public Canvas CreateSimilar(int width, int height, int numChannels)
{
if (width < 0)
{
width = this.Width;
}
if (height < 0)
{
height = this.Height;
}
//if (numChannels < 1)
// numChannels = this.
PixelDataProvider pdp = this._pdp.CreateSimilar(width, height, numChannels);
Canvas c = Canvas.Create(pdp);
c.ClipRectangle = this.ClipRectangle.Copy();
return(c);
}
public static unsafe Bitmap TrimWhitespace(Bitmap bmp, out EPoint topLeftCorner)
{
//TODO: name should be TrimAlpha
int nThreshold = 0;
Canvas canvas = Canvas.Create(bmp);
canvas.Locked = true;
ERectangle rctBounds = ERectangle.FromLTRB(0, 0, canvas.Width, canvas.Height);
for (int side = 0; side < 2; side++)
{
int yDir = 1;
int yUse = 0;
if (side == 1)
{
yDir = -1;
yUse = canvas.Height - 2;
}
bool bFound = false;
for (int y = 0; y < canvas.Height; y++)
{
for (int x = 0; x < canvas.Width; x++)
{
if (canvas.GetPixel(x, yUse).A > nThreshold)
{
if (side == 0)
{
rctBounds.Top = yUse;
}
else
{
rctBounds.Bottom = yUse;
}
bFound = true;
break;
}
}
if (bFound)
{
break;
}
yUse += yDir;
}
}
for (int side = 0; side < 2; side++)
{
int xDir = 1;
int xUse = 0;
if (side == 1)
{
xDir = -1;
xUse = canvas.Width - 1;
}
bool bFound = false;
for (int x = 0; x < canvas.Width; x++)
{
xUse += xDir;
for (int y = 0; y < canvas.Height; y++)
{
if (canvas.GetPixel(xUse, y).A > nThreshold)
{
if (side == 0)
{
rctBounds.Left = xUse;
}
else
{
rctBounds.Right = xUse;
}
bFound = true;
break;
}
}
if (bFound)
{
break;
}
}
}
canvas.Locked = false;
if (rctBounds.Width == 0 || rctBounds.Height == 0)
{
topLeftCorner = new EPoint();
return(null);
}
Bitmap trimmedBmp = new Bitmap(rctBounds.Width, rctBounds.Height);
Graphics g = Graphics.FromImage(trimmedBmp);
g.DrawImage(bmp, new Rectangle(0, 0, rctBounds.Width, rctBounds.Height),
rctBounds.X, rctBounds.Y, rctBounds.Width, rctBounds.Height,
GraphicsUnit.Pixel);
topLeftCorner = new EPoint(rctBounds.X, rctBounds.Y);
return(trimmedBmp);
}
public static Canvas Create(System.Drawing.Bitmap bmp)
{
return(Canvas.Create(new PixelDataProviderGDI(bmp)));
}