/// <summary>
/// Finds the smallest and largest Y coordinates of the pixels whose alpha channel
/// exceeds the specified threshold. The X coordinates of the result cover the entire image.
/// </summary>
public PixelRect PreciseHeight(int alphaThreshold = 0, int left = 0, int width = -1)
{
if (width < 0)
{
width = Width;
}
using (UseRead())
return(PixelRect.FromTopBottom(PreciseTop(alphaThreshold, left, width), PreciseBottom(alphaThreshold, left, width)));
}
