/// <summary>
/// Gets a BitmapContext within which to perform nested IO operations on the bitmap
/// </summary>
/// <remarks>For WPF the BitmapContext will lock the bitmap. Call Dispose on the context to unlock</remarks>
/// <param name="bmp"></param>
/// <returns></returns>
public static BitmapContext GetBitmapContext(this BitmapBuffer bmp)
{
return(new BitmapContext(bmp));
}
/// <summary>
/// Draws a colored line by connecting two points using the Bresenham algorithm.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="x1">The x-coordinate of the start point.</param>
/// <param name="y1">The y-coordinate of the start point.</param>
/// <param name="x2">The x-coordinate of the end point.</param>
/// <param name="y2">The y-coordinate of the end point.</param>
/// <param name="color">The color for the line.</param>
/// <param name="clipRect">The region in the image to restrict drawing to.</param>
public static unsafe void DrawLineBresenham(this BitmapBuffer bmp, int x1, int y1, int x2, int y2, int color, RectD?clipRect = null)
{
using (BitmapContext context = bmp.GetBitmapContext())
{
// Use refs for faster access (really important!) speeds up a lot!
int w = context.Width;
int h = context.Height;
int *pixels = context.Pixels._inf32Buffer;
// Get clip coordinates
int clipX1 = 0;
int clipX2 = w;
int clipY1 = 0;
int clipY2 = h;
if (clipRect.HasValue)
{
var c = clipRect.Value;
clipX1 = (int)c.X;
clipX2 = (int)(c.X + c.Width);
clipY1 = (int)c.Y;
clipY2 = (int)(c.Y + c.Height);
}
// Distance start and end point
int dx = x2 - x1;
int dy = y2 - y1;
// Determine sign for direction x
int incx = 0;
if (dx < 0)
{
dx = -dx;
incx = -1;
}
else if (dx > 0)
{
incx = 1;
}
// Determine sign for direction y
int incy = 0;
if (dy < 0)
{
dy = -dy;
incy = -1;
}
else if (dy > 0)
{
incy = 1;
}
// Which gradient is larger
int pdx, pdy, odx, ody, es, el;
if (dx > dy)
{
pdx = incx;
pdy = 0;
odx = incx;
ody = incy;
es = dy;
el = dx;
}
else
{
pdx = 0;
pdy = incy;
odx = incx;
ody = incy;
es = dx;
el = dy;
}
// Init start
int x = x1;
int y = y1;
int error = el >> 1;
if (y < clipY2 && y >= clipY1 && x < clipX2 && x >= clipX1)
{
pixels[y * w + x] = color;
}
// Walk the line!
for (int i = 0; i < el; i++)
{
// Update error term
error -= es;
// Decide which coord to use
if (error < 0)
{
error += el;
x += odx;
y += ody;
}
else
{
x += pdx;
y += pdy;
}
// Set pixel
if (y < clipY2 && y >= clipY1 && x < clipX2 && x >= clipX1)
{
pixels[y * w + x] = color;
}
}
}
}
private const byte TOP = 8; // 1000
/// <summary>
/// Draws a line using a pen / stamp for the line
/// </summary>
/// <param name="bmp">The WriteableBitmap containing the pixels as int RGBA value.</param>
/// <param name="w">The width of one scanline in the pixels array.</param>
/// <param name="h">The height of the bitmap.</param>
/// <param name="x1">The x-coordinate of the start point.</param>
/// <param name="y1">The y-coordinate of the start point.</param>
/// <param name="x2">The x-coordinate of the end point.</param>
/// <param name="y2">The y-coordinate of the end point.</param>
/// <param name="penBmp">The pen bitmap.</param>
public static void DrawLinePenned(this BitmapBuffer bmp, int x1, int y1, int x2, int y2, BitmapBuffer penBmp, RectD?clipRect = null)
{
using (BitmapContext context = bmp.GetBitmapContext())
using (BitmapContext penContext = penBmp.GetBitmapContext(ReadWriteMode.ReadOnly))
{
DrawLinePenned(context, bmp.PixelWidth, bmp.PixelHeight, x1, y1, x2, y2, penContext, clipRect);
