public void Reproject_DifferentCoordinateSystems_ReprojectImageAndMetaData()
{
// Setup
var mapArgs = new MapArgs(new Rectangle(0, 0, 722, 349),
new Extent(520981.864447542, 6853700.54100246, 709995.365081098, 6945065.79269375));
ProjectionInfo sourceProjection = ProjectionInfo.FromEpsgCode(25831);
ProjectionInfo targetProjection = KnownCoordinateSystems.Projected.World.WebMercator;
var projector = new TileReprojector(mapArgs, sourceProjection, targetProjection);
var sourceReference = new WorldFile(140, 0.0, 0.0, -140, 641716.59261121, 5825498);
Bitmap sourceTile = Resources.source;
WorldFile targetReference;
Bitmap targetTile;
// Call
projector.Reproject(sourceReference, sourceTile, out targetReference, out targetTile);
// Assert
// Note: These ground truth values have been defined using https://github.com/FObermaier/DotSpatial.Plugins/blob/master/DotSpatial.Plugins.BruTileLayer/Reprojection/TileReprojector.cs
Assert.AreEqual(261.791552124038, targetReference.A11, 1e-8);
Assert.AreEqual(0.0, targetReference.A21);
Assert.AreEqual(0.0, targetReference.A12);
Assert.AreEqual(-261.79155212403651, targetReference.A22, 1e-8);
Assert.AreEqual(564962.84520438069, targetReference.B1, 1e-8);
Assert.AreEqual(6902131.9781454066, targetReference.B2, 1e-8);
TestHelper.AssertImagesAreEqual(Resources.target, targetTile);
}
/// <summary>
/// Reprojects a <see cref="Bitmap"/> and corresponding georeferenced metadata to
/// a new coordinate system.
/// </summary>
/// <param name="sourceReference">The georeferenced metadata of <paramref name="sourceTile"/>.</param>
/// <param name="sourceTile">The tile image.</param>
/// <param name="targetReference">Output: The reprojected georeferenced metadata.</param>
/// <param name="targetTile">Output: The reprojected tile image.</param>
public void Reproject(WorldFile sourceReference, Bitmap sourceTile, out WorldFile targetReference, out Bitmap targetTile)
{
if (source == null || target == null || source.Equals(target))
{
targetReference = sourceReference;
targetTile = sourceTile;
return;
}
Rectangle targetTileExtentInPixelCoordinates = GetTargetExtentInPixelCoordinates(sourceReference, sourceTile);
// Get the intersection with the current viewport
targetTileExtentInPixelCoordinates.Intersect(mapArgs.ImageRectangle);
// Is it empty, don't return anything
if (targetTileExtentInPixelCoordinates.Width == 0 || targetTileExtentInPixelCoordinates.Height == 0)
{
targetTile = null;
targetReference = null;
return;
}
int offsetX = targetTileExtentInPixelCoordinates.X;
int offsetY = targetTileExtentInPixelCoordinates.Y;
// Prepare the result tile
targetTile = new Bitmap(targetTileExtentInPixelCoordinates.Size.Width, targetTileExtentInPixelCoordinates.Size.Height,
PixelFormat.Format32bppArgb);
using (Graphics g = Graphics.FromImage(targetTile))
{
g.Clear(Color.Transparent);
}
ColorAccess sourceTileColorAccess = ColorAccess.Create(sourceTile);
ColorAccess targetTileColorAccess = ColorAccess.Create(targetTile);
// Copy values to output buffer
Size sourceTileSize = sourceTile.Size;
for (var i = 0; i < targetTile.Height; i++)
{
foreach (Tuple <Point, Point> ppair in
GetValidPoints(offsetY + i, offsetY, offsetX, offsetX + targetTile.Width, sourceReference, sourceTileSize))
{
Color c = sourceTileColorAccess[ppair.Item1.X, ppair.Item1.Y];
targetTileColorAccess[ppair.Item2.X, ppair.Item2.Y] = c;
}
}
// Copy to output tile
targetTileColorAccess.SetBufferToImageAtOriginalLocation(targetTile);
// Compute the reference
Extent outExtent = mapArgs.PixelToProj(targetTileExtentInPixelCoordinates);
targetReference = new WorldFile(
outExtent.Width / targetTileExtentInPixelCoordinates.Width, 0,
0, -outExtent.Height / targetTileExtentInPixelCoordinates.Height,
outExtent.X, outExtent.Y);
}
private IEnumerable <Tuple <Point, Point> > GetValidPoints(int y, int offsetY, int x1, int x2,
WorldFile sourceReference, Size sourceTileSize)
{
int len = x2 - x1;
var xy = new double[len * 2];
var i = 0;
for (int x = x1; x < x2; x++)
{
Coordinate c = mapArgs.PixelToProj(new Point(x, y));
xy[i] = c.X;
xy[i + 1] = c.Y;
i = i + 2;
}
DotSpatialReproject.ReprojectPoints(xy, null, target, source, 0, len);
i = 0;
y -= offsetY;
for (var x = 0; x < len; x++)
{
var coord = new Coordinate(xy[i++], xy[i++]);
Point sourcePixelLocation = sourceReference.ToScreenCoordinates(coord);
if (IsSourcePointInsideArea(sourceTileSize, sourcePixelLocation))
{
yield return(Tuple.Create(sourcePixelLocation, new Point(x, y)));
}
}
}
private Rectangle GetTargetExtentInPixelCoordinates(WorldFile sourceReference, Bitmap sourceTile)
{
IPolygon sourceTileCircumference = sourceReference.BoundingOrdinatesToWorldCoordinates(sourceTile.Width, sourceTile.Height);
ILinearRing targetTileCircumference = sourceTileCircumference.Shell.Reproject(source, target);
Extent targetTileExtent = targetTileCircumference.EnvelopeInternal.ToExtent();
return(mapArgs.ProjToPixel(targetTileExtent));
}
public void Reproject_SameProjection_ReturnSourceMaterial()
{
// Setup
ProjectionInfo projection = KnownCoordinateSystems.Projected.NationalGrids.Rijksdriehoekstelsel;
var mapArgs = new MapArgs(new Rectangle(), new Extent());
var projector = new TileReprojector(mapArgs, projection, projection);
var sourceReference = new WorldFile(1.0, 0.0, 0.0, -1.0, 0.0, 0.0);
Bitmap sourceTile = Resources.testImage;
WorldFile targetReference;
Bitmap targetTile;
// Call
projector.Reproject(sourceReference, sourceTile, out targetReference, out targetTile);
// Assert
Assert.AreSame(sourceReference, targetReference);
Assert.AreSame(sourceTile, targetTile);
}
public void Reproject_TargetTileWouldNotBeVisibleInViewport_ReturnNull()
{
// Setup
ProjectionInfo sourceProjection = KnownCoordinateSystems.Projected.NationalGrids.Rijksdriehoekstelsel;
ProjectionInfo targetProjection = KnownCoordinateSystems.Projected.World.WebMercator;
var mapArgs = new MapArgs(new Rectangle(0, 0, 10, 10), new Extent(5, 50, 10, 100));
var projector = new TileReprojector(mapArgs, sourceProjection, targetProjection);
var sourceReference = new WorldFile(1.0, 0.0, 0.0, -1.0, 0.0, 0.0);
Bitmap sourceTile = Resources.testImage;
WorldFile targetReference;
Bitmap targetTile;
// Call
projector.Reproject(sourceReference, sourceTile, out targetReference, out targetTile);
// Assert
Assert.IsNull(targetReference);
Assert.IsNull(targetTile);
}
