public static Bitmap Negative(Bitmap bmp)
{
Bitmap retBmp = new Bitmap(bmp.Width, bmp.Height);
using (var bl = new BitmapLocker(bmp))
using (var rbl = new BitmapLocker(retBmp))
{
unsafe
{
for (int y = 0; y < bmp.Height; y++)
{
for (int x = 0; x < bmp.Width; x++)
{
byte *oldPixel = bl.GetPixelPtr(x, y);
byte *newPixel = rbl.GetPixelPtr(x, y);
for (int i = 0; i < 3; i++)
{
newPixel[i] = (byte)(255 - oldPixel[i]);
}
newPixel[3] = 255;
}
}
}
}
return(retBmp);
}
public static Bitmap PowerLawTransform(double c, double gamma, Bitmap bmp)
{
Bitmap retBmp = new Bitmap(bmp.Width, bmp.Height);
using (var bl = new BitmapLocker(bmp))
using (var rbl = new BitmapLocker(retBmp))
{
unsafe
{
for (int y = 0; y < bmp.Height; y++)
{
for (int x = 0; x < bmp.Width; x++)
{
byte *oldPixel = bl.GetPixelPtr(x, y);
byte *newPixel = rbl.GetPixelPtr(x, y);
for (int i = 0; i < 3; i++)
{
double val = c * Math.Pow(oldPixel[i], gamma);
if (val < 0)
{
val = 0;
}
if (val > 255)
{
val = 255;
}
newPixel[i] = (byte)(Math.Round(val));
}
newPixel[3] = 255;
}
}
}
}
return(retBmp);
}
public static Bitmap Median(Bitmap bmp)
{
Bitmap retBmp = new Bitmap(bmp.Width, bmp.Height);
Dictionary <byte, long> Rcdf = new Dictionary <byte, long>(), Gcdf = new Dictionary <byte, long>(), Bcdf = new Dictionary <byte, long>();
using (var bl = new BitmapLocker(bmp))
using (var rbl = new BitmapLocker(retBmp)) {
unsafe {
for (int y = 0; y < bmp.Height; y++)
{
for (int x = 0; x < bmp.Width; x++)
{
List <Color> colors = new List <Color>();
List <int> A = new List <int>();
List <int> R = new List <int>();
List <int> G = new List <int>();
List <int> B = new List <int>();
for (int dy = -1; dy < 1; dy++)
{
if (y + dy < 0 || y + dy >= bmp.Height)
{
continue;
}
for (int dx = -1; dx < 1; dx++)
{
if (x + dx < 0 || x + dx >= bmp.Width)
{
continue;
}
Color color = bl.GetPixelColor(x + dx, y + dy);
colors.Add(color);
}
}
//colors = colors.Distinct().ToList();
colors.ForEach(c => {
A.Add(c.A);
R.Add(c.R);
G.Add(c.G);
B.Add(c.B);
});
A.Sort(); R.Sort(); G.Sort(); B.Sort();
int middle = (colors.Count - 1) / 2;
Color newColor = Color.FromArgb(A[middle], R[middle], G[middle], B[middle]);
int * ptr = rbl.GetPixelIntPtr(x, y);
* ptr = newColor.ToArgb();
}
}
}
}
return(retBmp);
}
public static Bitmap Mean(Bitmap bmp)
{
Bitmap retBmp = new Bitmap(bmp.Width, bmp.Height);
Dictionary <byte, long> Rcdf = new Dictionary <byte, long>(), Gcdf = new Dictionary <byte, long>(), Bcdf = new Dictionary <byte, long>();
using (var bl = new BitmapLocker(bmp))
using (var rbl = new BitmapLocker(retBmp)) {
unsafe {
for (int y = 0; y < bmp.Height; y++)
{
for (int x = 0; x < bmp.Width; x++)
{
List <int> A = new List <int>();
List <int> R = new List <int>();
List <int> G = new List <int>();
List <int> B = new List <int>();
for (int dy = -1; dy < 1; dy++)
{
if (y + dy < 0 || y + dy >= bmp.Height)
{
continue;
}
for (int dx = -1; dx < 1; dx++)
{
if (x + dx < 0 || x + dx >= bmp.Width)
{
continue;
}
Color color = bl.GetPixelColor(x + dx, y + dy);
A.Add(color.A);
R.Add(color.R);
G.Add(color.G);
B.Add(color.B);
}
}
Color newColor = Color.FromArgb((int)A.Average(), (int)R.Average(), (int)G.Average(), (int)B.Average());
*rbl.GetPixelIntPtr(x, y) = newColor.ToArgb();
}
}
}
}
return(retBmp);
}
public static Bitmap HistogramEqualization(Bitmap bmp)
{
Bitmap retBmp = new Bitmap(bmp.Width, bmp.Height);
Dictionary <byte, long> Rcdf = new Dictionary <byte, long>(), Gcdf = new Dictionary <byte, long>(), Bcdf = new Dictionary <byte, long>();
using (var bl = new BitmapLocker(bmp))
using (var rbl = new BitmapLocker(retBmp))
{
unsafe
{
for (int y = 0; y < bmp.Height; y++)
{
for (int x = 0; x < bmp.Width; x++)
{
Color c = bl.GetPixelColor(x, y);
if (!Rcdf.ContainsKey(c.R))
{
Rcdf.Add(c.R, 0);
}
Rcdf[c.R]++;
if (!Gcdf.ContainsKey(c.G))
{
Gcdf.Add(c.G, 0);
}
Gcdf[c.G]++;
if (!Bcdf.ContainsKey(c.B))
{
Bcdf.Add(c.B, 0);
}
Bcdf[c.B]++;
}
}
}
// actual cdf processing
long sumR, sumG, sumB;
sumB = sumG = sumR = 0;
for (int i = 0; i < 256; ++i)
{
byte bytei = (byte)i;
if (Rcdf.ContainsKey(bytei))
{
Rcdf[bytei] += sumR;
sumR = Rcdf[bytei];
}
if (Gcdf.ContainsKey(bytei))
{
Gcdf[bytei] += sumG;
sumG = Gcdf[bytei];
}
if (Bcdf.ContainsKey(bytei))
{
Bcdf[bytei] += sumB;
sumB = Bcdf[bytei];
}
}
// draw retBmp
long totalPixels = retBmp.Width * retBmp.Height;
long RcdfMin = Rcdf.Values.Min(), GcdfMin = Gcdf.Values.Min(), BcdfMin = Bcdf.Values.Min();
unsafe
{
for (int y = 0; y < retBmp.Height; y++)
{
for (int x = 0; x < retBmp.Width; x++)
{
Color oldColor = bl.GetPixelColor(x, y);
int * newColorIntPtr = rbl.GetPixelIntPtr(x, y);
int R, G, B;
R = (int)Math.Round((Rcdf[oldColor.R] - RcdfMin) * 255.0 / (totalPixels - RcdfMin));
G = (int)Math.Round((Gcdf[oldColor.G] - GcdfMin) * 255.0 / (totalPixels - GcdfMin));
B = (int)Math.Round((Bcdf[oldColor.B] - BcdfMin) * 255.0 / (totalPixels - BcdfMin));
Color newColor = Color.FromArgb(oldColor.A, R, G, B);
* newColorIntPtr = newColor.ToArgb();
}
}
}
}
return(retBmp);
}