}
}
/// <summary>
/// Draws a cubic Beziér spline defined by start, end and two control points.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="x1">The x-coordinate of the start point.</param>
/// <param name="y1">The y-coordinate of the start point.</param>
/// <param name="cx1">The x-coordinate of the 1st control point.</param>
/// <param name="cy1">The y-coordinate of the 1st control point.</param>
/// <param name="cx2">The x-coordinate of the 2nd control point.</param>
/// <param name="cy2">The y-coordinate of the 2nd control point.</param>
/// <param name="x2">The x-coordinate of the end point.</param>
/// <param name="y2">The y-coordinate of the end point.</param>
/// <param name="color">The color.</param>
public static void DrawBezier(this BitmapBuffer bmp, int x1, int y1, int cx1, int cy1, int cx2, int cy2, int x2, int y2, ColorInt color)
{
bmp.DrawBezier(x1, y1, cx1, cy1, cx2, cy2, x2, y2, color.ToPreMultAlphaColor());
}
/// <summary>
/// Draws a colored line by connecting two points using the Bresenham algorithm.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="x1">The x-coordinate of the start point.</param>
/// <param name="y1">The y-coordinate of the start point.</param>
/// <param name="x2">The x-coordinate of the end point.</param>
/// <param name="y2">The y-coordinate of the end point.</param>
/// <param name="color">The color for the line.</param>
/// <param name="clipRect">The region in the image to restrict drawing to.</param>
public static void DrawLineBresenham(this BitmapBuffer bmp, int x1, int y1, int x2, int y2, ColorInt color, RectD?clipRect = null)
{
bmp.DrawLineBresenham(x1, y1, x2, y2, color.ToPreMultAlphaColor(), clipRect);
}
/// <summary>
/// Rotates the bitmap in 90° steps clockwise and returns a new rotated WriteableBitmap.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="angle">The angle in degrees the bitmap should be rotated in 90° steps clockwise.</param>
/// <returns>A new WriteableBitmap that is a rotated version of the input.</returns>
public static BitmapBuffer Rotate(this BitmapBuffer bmp, FastRotateAngle angle)
{
using (BitmapContext context = bmp.GetBitmapContext(ReadWriteMode.ReadOnly))
{
// Use refs for faster access (really important!) speeds up a lot!
int w = context.Width;
int h = context.Height;
int[] p = context.Pixels;
int i = 0;
switch (angle)
{
default:
{
return(bmp.Clone());
}
case FastRotateAngle.Rotate90:
{
var result = BitmapBufferFactory.New(h, w);
using (BitmapContext destContext = result.GetBitmapContext())
{
var rp = destContext.Pixels;
for (int x = 0; x < w; x++)
{
for (int y = h - 1; y >= 0; y--)
{
int srcInd = y * w + x;
rp[i] = p[srcInd];
i++;
}
}
}
return(result);
}
case FastRotateAngle.Rotate180:
{
var result = BitmapBufferFactory.New(w, h);
using (BitmapContext destContext = result.GetBitmapContext())
{
var rp = destContext.Pixels;
for (int y = h - 1; y >= 0; y--)
{
for (int x = w - 1; x >= 0; x--)
{
int srcInd = y * w + x;
rp[i] = p[srcInd];
i++;
}
}
}
return(result);
}
case FastRotateAngle.Rotate270:
{
var result = BitmapBufferFactory.New(h, w);
using (BitmapContext destContext = result.GetBitmapContext())
{
int[] rp = destContext.Pixels;
for (int x = w - 1; x >= 0; x--)
{
for (int y = 0; y < h; y++)
{
int srcInd = y * w + x;
rp[i] = p[srcInd];
i++;
}
}
}
return(result);
}
}
}
}
/// <summary>
/// Draws a closed Cardinal spline (cubic) defined by a point collection.
