/// <summary>
/// Search region of mokkans in image
/// </summary>
public static unsafe Rectangle SearchMokkanRegion(Bitmap image, Rectangle rect)
{
Bitmap bin = Binarization.Threshold(image, rect, MkaDefine.THRESHOLD);
BitmapData bmd = bin.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.WriteOnly, bin.PixelFormat);
// calculate projection profiles
int wid = image.Width;
int hei = image.Height;
int stride = bmd.Stride;
int[] hProj = new int[wid];
int[] vProj = new int[hei];
int left = rect.Left;
int right = rect.Right;
int top = rect.Top;
int bottom = rect.Bottom;
// search vertical range
byte *ptr = (byte *)bmd.Scan0.ToPointer();
Histogram.VerHistB(ptr, bmd.Stride, rect, vProj);
SearchMokkanRegion(vProj, ref top, ref bottom);
// remove upper part
ptr = (byte *)bmd.Scan0.ToPointer();
for (int y = 0; y <= top; y++)
{
SystemTools.SetUnmanagedMemory(ptr, 255, wid);
ptr += wid;
}
// remove lower part
ptr = (byte *)bmd.Scan0.ToPointer() + (bottom - 1) * stride;
for (int y = 0; y < hei - bottom; y++)
{
SystemTools.SetUnmanagedMemory(ptr, 255, wid);
ptr += wid;
}
// search horizontal range
ptr = (byte *)bmd.Scan0.ToPointer();
Histogram.HorHistB(ptr, bmd.Stride, rect, hProj);
SearchMokkanRegion(hProj, ref left, ref right);
bin.UnlockBits(bmd);
bin.Dispose();
return(Rectangle.FromLTRB(left, top, right, bottom));
}
/// <summary>
/// Color filtering in YCbCr color space.
/// </summary>
public static unsafe Bitmap YCbCrFilter(Bitmap image, Rectangle rect, DoubleRange Y, DoubleRange Cb, DoubleRange Cr)
{
Bitmap dest = new Bitmap(image.Width, image.Height, PixelFormat.Format8bppIndexed);
BitmapData source = image.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.ReadWrite, image.PixelFormat);
BitmapData destination = dest.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.ReadWrite, dest.PixelFormat);
int startX = rect.Left;
int startY = rect.Top;
int stopX = rect.Right;
int stopY = rect.Bottom;
// get pixel size
int pixelSize = (image.PixelFormat == PixelFormat.Format24bppRgb) ? 3 : 4;
int srcOffset = source.Stride - rect.Width * pixelSize;
int dstOffset = destination.Stride - rect.Width;
RGB rgb = new RGB();
YCbCr ycbcr = new YCbCr();
// do the job
byte *src = (byte *)source.Scan0 + startY * source.Stride + startX * pixelSize;
byte *dst = (byte *)destination.Scan0 + startY * destination.Stride + startX;
// for each row
for (int y = startY; y < stopY; y++)
{
// for each pixel
for (int x = startX; x < stopX; x++, src += pixelSize, dst++)
{
rgb.Red = src[RGB.R];
rgb.Green = src[RGB.G];
rgb.Blue = src[RGB.B];
// convert to YCbCr
ycbcr = YCbCr.FromRGB(rgb);
// check YCbCr values
if (Y.IsInside(ycbcr.Y) & Cb.IsInside(ycbcr.Cb) && Cr.IsInside(ycbcr.Cr))
{
*dst = 0;
}
else
{
*dst = 255;
}
}
src += srcOffset;
dst += dstOffset;
}
int width = image.Width;
int height = image.Height;
int stride = destination.Stride;
// remove upper part
for (int y = 0; y < startY; y++)
{
dst = (byte *)destination.Scan0.ToPointer() + y * stride;
SystemTools.SetUnmanagedMemory(dst, 255, stride);
}
// remove lower part
for (int y = stopY; y < height; y++)
{
dst = (byte *)destination.Scan0.ToPointer() + y * stride;
SystemTools.SetUnmanagedMemory(dst, 255, stride);
}
for (int y = startY; y < stopY; y++)
{
// remove left part
dst = (byte *)destination.Scan0.ToPointer() + y * stride;
SystemTools.SetUnmanagedMemory(dst, 255, startX);
// remove right part
dst += stopX;
SystemTools.SetUnmanagedMemory(dst, 255, stride - stopX);
}
image.UnlockBits(source);
dest.UnlockBits(destination);
return(dest);
}
