// Calculating from fastBitmap depending if image is grayscale
public Histogram(FastBitmap bmp, bool isGrayscale)
{
if (isGrayscale)
{
HistogramTable = new int[256];
for (int i = 0; i < bmp.Size.Width; ++i)
{
for (int j = 0; j < bmp.Size.Height; ++j)
{
HistogramTable[bmp[i, j].R]++;
Total++;
}
}
Max = HistogramTable.Max();
Average = HistogramTable.Average();
}
else
{
// Calculating RGB histogram values
HistogramTable = new int[256];
HistogramTableRed = new int[256];
HistogramTableGreen = new int[256];
HistogramTableBlue = new int[256];
for (int i = 0; i < bmp.Size.Width; ++i)
{
for (int j = 0; j < bmp.Size.Height; ++j)
{
HistogramTable[bmp[i, j].R]++;
HistogramTableRed[bmp[i, j].R]++;
HistogramTableGreen[bmp[i, j].G]++;
HistogramTableBlue[bmp[i, j].B]++;
Total++;
}
}
Max = HistogramTable.Max();
Average = HistogramTable.Average();
}
}
// Point operations
public static FastBitmap Operation(FastBitmap bmp1, FastBitmap bmp2, Operations op)
{
// Combining two images
FastBitmap bmp = new FastBitmap(Math.Max(bmp1.Width, bmp2.Width), Math.Max(bmp1.Height, bmp2.Height));
for (int i = 0; i < bmp.Size.Width; ++i)
{
for (int j = 0; j < bmp.Size.Height; ++j)
{
Color c1;
Color c2;
if (isPixelValid(i, j, bmp1.Width, bmp1.Height))
{
c1 = bmp1[i, j];
}
else
{
c1 = Color.Black;
}
if (isPixelValid(i, j, bmp2.Width, bmp2.Height))
{
c2 = bmp2[i, j];
}
else
{
c2 = Color.Black;
}
// Switching through operations and performing last one
switch (op)
{
case Operations.Add:
bmp[i, j] = Color.FromArgb(255, Math.Min(255, c1.R + c2.R), Math.Min(255, c1.G + c2.G), Math.Min(255, c1.B + c2.B));
break;
case Operations.Subtract:
bmp[i, j] = Color.FromArgb(255, Math.Max(0, c1.R - c2.R), Math.Max(0, c1.G - c2.G), Math.Max(0, c1.B - c2.B));
break;
case Operations.Multiply:
bmp[i, j] = Color.FromArgb(255, Math.Min(255, c1.R * c2.R), Math.Min(255, c1.G * c2.G), Math.Min(255, c1.B * c2.B));
break;
case Operations.Divide:
bmp[i, j] = Color.FromArgb(255, c1.R / Math.Max((byte)1, c2.R), c1.G / Math.Max((byte)1, c2.G), c1.B / Math.Max((byte)1, c2.B));
break;
case Operations.Difference:
bmp[i, j] = Color.FromArgb(255, Math.Abs(c1.R - c2.R), Math.Abs(c1.G - c2.G), Math.Abs(c1.B - c2.B));
break;
case Operations.AND:
bmp[i, j] = Color.FromArgb(255, Math.Max(0, Math.Min(255, c1.R & c2.R)), Math.Max(0, Math.Min(255, c1.G & c2.G)), Math.Max(0, Math.Min(255, c1.B & c2.B)));
break;
case Operations.OR:
bmp[i, j] = Color.FromArgb(255, Math.Max(0, Math.Min(255, c1.R | c2.R)), Math.Max(0, Math.Min(255, c1.G | c2.G)), Math.Max(0, Math.Min(255, c1.B | c2.B)));
break;
case Operations.XOR:
bmp[i, j] = Color.FromArgb(255, Math.Max(0, Math.Min(255, c1.R ^ c2.R)), Math.Max(0, Math.Min(255, c1.G ^ c2.G)), Math.Max(0, Math.Min(255, c1.B ^ c2.B)));
break;
}
}
}
return(bmp);
}
// Thinning (Skeletonization) method
public static void Thinning(FastBitmap bmp)
{
// Init edge operators
int[] dx = { 0, 1, 1, 1, 0, -1, -1, -1 };
int[] dy = { 1, 1, 0, -1, -1, -1, 0, 1 };
bool[,] img = new bool[bmp.Width, bmp.Height];
int W = bmp.Width;
int H = bmp.Height;
for (int i = 0; i < bmp.Width; ++i)
{
for (int j = 0; j < bmp.Height; ++j)
{
img[i, j] = bmp[i, j].B < 128;
}
}
bool pass = false;
LinkedList <Point> list;
do
{
pass = !pass;
list = new LinkedList <Point>();
for (int x = 1; x < W - 1; ++x)
{
for (int y = 1; y < H - 1; ++y)
{
if (img[x, y])
{
int cnt = 0;
int hm = 0;
bool prev = img[x - 1, y + 1];
for (int i = 0; i < 8; ++i)
{
bool cur = img[x + dx[i], y + dy[i]];
hm += cur ? 1 : 0;
if (prev && !cur)
{
++cnt;
}
prev = cur;
}
if (hm > 1 && hm < 7 && cnt == 1)
{
if (pass && (!img[x + 1, y] || !img[x, y + 1] || !img[x, y - 1] && !img[x - 1, y]))
{
list.AddLast(new Point(x, y));
}
if (!pass && (!img[x - 1, y] || !img[x, y - 1] || !img[x, y + 1] && !img[x + 1, y]))
{
list.AddLast(new Point(x, y));
}
}
}
}
}
foreach (Point p in list)
{
img[p.X, p.Y] = false;
}
} while (list.Count != 0);
for (int x = 0; x < W; ++x)
{
for (int y = 0; y < H; ++y)
{
bmp[x, y] = img[x, y] ? Color.Black : Color.White;
}
}
}