/// The cardinal spline passes through each point in the collection.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="points">The points for the curve in x and y pairs, therefore the array is interpreted as (x1, y1, x2, y2, x3, y3, x4, y4, x1, x2 ..., xn, yn).</param>
/// <param name="tension">The tension of the curve defines the shape. Usually between 0 and 1. 0 would be a straight line.</param>
/// <param name="color">The color for the spline.</param>
public static void DrawCurveClosed(this BitmapBuffer bmp, int[] points, float tension, ColorInt color)
{
bmp.DrawCurveClosed(points, tension, color.ToPreMultAlphaColor());
}
/// <summary>
/// Copies all the Pixels from the WriteableBitmap into a ARGB byte array.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <returns>The color buffer as byte ARGB values.</returns>
public static byte[] ToByteArray(this BitmapBuffer bmp)
{
return(bmp.ToByteArray(0, -1));
}
/// <summary>
/// Copies color information from an ARGB byte array into this WriteableBitmap.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="count">The number of bytes to copy from the buffer.</param>
/// <param name="buffer">The color buffer as byte ARGB values.</param>
/// <returns>The WriteableBitmap that was passed as parameter.</returns>
public static BitmapBuffer FromByteArray(this BitmapBuffer bmp, byte[] buffer, int count)
{
return(bmp.FromByteArray(buffer, 0, count));
}
/// <summary>
/// Writes the WriteableBitmap as a TGA image to a stream.
/// Used with permission from Nokola: http://nokola.com/blog/post/2010/01/21/Quick-and-Dirty-Output-of-WriteableBitmap-as-TGA-Image.aspx
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="destination">The destination stream.</param>
public static void WriteTga(this BitmapBuffer bmp, Stream destination)
{
using (BitmapContext context = bmp.GetBitmapContext(ReadWriteMode.ReadOnly))
{
int width = context.Width;
int height = context.Height;
int[] pixels = context.Pixels;
byte[] data = new byte[context.Length * ARGB_SIZE];
// Copy bitmap data as BGRA
int offsetSource = 0;
int width4 = width << 2;
int width8 = width << 3;
int offsetDest = (height - 1) * width4;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
// Account for pre-multiplied alpha
int c = pixels[offsetSource];
byte a = (byte)(c >> 24);
// Prevent division by zero
int ai = a;
if (ai == 0)
{
ai = 1;
}
// Scale inverse alpha to use cheap integer mul bit shift
ai = ((255 << 8) / ai);
data[offsetDest + 3] = (byte)a; // A
data[offsetDest + 2] = (byte)((((c >> 16) & 0xFF) * ai) >> 8); // R
data[offsetDest + 1] = (byte)((((c >> 8) & 0xFF) * ai) >> 8); // G
data[offsetDest] = (byte)((((c & 0xFF) * ai) >> 8)); // B
offsetSource++;
offsetDest += ARGB_SIZE;
}
offsetDest -= width8;
}
// Create header
var header = new byte[]
{
0, // ID length
0, // no color map
2, // uncompressed, true color
0, 0, 0, 0,
0,
0, 0, 0, 0, // x and y origin
(byte)(width & 0x00FF),
(byte)((width & 0xFF00) >> 8),
(byte)(height & 0x00FF),
(byte)((height & 0xFF00) >> 8),
32, // 32 bit bitmap
0
};
// Write header and data
using (var writer = new BinaryWriter(destination))
{
writer.Write(header);
writer.Write(data);
}
}
}
/// <summary>
/// Copies the Pixels from the WriteableBitmap into a ARGB byte array.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="count">The number of pixels to copy.</param>
/// <returns>The color buffer as byte ARGB values.</returns>
