/// <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; }