public Rectangle ContentBound(Bitmap src, RefColorMode mode = RefColorMode.Alpha)
{
Rectangle result = new Rectangle(0, 0, src.Width, src.Height);
LockBitmap lockbmp = new LockBitmap(src);
//锁定Bitmap，通过Pixel访问颜色
lockbmp.LockBits();
#region Get Ref Color value
Color cRef = lockbmp.GetPixel(0, 0);
switch (mode)
{
case RefColorMode.Alpha:
cRef = Color.Transparent;
break;
case RefColorMode.TopLeft:
cRef = lockbmp.GetPixel(0, 0);
break;
case RefColorMode.BottomRight:
cRef = lockbmp.GetPixel(lockbmp.Width - 1, lockbmp.Height - 1);
break;
}
#endregion
#region Check pixels value with Ref Value
int xMin = 0;
int xMax = lockbmp.Width - 1;
int yMin = 0;
int yMax = lockbmp.Height - 1;
var w = lockbmp.Width - 1;
var h = lockbmp.Height - 1;
var hh = (int)Math.Ceiling(lockbmp.Height / 2.0f) + 1;
var wh = (int)Math.Ceiling(lockbmp.Width / 2.0f) + 1;
#region Get Bound Top & Bottom
for (var y = 0; y < hh; y++)
{
for (var x = 0; x < w + 1; x++)
{
var yc = h - y;
Color ct = lockbmp.GetPixel(x, y);
Color cb = lockbmp.GetPixel(x, yc);
switch (mode)
{
case RefColorMode.Alpha:
if (ct.A != cRef.A)
{
if (yMin == 0)
{
yMin = y - 1;
}
}
if (cb.A != cRef.A)
{
if (yMax == h)
{
yMax = yc + 1;
}
}
break;
default:
if (ct.A != cRef.A || ct.R != cRef.R || ct.G != cRef.G || ct.B != cRef.B)
{
if (yMin == 0)
{
yMin = y - 1;
}
}
if (cb.A != cRef.A || cb.R != cRef.R || cb.G != cRef.G || cb.B != cRef.B)
{
if (yMax == h)
{
yMax = yc + 1;
}
}
break;
}
if (yMin != 0 && yMax != h)
{
break;
}
}
if (yMin != 0 && yMax != h)
{
break;
}
}
#endregion
#region Get Bound Left & Right
for (var x = 0; x < wh; x++)
{
for (var y = yMin + 1; y < yMax; y++)
{
var xc = w - x;
Color cl = lockbmp.GetPixel(x, y);
Color cr = lockbmp.GetPixel(xc, y);
switch (mode)
{
case RefColorMode.Alpha:
if (cl.A != cRef.A)
{
if (xMin == 0)
{
xMin = x - 1;
}
}
if (cr.A != cRef.A)
{
if (xMax == w)
{
xMax = xc + 1;
}
}
break;
default:
if (cl.A != cRef.A || cl.R != cRef.R || cl.G != cRef.G || cl.B != cRef.B)
{
if (xMin == 0)
{
xMin = x - 1;
}
}
if (cr.A != cRef.A || cr.R != cRef.R || cr.G != cRef.G || cr.B != cRef.B)
{
if (xMax == w)
{
xMax = xc + 1;
}
}
break;
}
if (xMin != 0 && xMax != w)
{
break;
}
}
if (xMin != 0 && xMax != w)
{
break;
}
}
#endregion
#endregion
//从内存解锁Bitmap
lockbmp.UnlockBits();
#region adjust bound size
xMin = xMin < 0 ? 0 : xMin;
xMax = xMax >= src.Width ? src.Width - 1 : xMax;
yMin = yMin < 0 ? 0 : yMin;
yMax = yMax >= src.Height ? src.Height - 1 : yMax;
result.X = xMin;
result.Y = yMin;
result.Width = (xMax - xMin) < 0 ? src.Width : xMax - xMin;
result.Height = (yMax - yMin) < 0 ? src.Height : yMax - yMin;
#endregion
return(result);
}
private void refColorModeComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
refColorMode = (RefColorMode)refColorModeComboBox.SelectedIndex;
}
private void refColorModeComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
refColorMode = (RefColorMode)refColorModeComboBox.SelectedIndex;
}