public static byte[] ToByteArray(this BitmapBuffer bmp, int count)
{
return(bmp.ToByteArray(0, count));
}
/// <summary>
/// Copies all the color information from an ARGB byte array into this WriteableBitmap.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="buffer">The color buffer as byte ARGB values.</param>
/// <returns>The WriteableBitmap that was passed as parameter.</returns>
public static BitmapBuffer FromByteArray(this BitmapBuffer bmp, byte[] buffer)
{
return(bmp.FromByteArray(buffer, 0, buffer.Length));
}
/// <summary>
/// Creates a new filtered WriteableBitmap.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="kernel">The kernel used for convolution.</param>
/// <param name="kernelFactorSum">The factor used for the kernel summing.</param>
/// <param name="kernelOffsetSum">The offset used for the kernel summing.</param>
/// <returns>A new WriteableBitmap that is a filtered version of the input.</returns>
public static unsafe BitmapBuffer Convolute(this BitmapBuffer bmp, int[,] kernel, int kernelFactorSum, int kernelOffsetSum)
{
int kh = kernel.GetUpperBound(0) + 1;
int kw = kernel.GetUpperBound(1) + 1;
if ((kw & 1) == 0)
{
throw new System.InvalidOperationException("Kernel width must be odd!");
}
if ((kh & 1) == 0)
{
throw new System.InvalidOperationException("Kernel height must be odd!");
}
using (BitmapContext srcContext = bmp.GetBitmapContext(ReadWriteMode.ReadOnly))
{
int w = srcContext.Width;
int h = srcContext.Height;
BitmapBuffer result = BitmapBufferFactory.New(w, h);
using (BitmapContext resultContext = result.GetBitmapContext())
{
int *pixels = srcContext.Pixels._inf32Buffer;
int *resultPixels = resultContext.Pixels._inf32Buffer;
int index = 0;
int kwh = kw >> 1;
int khh = kh >> 1;
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
int a = 0;
int r = 0;
int g = 0;
int b = 0;
for (int kx = -kwh; kx <= kwh; kx++)
{
int px = kx + x;
// Repeat pixels at borders
if (px < 0)
{
px = 0;
}
else if (px >= w)
{
px = w - 1;
}
for (int ky = -khh; ky <= khh; ky++)
{
int py = ky + y;
// Repeat pixels at borders
if (py < 0)
{
py = 0;
}
else if (py >= h)
{
py = h - 1;
}
int col = pixels[py * w + px];
int k = kernel[ky + kwh, kx + khh];
a += ((col >> 24) & 0xff) * k;
r += ((col >> 16) & 0xff) * k;
g += ((col >> 8) & 0xff) * k;
b += ((col) & 0xff) * k;
}
}
int ta = ((a / kernelFactorSum) + kernelOffsetSum);
int tr = ((r / kernelFactorSum) + kernelOffsetSum);
int tg = ((g / kernelFactorSum) + kernelOffsetSum);
int tb = ((b / kernelFactorSum) + kernelOffsetSum);
// Clamp to byte boundaries
byte ba = (byte)((ta > 255) ? 255 : ((ta < 0) ? 0 : ta));
byte br = (byte)((tr > 255) ? 255 : ((tr < 0) ? 0 : tr));
byte bg = (byte)((tg > 255) ? 255 : ((tg < 0) ? 0 : tg));
byte bb = (byte)((tb > 255) ? 255 : ((tb < 0) ? 0 : tb));
resultPixels[index++] = (ba << 24) | (br << 16) | (bg << 8) | (bb);
}
}
return(result);
}
}
}
/// <summary>
/// Rotates the bitmap in any degree returns a new rotated WriteableBitmap.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="angle">Arbitrary angle in 360 Degrees (positive = clockwise).</param>
/// <param name="crop">if true: keep the size, false: adjust canvas to new size</param>
/// <returns>A new WriteableBitmap that is a rotated version of the input.</returns>
public static BitmapBuffer RotateFree(this BitmapBuffer bmp, double angle, bool crop = true)
{
