image"></param>
/// <param name="dimensionX"></param>
/// <param name="dimensionY"></param>
/// <param name="transform"></param>
/// <returns></returns>
public override BitMatrix sampleGrid(BitMatrix image, int dimensionX, int dimensionY, PerspectiveTransform transform)
{
if (dimensionX <= 0 || dimensionY <= 0)
{
return(null);
}
BitMatrix bits = new BitMatrix(dimensionX, dimensionY);
float[] points = new float[dimensionX << 1];
for (int y = 0; y < dimensionY; y++)
{
int max = points.Length;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float iValue = (float)y + 0.5f;
for (int x = 0; x < max; x += 2)
{
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
points[x] = (float)(x >> 1) + 0.5f;
points[x + 1] = iValue;
}
transform.transformPoints(points);
// Quick check to see if points transformed to something inside the image;
// sufficient to check the endpoints
if (!checkAndNudgePoints(image, points))
{
return(null);
}
try
{
for (int x = 0; x < max; x += 2)
{
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
bits[x >> 1, y] = image[(int)points[x], (int)points[x + 1]];
}
}
catch (System.IndexOutOfRangeException)
{
// This feels wrong, but, sometimes if the finder patterns are misidentified, the resulting
// transform gets "twisted" such that it maps a straight line of points to a set of points
// whose endpoints are in bounds, but others are not. There is probably some mathematical
// way to detect this about the transformation that I don't know yet.
// This results in an ugly runtime exception despite our clever checks above -- can't have
// that. We could check each point's coordinates but that feels duplicative. We settle for
// catching and wrapping ArrayIndexOutOfBoundsException.
return(null);
}
}
return(bits);
}
