/*
* Based on Craig's Utility Library (CUL) by James Craig.
* http://www.gutgames.com/post/Edge-detection-in-C.aspx
* MIT License (http://www.opensource.org/licenses/mit-license.php)
*/
/// <summary>
/// Gets a new bitmap containing edges detected in source bitmap.
/// The source bitmap is unchanged.
/// </summary>
/// <param name="bitmap">DFBitmap source.</param>
/// <param name="threshold">Edge detection threshold.</param>
/// <param name="edgeColor">Edge colour to write.</param>
/// <returns>DFBitmap containing edges.</returns>
private static DFBitmap FindEdges(DFBitmap bitmap, float threshold, DFBitmap.DFColor edgeColor)
{
// Must be a colour format
if (bitmap.Format == DFBitmap.Formats.Indexed)
{
return(null);
}
// Clone bitmap settings
DFBitmap newBitmap = DFBitmap.CloneDFBitmap(bitmap);
for (int x = 0; x < bitmap.Width; x++)
{
for (int y = 0; y < bitmap.Height; y++)
{
DFBitmap.DFColor currentColor = DFBitmap.GetPixel(bitmap, x, y);
if (y < newBitmap.Height - 1 && x < newBitmap.Width - 1)
{
DFBitmap.DFColor tempColor = DFBitmap.GetPixel(bitmap, x + 1, y + 1);
if (ColorDistance(currentColor, tempColor) > threshold)
{
DFBitmap.SetPixel(newBitmap, x, y, edgeColor);
}
}
else if (y < newBitmap.Height - 1)
{
DFBitmap.DFColor tempColor = DFBitmap.GetPixel(bitmap, x, y + 1);
if (ColorDistance(currentColor, tempColor) > threshold)
{
DFBitmap.SetPixel(newBitmap, x, y, edgeColor);
}
}
else if (x < newBitmap.Width - 1)
{
DFBitmap.DFColor tempColor = DFBitmap.GetPixel(bitmap, x + 1, y);
if (ColorDistance(currentColor, tempColor) > threshold)
{
DFBitmap.SetPixel(newBitmap, x, y, edgeColor);
}
}
}
}
return(newBitmap);
}
/// <summary>
/// Applies the filter to the input image
/// </summary>
/// <param name="Input">input image</param>
/// <returns>Returns a separate image with the filter applied</returns>
public DFBitmap ApplyFilter(DFBitmap Input)
{
// Must be a colour format
if (Input.Format == DFBitmap.Formats.Indexed)
{
return(null);
}
DFBitmap NewBitmap = DFBitmap.CloneDFBitmap(Input);
for (int x = 0; x < Input.Width; ++x)
{
for (int y = 0; y < Input.Height; ++y)
{
int RValue = 0;
int GValue = 0;
int BValue = 0;
int AValue = 0;
int Weight = 0;
int XCurrent = -Width / 2;
for (int x2 = 0; x2 < Width; ++x2)
{
if (XCurrent + x < Input.Width && XCurrent + x >= 0)
{
int YCurrent = -Height / 2;
for (int y2 = 0; y2 < Height; ++y2)
{
if (YCurrent + y < Input.Height && YCurrent + y >= 0)
{
DFBitmap.DFColor Pixel = DFBitmap.GetPixel(Input, XCurrent + x, YCurrent + y);
RValue += MyFilter[x2, y2] * Pixel.r;
GValue += MyFilter[x2, y2] * Pixel.g;
BValue += MyFilter[x2, y2] * Pixel.b;
AValue = Pixel.a;
Weight += MyFilter[x2, y2];
}
++YCurrent;
}
}
++XCurrent;
}
DFBitmap.DFColor MeanPixel = DFBitmap.GetPixel(Input, x, y);
if (Weight == 0)
{
Weight = 1;
}
if (Weight > 0)
{
if (Absolute)
{
RValue = System.Math.Abs(RValue);
GValue = System.Math.Abs(GValue);
BValue = System.Math.Abs(BValue);
}
RValue = (RValue / Weight) + Offset;
RValue = Clamp(RValue, 0, 255);
GValue = (GValue / Weight) + Offset;
GValue = Clamp(GValue, 0, 255);
BValue = (BValue / Weight) + Offset;
BValue = Clamp(BValue, 0, 255);
MeanPixel = DFBitmap.DFColor.FromRGBA((byte)RValue, (byte)GValue, (byte)BValue, (byte)AValue);
}
DFBitmap.SetPixel(NewBitmap, x, y, MeanPixel);
}
}
return(NewBitmap);
}