// rotating clockwise, so it's negative relative to Cartesian quadrants
double cnAngle = -1.0 * (Math.PI / 180) * angle;
// general iterators
int i, j;
// calculated indices in Cartesian coordinates
int x, y;
double fDistance, fPolarAngle;
// for use in neighboring indices in Cartesian coordinates
int iFloorX, iCeilingX, iFloorY, iCeilingY;
// calculated indices in Cartesian coordinates with trailing decimals
double fTrueX, fTrueY;
// for interpolation
double fDeltaX, fDeltaY;
// interpolated "top" pixels
double fTopRed, fTopGreen, fTopBlue, fTopAlpha;
// interpolated "bottom" pixels
double fBottomRed, fBottomGreen, fBottomBlue, fBottomAlpha;
// final interpolated color components
int iRed, iGreen, iBlue, iAlpha;
int iCentreX, iCentreY;
int iDestCentreX, iDestCentreY;
int iWidth, iHeight, newWidth, newHeight;
using (var bmpContext = bmp.GetBitmapContext(ReadWriteMode.ReadOnly))
{
iWidth = bmpContext.Width;
iHeight = bmpContext.Height;
if (crop)
{
newWidth = iWidth;
newHeight = iHeight;
}
else
{
double rad = angle / (180 / Math.PI);
newWidth = (int)Math.Ceiling(Math.Abs(Math.Sin(rad) * iHeight) + Math.Abs(Math.Cos(rad) * iWidth));
newHeight = (int)Math.Ceiling(Math.Abs(Math.Sin(rad) * iWidth) + Math.Abs(Math.Cos(rad) * iHeight));
}
iCentreX = iWidth / 2;
iCentreY = iHeight / 2;
iDestCentreX = newWidth / 2;
iDestCentreY = newHeight / 2;
BitmapBuffer bmBilinearInterpolation = BitmapBufferFactory.New(newWidth, newHeight);
using (BitmapContext bilinearContext = bmBilinearInterpolation.GetBitmapContext())
{
int[] newp = bilinearContext.Pixels;
int[] oldp = bmpContext.Pixels;
int oldw = bmpContext.Width;
// assigning pixels of destination image from source image
// with bilinear interpolation
for (i = 0; i < newHeight; ++i)
{
for (j = 0; j < newWidth; ++j)
{
// convert raster to Cartesian
x = j - iDestCentreX;
y = iDestCentreY - i;
// convert Cartesian to polar
fDistance = Math.Sqrt(x * x + y * y);
if (x == 0)
{
if (y == 0)
{
// center of image, no rotation needed
newp[i * newWidth + j] = oldp[iCentreY * oldw + iCentreX];
continue;
}
if (y < 0)
{
fPolarAngle = 1.5 * Math.PI;
}
else
{
fPolarAngle = 0.5 * Math.PI;
}
}
else
{
fPolarAngle = Math.Atan2(y, x);
}
// the crucial rotation part
// "reverse" rotate, so minus instead of plus
fPolarAngle -= cnAngle;
// convert polar to Cartesian
fTrueX = fDistance * Math.Cos(fPolarAngle);
fTrueY = fDistance * Math.Sin(fPolarAngle);
// convert Cartesian to raster
fTrueX = fTrueX + iCentreX;
fTrueY = iCentreY - fTrueY;
iFloorX = (int)(Math.Floor(fTrueX));
iFloorY = (int)(Math.Floor(fTrueY));
iCeilingX = (int)(Math.Ceiling(fTrueX));
iCeilingY = (int)(Math.Ceiling(fTrueY));
// check bounds
if (iFloorX < 0 || iCeilingX < 0 || iFloorX >= iWidth || iCeilingX >= iWidth || iFloorY < 0 ||
iCeilingY < 0 || iFloorY >= iHeight || iCeilingY >= iHeight)
{
continue;
}
fDeltaX = fTrueX - iFloorX;
fDeltaY = fTrueY - iFloorY;
int clrTopLeft = oldp[iFloorY * oldw + iFloorX];
int clrTopRight = oldp[iFloorY * oldw + iCeilingX];
int clrBottomLeft = oldp[iCeilingY * oldw + iFloorX];
int clrBottomRight = oldp[iCeilingY * oldw + iCeilingX];
fTopAlpha = (1 - fDeltaX) * ((clrTopLeft >> 24) & 0xFF) + fDeltaX * ((clrTopRight >> 24) & 0xFF);
fTopRed = (1 - fDeltaX) * ((clrTopLeft >> 16) & 0xFF) + fDeltaX * ((clrTopRight >> 16) & 0xFF);
fTopGreen = (1 - fDeltaX) * ((clrTopLeft >> 8) & 0xFF) + fDeltaX * ((clrTopRight >> 8) & 0xFF);
