public static List <Point> Adapt(Bitmap bitmap, ThresholdParams param, /* int step = 4, int size = 5,*/ double threshold = 0.1)
{
var startTime = DateTime.Now;
var newTarget = new Bitmap(bitmap.Width, bitmap.Height);
BitmapData bitmapData1 = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height),
System.Drawing.Imaging.ImageLockMode.ReadWrite, bitmap.PixelFormat);
byte[] bitmapData = new byte[bitmapData1.Stride * bitmapData1.Height];
System.Runtime.InteropServices.Marshal.Copy(bitmapData1.Scan0, bitmapData, 0, bitmapData.Length);
bitmap.UnlockBits(bitmapData1);
List <Point> points = new List <Point>();
for (int i = 0; i < bitmap.Size.Width; i++)
{
for (int j = 0; j < bitmap.Size.Height; j++)
{
if (AdaptThreshold(ref bitmapData, i, j, param, threshold, bitmap.Width, bitmap.Height))
{
points.Add(new Point(i, j));
}
}
}
Console.WriteLine("[Threshold] Elapsed time:" + (DateTime.Now - startTime).ToString());
return(points);
}
private static bool AdaptThreshold(
ref byte[] bitmap,
int x,
int y,
ThresholdParams param,
double threshold,
int width,
int height
)
{
var originalCoord = (y * width + x) * param.Step;
if (x - param.WidnowSize / 2 < 0 ||
x + param.WidnowSize / 2 > width - 1 ||
y - param.WidnowSize / 2 < 0 ||
y + param.WidnowSize / 2 > height - 1
)
{
var v = Color.FromArgb(
bitmap[originalCoord + 3],
bitmap[originalCoord + 2],
bitmap[originalCoord + 1],
bitmap[originalCoord]
).GetBrightness();
v = v >= threshold ? v : 0;
return(v == 1 ? true : false);
}
float max = float.MinValue;
float min = float.MaxValue;
float originalColor = 0;
for (int i = 0; i < param.WidnowSize; i++)
{
for (int j = 0; j < param.WidnowSize; j++)
{
var coord = ((y - param.WidnowSize / 2 + j) * width +
(x - param.WidnowSize / 2 + i)) * param.Step;
if (coord == originalCoord)
{
originalColor = Color.FromArgb(
bitmap[coord + 3],
bitmap[coord + 2],
bitmap[coord + 1],
bitmap[coord]
).GetBrightness();
}
var value = Color.FromArgb(
bitmap[coord + 3],
bitmap[coord + 2],
bitmap[coord + 1],
bitmap[coord]
).GetBrightness();
if (value > max)
{
max = value;
}
if (value < min)
{
min = value;
}
}
}
float mean = (max + min) / 2;
float val = originalColor - mean;
if (val < threshold)
{
val = 0;
}
return(val == 0 ? false : true);
}
