/// <summary>
///
/// Produces a binary Matrix with Dimensions
/// For the threshold, we take the sum of weighted R,g,b value. The sum of weights must be 1.
/// The result fills the field bm;
/// </summary>
/// <param name="bitmap"> A Bitmap, which will be transformed to a binary Matrix</param>
/// <returns>Returns a binaray boolean Matrix </returns>
void ConvertBitmap(Bitmap bitmap)
{
byte[] Result = new byte[bitmap.Width * bitmap.Height];
BitmapData SourceData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
unsafe
{
byte *SourcePtr = (byte *)(void *)SourceData.Scan0;
int l = Result.Length;
for (int i = 0; i < l; i++)
{
// if ((0.2126 * (double)SourcePtr[4 * i + 2] + 0.7153 * (double)SourcePtr[4 * i + 1] + 0.0721 * (double)SourcePtr[4 * i]) < Treshold*255)
if (((double)SourcePtr[4 * i + 2] + (double)SourcePtr[4 * i + 1] + (double)SourcePtr[4 * i]) < Treshold * 255 * 3)
{
Result[i] = 1;
}
else
{
Result[i] = 0;
}
}
}
bitmap.UnlockBits(SourceData);
bm = new Bitmap_p(bitmap.Width, bitmap.Height);
bm.data = Result;
}
/// <summary>
/// Decompose the given bitmap into paths. Returns a linked list of
/// Path objects with the fields len, pt, area filled
/// </summary>
/// <param name="bm">A binary bitmap which holds the imageinformations.</param>
/// <param name="plistp">List of Path objects</param>
Path bmToPathlist()
{
Bitmap_p bm1 = bm.copy();
Point currentPoint = new Point(0, 0);
Path path = new Path();
bool weiter = findNext(bm1, currentPoint, ref currentPoint);
while (weiter)
{
path = findPath(bm1, currentPoint);
xorPath(bm1, path);
if (path.area > turdsize)
{
pathlist.Add(path);
}
weiter = findNext(bm1, currentPoint, ref currentPoint);
}
return(path);
}
static bool majority(Bitmap_p bm1, int x, int y)
{
int i;
int a;
int ct;
for (i = 2; i < 5; i++)
{
ct = 0;
for (a = -i + 1; a <= i - 1; a++)
{
ct += bm1.at(x + a, y + i - 1) ? 1 : -1;
ct += bm1.at(x + i - 1, y + a - 1) ? 1 : -1;
ct += bm1.at(x + a - 1, y - i) ? 1 : -1;
ct += bm1.at(x - i, y + a) ? 1 : -1;
}
if (ct > 0)
{
return(true);
}
else if (ct < 0)
{
return(false);
}
}
return(false);
}
/// <summary>
/// Searches a x and a y such that source[x,y] = 1 and source[x+1,y] 0.
/// If this not exists, false will be returned else the result is true.
///
/// </summary>
/// <param name="source">Is a Binary Matrix, which is produced by <see cref="BitMapToBinary"/>
/// <param name="x">x index in the source Matrix</param>
/// <param name="y">y index in the source Matrix</param>
static bool findNext(Bitmap_p bm1, Point point, ref Point result)
{
int i = bm1.w * point.Y + point.X;
while ((i < bm1.size) && (bm1.data[i] != 1))
{
i++;
}
if (i >= bm1.size)
{
return(false);
}
result = bm1.index(i);
return(true);
}
static void xorPath(Bitmap_p bm1, Path path)
{
int y1 = path.pt[0].Y,
len = path.len,
x, y, maxX, minY, i, j;
for (i = 1; i < len; i++)
{
x = path.pt[i].X;
y = path.pt[i].Y;
if (y != y1)
{
minY = y1 < y ? y1 : y;
maxX = path.maxX;
for (j = x; j < maxX; j++)
{
bm1.flip(j, minY);
}
y1 = y;
}
}
}
void Clear()
{
bm = null;
pathlist.Clear();
}
/// <summary>
/// Compute a path in the binary matrix.
/// Start path at the point (x0,x1), which must be an upper left corner
/// of the path. Also compute the area enclosed by the path. Return a
/// new path_t object, or NULL on error (note that a legitimate path
/// cannot have length 0).
/// </summary>
/// <param name="Matrix">Binary Matrix</param>
/// <returns></returns>
/// <param name="x">x index in the source Matrix</param>
/// <param name="y">y index in the source Matrix</param>
Path findPath(Bitmap_p bm1, Point point)
{
Path path = new Path();
int x = point.X;
int y = point.Y;
int dirx = 0;
int diry = 1;
int tmp = -1;
path.sign = bm.at(point.X, point.Y) ? "+" : "-";
while (true)
{
path.pt.Add(new Point(x, y));
if (x > path.maxX)
{
path.maxX = x;
}
if (x < path.minX)
{
path.minX = x;
}
if (y > path.maxY)
{
path.maxY = y;
}
if (y < path.minY)
{
path.minY = y;
}
path.len++;
x += dirx;
y += diry;
path.area -= x * diry;
if (x == point.X && y == point.Y)
{
break;
}
bool l = bm1.at(x + (dirx + diry - 1) / 2, y + (diry - dirx - 1) / 2);
bool r = bm1.at(x + (dirx - diry - 1) / 2, y + (diry + dirx - 1) / 2);
if (r && !l)
{
if ((turnpolicy == TurnPolicy.right) ||
(((turnpolicy == TurnPolicy.black) && (path.sign == "+"))) ||
(((turnpolicy == TurnPolicy.white) && (path.sign == "-"))) ||
(((turnpolicy == TurnPolicy.majority) && (majority(bm1, x, y)))) ||
((turnpolicy == TurnPolicy.minority && !majority(bm1, x, y))))
{
tmp = dirx;
dirx = -diry;
diry = tmp;
}
else
{
tmp = dirx;
dirx = diry;
diry = -tmp;
}
}
else if (r)
{
tmp = dirx;
dirx = -diry;
diry = tmp;
}
else if (!l)
{
tmp = dirx;
dirx = diry;
diry = -tmp;
}
}
return(path);
}
