/// <summary>
/// Bilinearly Interpolate the filtered image to keep visual smoothness and avoid edgy effect
/// </summary>
private IImageAdapter Interp(IImageAdapter iiad)
{
ImageAdapter retVal = new ImageAdapter(iiad);
int llLength = (int)Math.Pow(2, Level);
double wexpFactor = (double)(iiad.Width - 4 * Level) / ((iiad.Width) * llLength);
double hexpFactor = (double)(iiad.Height - 4 * Level) / ((iiad.Height) * llLength);
for (int j = 0; j < iiad.Height; j++)
{
for (int i = 0; i < iiad.Width; i++)
{
double x = (double)i * wexpFactor;
double y = (double)j * hexpFactor;
retVal[i, j] = BilinearInterpolator.ProcessPoint(x, y, iiad, null);
}
}
return(retVal);
}
/// <summary>
/// Apply the transform using the supplied matrix
/// </summary>
/// <param name="matrix">the matrix to be applied (format if x1,y1,x2,y2,t1,t2)</param>
public void Transform(Matrix2D matrix)
{
if (_imageSource == null)
{
throw new RenderingVerificationException("ImageSource not Assigned, cannot transform a unknow image");
}
if (matrix == null)
{
throw new ArgumentException("Invalid argument passed in, must be a valid instance (not set to null) of Matrix2D or an array of double of length " + Matrix2D.Length);
}
if (matrix.IsInvertible == false)
{
throw new Matrix2DException("Matrix passed in is not inversible, cannot transform using this matrix (matrix passed in : )" + matrix.ToString());
}
if (matrix.IsIdentity)
{
_imageTransformed = (IImageAdapter)_imageSource.Clone();
return;
}
// Create the IImageAdapter to return
int width = _imageSource.Width;
int height = _imageSource.Height;
if (_resizeToFitOutputImage)
{
double x = 0.0;
double y = 0.0;
Point topLeft = new Point((int)(x + Math.Sign(x) * 0.5), (int)(y + Math.Sign(y) * 0.5));
x = matrix.X1 * width;
y = matrix.X2 * width;
Point topRight = new Point((int)(x + Math.Sign(x) * 0.5), (int)(y + Math.Sign(y) * 0.5));
x = matrix.X1 * width + matrix.Y1 * height;
y = matrix.X2 * width + matrix.Y2 * height;
Point bottomRight = new Point((int)(x + Math.Sign(x) * 0.5), (int)(y + Math.Sign(y) * 0.5));
x = matrix.Y1 * height;
y = matrix.Y2 * height;
Point bottomLeft = new Point((int)(x + Math.Sign(x) * 0.5), (int)(y + Math.Sign(y) * 0.5));
width = (int)Math.Max(Math.Abs(bottomRight.X - topLeft.X), Math.Abs(topRight.X - bottomLeft.X));
height = (int)Math.Max(Math.Abs(bottomRight.Y - topLeft.Y), Math.Abs(topRight.Y - bottomLeft.Y));
}
_imageTransformed = new ImageAdapter(width, height, _unassignedColor);
// Scale down imnage if needed (average pixels)
//
double horizontalScaling = double.NaN;
if (matrix.X1 != 0)
{
horizontalScaling = Math.Sqrt(Math.Abs(matrix.Determinant * matrix.Y2 / matrix.X1));
}
else
{
horizontalScaling = Math.Sqrt(Math.Abs(matrix.Determinant * matrix.Y1 / matrix.X2));
}
double verticalScaling = Math.Sqrt(matrix.Determinant / horizontalScaling);
IImageAdapter scaledImage = BilinearInterpolator.ScaleDown(horizontalScaling, verticalScaling, _imageSource);
// Interpolate image (if scaling up and/or rotation applied to image)
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
double ix = 0.0;
double iy = 0.0;
ConvertCoordinates(matrix, x, y, out ix, out iy);
_imageTransformed[x, y] = _interpolationMethod(ix, iy, scaledImage, _unassignedColor);
}
}
}