/// <summary>
/// For big images the scale that is just one step larger than the specified window will be used.
/// </summary>
/// <param name="envelope">The envelope containing the geographic extent.</param>
/// <param name="window">The rectangle containing the window extent.</param>
/// <returns>The bitmap.</returns>
public override Bitmap GetBitmap(Extent envelope, Rectangle window)
{
if (window.Width == 0 || window.Height == 0)
{
return(null);
}
if (Header?.ImageHeaders?[0] == null)
{
return(null);
}
Rectangle expWindow = window.ExpandBy(1);
Envelope expEnvelope = envelope.ToEnvelope().Reproportion(window, expWindow);
Envelope env = expEnvelope.Intersection(Bounds.Extent.ToEnvelope());
if (env == null || env.IsNull || env.Height == 0 || env.Width == 0)
{
return(null);
}
PyramidImageHeader he = Header.ImageHeaders[0];
int scale;
double cwa = expWindow.Width / expEnvelope.Width;
double cha = expWindow.Height / expEnvelope.Height;
for (scale = 0; scale < Header.ImageHeaders.Length; scale++)
{
PyramidImageHeader ph = Header.ImageHeaders[scale];
if (cwa > ph.NumColumns / Bounds.Width || cha > ph.NumRows / Bounds.Height)
{
if (scale > 0)
{
scale -= 1;
}
break;
}
he = ph;
}
RasterBounds overviewBounds = new RasterBounds(he.NumRows, he.NumColumns, he.Affine);
Rectangle r = overviewBounds.CellsContainingExtent(envelope);
if (r.Width == 0 || r.Height == 0)
{
return(null);
}
byte[] vals = ReadWindow(r.Y, r.X, r.Height, r.Width, scale);
Bitmap bmp = new Bitmap(r.Width, r.Height);
BitmapData bData = bmp.LockBits(new Rectangle(0, 0, r.Width, r.Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
Marshal.Copy(vals, 0, bData.Scan0, vals.Length);
bmp.UnlockBits(bData);
// Use the cell coordinates to determine the affine coefficients for the cells retrieved.
double[] affine = new double[6];
Array.Copy(he.Affine, affine, 6);
affine[0] = affine[0] + (r.X * affine[1]) + (r.Y * affine[2]);
affine[3] = affine[3] + (r.X * affine[4]) + (r.Y * affine[5]);
if (window.Width == 0 || window.Height == 0)
{
return(null);
}
Bitmap result = new Bitmap(window.Width, window.Height);
Graphics g = Graphics.FromImage(result);
// Gets the scaling factor for converting from geographic to pixel coordinates
double dx = window.Width / envelope.Width;
double dy = window.Height / envelope.Height;
double[] a = affine;
// gets the affine scaling factors.
float m11 = Convert.ToSingle(a[1] * dx);
float m22 = Convert.ToSingle(a[5] * -dy);
float m21 = Convert.ToSingle(a[2] * dx);
float m12 = Convert.ToSingle(a[4] * -dy);
double l = a[0] - (.5 * (a[1] + a[2])); // Left of top left pixel
double t = a[3] - (.5 * (a[4] + a[5])); // top of top left pixel
float xShift = (float)((l - envelope.MinX) * dx);
float yShift = (float)((envelope.MaxY - t) * dy);
g.Transform = new Matrix(m11, m12, m21, m22, xShift, yShift);
g.PixelOffsetMode = PixelOffsetMode.Half;
if (m11 > 1 || m22 > 1)
{
g.InterpolationMode = InterpolationMode.NearestNeighbor;
}
g.DrawImage(bmp, new PointF(0, 0));
bmp.Dispose();
g.Dispose();
return(result);
}
/// <summary>
/// For big images the scale that is just one step larger than the specified window will be used.
/// </summary>
/// <param name="envelope"></param>
/// <param name="window"></param>
/// <returns></returns>
public override Bitmap GetBitmap(Extent envelope, Rectangle window)
{
if (window.Width == 0 || window.Height == 0) return null;
if (_header == null) return null;
if (_header.ImageHeaders == null) return null;
if (_header.ImageHeaders[0] == null) return null;
Rectangle expWindow = window.ExpandBy(1);
IEnvelope expEnvelope = envelope.ToEnvelope().Reproportion(window, expWindow);
IEnvelope env = expEnvelope.Intersection(Bounds.Extent.ToEnvelope());
if (env == null || env.IsNull || env.Height == 0 || env.Width == 0) return null;
PyramidImageHeader he = _header.ImageHeaders[0];
int scale;
double cwa = expWindow.Width / expEnvelope.Width;
double cha = expWindow.Height / expEnvelope.Height;
for (scale = 0; scale < _header.ImageHeaders.Length; scale++)
{
PyramidImageHeader ph = _header.ImageHeaders[scale];
if (cwa > ph.NumColumns / Bounds.Width || cha > ph.NumRows / Bounds.Height)
{
if (scale > 0) scale -= 1;
break;
}
he = ph;
}
RasterBounds overviewBounds = new RasterBounds(he.NumRows, he.NumColumns, he.Affine);
Rectangle r = overviewBounds.CellsContainingExtent(envelope);
if (r.Width == 0 || r.Height == 0) return null;
byte[] vals = ReadWindow(r.Y, r.X, r.Height, r.Width, scale);
Bitmap bmp = new Bitmap(r.Width, r.Height);
BitmapData bData = bmp.LockBits(new Rectangle(0, 0, r.Width, r.Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
Marshal.Copy(vals, 0, bData.Scan0, vals.Length);
bmp.UnlockBits(bData);
// Use the cell coordinates to determine the affine coefficients for the cells retrieved.
double[] affine = new double[6];
Array.Copy(he.Affine, affine, 6);
affine[0] = affine[0] + r.X * affine[1] + r.Y * affine[2];
affine[3] = affine[3] + r.X * affine[4] + r.Y * affine[5];
if (window.Width == 0 || window.Height == 0)
{
return null;
}
Bitmap result = new Bitmap(window.Width, window.Height);
Graphics g = Graphics.FromImage(result);
//
// Gets the scaling factor for converting from geographic to pixel coordinates
double dx = (window.Width / envelope.Width);
double dy = (window.Height / envelope.Height);
double[] a = affine;
// gets the affine scaling factors.
float m11 = Convert.ToSingle(a[1] * dx);
float m22 = Convert.ToSingle(a[5] * -dy);
float m21 = Convert.ToSingle(a[2] * dx);
float m12 = Convert.ToSingle(a[4] * -dy);
float l = (float)(a[0] - .5 * (a[1] + a[2])); // Left of top left pixel
float t = (float)(a[3] - .5 * (a[4] + a[5])); // top of top left pixel
float xShift = (float)((l - envelope.MinX) * dx);
float yShift = (float)((envelope.MaxY - t) * dy);
g.Transform = new Matrix(m11, m12, m21, m22, xShift, yShift);
g.PixelOffsetMode = PixelOffsetMode.Half;
if (m11 > 1 || m22 > 1)
{
g.InterpolationMode = InterpolationMode.NearestNeighbor;
}
g.DrawImage(bmp, new PointF(0, 0));
bmp.Dispose();
g.Dispose();
return result;
}
