public static BitmapSource SubSampleSmooth(BitmapSource bmp, int fac)
{
BitmapSource retVal = null;
int iWidth = (int)bmp.PixelWidth;
int iHeight = (int)bmp.PixelHeight;
int factor = fac;
int tWidth = iWidth / factor;
int tHeight = iHeight / factor;
int bpp = ((bmp.Format.BitsPerPixel + 7) / 8);
int iStride = iWidth * bpp;
int tStride = iStride / factor;
int dpi = 96;
byte[] imgBuffer = WpfImgUtilsEncoding.GetEncodedImageData(bmp);
byte[] thumbnailBuffer = new byte[tWidth * tHeight * bpp];
WriteableBitmap bs = new WriteableBitmap(iWidth, iHeight, dpi, dpi, bmp.Format, null);
bs.WritePixels(new Int32Rect(0, 0, iWidth, iHeight),
imgBuffer, iWidth * bpp, 0, 0);
//bs = WpfImgUtilsTransform.Resize(bmp, bmp.PixelWidth / factor, bmp.PixelHeight / factor, Interpolation.Bilinear);
//retVal = bs;
retVal = new TransformedBitmap(bs, new ScaleTransform(1.0 / factor, 1.0 / factor));
bs.Freeze();
return(retVal);
}
internal static WriteableBitmap Resize(BitmapSource bmp, int width, int height, Interpolation interpolation)
{
// Init vars
Int32[] ps = WpfImgUtilsEncoding.GetEncodedImageDataInt(bmp);
int ws = bmp.PixelWidth;
int hs = bmp.PixelHeight;
WriteableBitmap result = new WriteableBitmap(width, height, 96, 96, bmp.Format, null);
Int32[] pd = WpfImgUtilsEncoding.GetEncodedImageDataInt(result);
float xs = (float)ws / width;
float ys = (float)hs / height;
float fracx, fracy, ifracx, ifracy, sx, sy, l0, l1;
int c, x0, x1, y0, y1;
byte c1a, c1r, c1g, c1b, c2a, c2r, c2g, c2b, c3a, c3r, c3g, c3b, c4a, c4r, c4g, c4b;
byte a = 0, r = 0, g = 0, b = 0;
// Nearest Neighbor
if (interpolation == Interpolation.NearestNeighbor)
{
int srcIdx = 0;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
sx = x * xs;
sy = y * ys;
x0 = (int)sx;
y0 = (int)sy;
pd[srcIdx++] = ps[y0 * ws + x0];
}
}
}
// Bilinear
else if (interpolation == Interpolation.Bilinear)
{
int srcIdx = 0;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
sx = x * xs;
sy = y * ys;
x0 = (int)sx;
y0 = (int)sy;
// Calculate coordinates of the 4 interpolation points
fracx = sx - x0;
fracy = sy - y0;
ifracx = 1f - fracx;
ifracy = 1f - fracy;
x1 = x0 + 1;
if (x1 >= ws)
{
x1 = x0;
}
y1 = y0 + 1;
if (y1 >= hs)
{
y1 = y0;
}
// Read source color
c = ps[y0 * ws + x0];
c1a = (byte)(c >> 24);
c1r = (byte)(c >> 16);
c1g = (byte)(c >> 8);
c1b = (byte)(c);
c = ps[y0 * ws + x1];
c2a = (byte)(c >> 24);
c2r = (byte)(c >> 16);
c2g = (byte)(c >> 8);
c2b = (byte)(c);
c = ps[y1 * ws + x0];
c3a = (byte)(c >> 24);
c3r = (byte)(c >> 16);
c3g = (byte)(c >> 8);
c3b = (byte)(c);
c = ps[y1 * ws + x1];
c4a = (byte)(c >> 24);
c4r = (byte)(c >> 16);
c4g = (byte)(c >> 8);
c4b = (byte)(c);
// Calculate colors
// Alpha
l0 = ifracx * c1a + fracx * c2a;
l1 = ifracx * c3a + fracx * c4a;
a = (byte)(ifracy * l0 + fracy * l1);
if (a > 0)
{
// Red
l0 = ifracx * c1r * c1a + fracx * c2r * c2a;
l1 = ifracx * c3r * c3a + fracx * c4r * c4a;
r = (byte)((ifracy * l0 + fracy * l1) / a);
// Green
l0 = ifracx * c1g * c1a + fracx * c2g * c2a;
l1 = ifracx * c3g * c3a + fracx * c4g * c4a;
g = (byte)((ifracy * l0 + fracy * l1) / a);
// Blue
l0 = ifracx * c1b * c1a + fracx * c2b * c2a;
l1 = ifracx * c3b * c3a + fracx * c4b * c4a;
b = (byte)((ifracy * l0 + fracy * l1) / a);
}
// Write destination
pd[srcIdx++] = (a << 24) | (r << 16) | (g << 8) | b;
}
}
}
result.WritePixels(new Int32Rect(0, 0, result.PixelWidth, result.PixelHeight),
pd, result.PixelWidth * result.Format.BitsPerPixel / 8, 0, 0);
return(result);
}
public static BitmapSource SubSample(BitmapSource bmp, int fac)
{
BitmapSource retVal = null;
int iWidth = (int)bmp.PixelWidth;
int iHeight = (int)bmp.PixelHeight;
int factor = fac;
int tWidth = iWidth / factor;
int tHeight = iHeight / factor;
int bpp = ((bmp.Format.BitsPerPixel + 7) / 8);
int iStride = iWidth * bpp;
int tStride = iStride / factor;
int dpi = 96;
byte[] imgBuffer = WpfImgUtilsEncoding.GetEncodedImageData(bmp);
byte[] thumbnailBuffer = new byte[tWidth * tHeight * bpp];
int imgBufferOff = 0, thumbnailBufferOff = 0;
//subsample image (same code as RSA)
for (int i = 0; i < tHeight; i++)
{
for (int j = 0; j < tWidth * bpp; j += bpp)
{
if (bpp > 0)
{
thumbnailBuffer[thumbnailBufferOff + j] = imgBuffer[imgBufferOff + j * factor];
if (bpp > 1)
{
thumbnailBuffer[thumbnailBufferOff + j + 1] = imgBuffer[imgBufferOff + j * factor + 1];
if (bpp > 2)
{
thumbnailBuffer[thumbnailBufferOff + j + 2] = imgBuffer[imgBufferOff + j * factor + 2];
if (bpp > 3)
{
thumbnailBuffer[thumbnailBufferOff + j + 3] = imgBuffer[imgBufferOff + j * factor + 3];
}
}
}
}
}
imgBufferOff += iWidth * factor * bpp;
thumbnailBufferOff += tWidth * bpp;
}
//for (int i = 0; i < tWidth; i++)
//{
// for (int j = 0; j < tHeight * bpp; j++)
// {
// int srcOff = imgBufferOff + j * factor * bpp;
// int dstOff = thumbnailBufferOff + j * bpp;
// if (srcOff + bpp < imgBuffer.Length && dstOff + bpp < thumbnailBuffer.Length)
// {
// Buffer.BlockCopy(imgBuffer, srcOff, thumbnailBuffer, dstOff, bpp);
// }
// }
// imgBufferOff += iWidth * bpp * factor;
// thumbnailBufferOff += tWidth * bpp;
//}
WriteableBitmap bs = new WriteableBitmap(tWidth, tHeight, dpi, dpi, bmp.Format, null);
bs.WritePixels(new Int32Rect(0, 0, tWidth, tHeight),
thumbnailBuffer, tWidth * bpp, 0, 0);
bs.Freeze();
retVal = bs;
return(retVal);
}