fTopBlue = (1 - fDeltaX) * (clrTopLeft & 0xFF) + fDeltaX * (clrTopRight & 0xFF);
// linearly interpolate horizontally between bottom neighbors
fBottomAlpha = (1 - fDeltaX) * ((clrBottomLeft >> 24) & 0xFF) + fDeltaX * ((clrBottomRight >> 24) & 0xFF);
fBottomRed = (1 - fDeltaX) * ((clrBottomLeft >> 16) & 0xFF) + fDeltaX * ((clrBottomRight >> 16) & 0xFF);
fBottomGreen = (1 - fDeltaX) * ((clrBottomLeft >> 8) & 0xFF) + fDeltaX * ((clrBottomRight >> 8) & 0xFF);
fBottomBlue = (1 - fDeltaX) * (clrBottomLeft & 0xFF) + fDeltaX * (clrBottomRight & 0xFF);
// linearly interpolate vertically between top and bottom interpolated results
iRed = (int)(Math.Round((1 - fDeltaY) * fTopRed + fDeltaY * fBottomRed));
iGreen = (int)(Math.Round((1 - fDeltaY) * fTopGreen + fDeltaY * fBottomGreen));
iBlue = (int)(Math.Round((1 - fDeltaY) * fTopBlue + fDeltaY * fBottomBlue));
iAlpha = (int)(Math.Round((1 - fDeltaY) * fTopAlpha + fDeltaY * fBottomAlpha));
// make sure color values are valid
if (iRed < 0)
{
iRed = 0;
}
if (iRed > 255)
{
iRed = 255;
}
if (iGreen < 0)
{
iGreen = 0;
}
if (iGreen > 255)
{
iGreen = 255;
}
if (iBlue < 0)
{
iBlue = 0;
}
if (iBlue > 255)
{
iBlue = 255;
}
if (iAlpha < 0)
{
iAlpha = 0;
}
if (iAlpha > 255)
{
iAlpha = 255;
}
int a = iAlpha + 1;
newp[i * newWidth + j] = (iAlpha << 24)
| ((byte)((iRed * a) >> 8) << 16)
| ((byte)((iGreen * a) >> 8) << 8)
| ((byte)((iBlue * a) >> 8));
}
}
return(bmBilinearInterpolation);
}
}
}
/// <summary>
/// Gets a BitmapContext within which to perform nested IO operations on the bitmap
/// </summary>
/// <remarks>For WPF the BitmapContext will lock the bitmap. Call Dispose on the context to unlock</remarks>
/// <param name="bmp">The bitmap.</param>
/// <param name="mode">The ReadWriteMode. If set to ReadOnly, the bitmap will not be invalidated on dispose of the context, else it will</param>
/// <returns></returns>
public static BitmapContext GetBitmapContext(this BitmapBuffer bmp, ReadWriteMode mode)
{
return(new BitmapContext(bmp, mode));
}
/// <summary>
/// Draws a series of cubic Beziér splines each defined by start, end and two control points.
/// The ending point of the previous curve is used as starting point for the next.
/// Therefore the initial curve needs four points and the subsequent 3 (2 control and 1 end point).
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="points">The points for the curve in x and y pairs, therefore the array is interpreted as (x1, y1, cx1, cy1, cx2, cy2, x2, y2, cx3, cx4 ..., xn, yn).</param>
/// <param name="color">The color for the spline.</param>
public static void DrawBeziers(this BitmapBuffer bmp, int[] points, ColorInt color)
{
bmp.DrawBeziers(points, color.ToPreMultAlphaColor());
}
/// <summary>
/// Creates an instance of a BitmapContext, with default mode = ReadWrite
/// </summary>
/// <param name="writeableBitmap"></param>
public BitmapContext(BitmapBuffer writeableBitmap)
: this(writeableBitmap, ReadWriteMode.ReadWrite)
{
}
/// <summary>
/// Creates a new cropped WriteableBitmap.
/// </summary>
/// <param name="bmp">The WriteableBitmap.</param>
/// <param name="region">The rectangle that defines the crop region.</param>
/// <returns>A new WriteableBitmap that is a cropped version of the input.</returns>
public static BitmapBuffer Crop(this BitmapBuffer bmp, RectD region)
{
return(bmp.Crop((int)region.X, (int)region.Y, (int)region.Width, (int)region.Height));
}