public override bool Read(string filename, ProgressInfo progress, out PatchData data)
{
data = null;
using (var geoTiff = new GeoTiff(filename))
{
if (geoTiff == null)
{
return(false);
}
var bouds = geoTiff.Bounds;
GridData grid = new GridData
{
north = bouds.north,
east = bouds.east,
west = bouds.west,
south = bouds.south,
};
grid.countX = geoTiff.Width;
grid.countY = geoTiff.Height;
grid.InitGridValues(false);
// Read raster values
int width = grid.countX;
int height = grid.countY;
int bufferSize = width * height;
int bytesPerSample = geoTiff.BitsPerSample / 8;
var dataType = geoTiff.DataType;
if (dataType == null)
{
switch (geoTiff.BitsPerSample)
{
case 8:
dataType = typeof(byte);
break;
case 16:
dataType = typeof(UInt16);
break;
case 32:
dataType = typeof(UInt32);
break;
case 64:
dataType = typeof(UInt64);
break;
}
}
ValueConverter convert = ConverterMap[dataType];
if (geoTiff.Tiff.IsTiled())
{
int tileCount = geoTiff.Tiff.NumberOfTiles();
int bytesPerTileRow = geoTiff.Tiff.TileRowSize();
int tileWidth = 0, tileHeight = 0;
tileWidth = bytesPerTileRow / bytesPerSample;
tileHeight = bytesPerTileRow / bytesPerSample;
int tilesPerRow = Mathf.CeilToInt((float)width / tileWidth);
int bytesPerTile = geoTiff.Tiff.TileSize();
byte[] buffer = new byte[bytesPerTile];
int offset, index = 0;
float progressStep = 1f / tileCount;
for (int tile = 0; tile < tileCount; tile++)
{
geoTiff.Tiff.ReadEncodedTile(tile, buffer, 0, bytesPerTile);
int tileX = tile % tilesPerRow;
int tileY = tile / tilesPerRow;
int xOffset = tileX * tileWidth;
int yOffset = tileY * tileHeight;
index = yOffset * width + xOffset;
offset = 0;
int w = Math.Min(width, xOffset + tileWidth) - xOffset;
int h = Math.Min(height, yOffset + tileHeight) - yOffset;
for (int r = 0; r < h; r++)
{
for (int c = 0; c < w; c++)
{
grid.values[index++] = convert(buffer, offset);
offset += bytesPerSample;
}
index += width - w;
offset += (tileWidth - w) * bytesPerSample;
}
progress.value += progressStep;
}
}
else
{
int scanlineSize = width * bytesPerSample;
byte[] buffer = new byte[scanlineSize];
int offset, index = 0;
float progressStep = 1f / grid.countY;
for (int r = 0; r < height; r++)
{
offset = 0;
geoTiff.Tiff.ReadScanline(buffer, r);
for (int c = 0; c < width; c++)
{
grid.values[index++] = convert(buffer, offset);
offset += bytesPerSample;
}
progress.value += progressStep;
}
}
progress.value = 1;
grid.AddMaskValue((float)geoTiff.NoDataValue);
var citation = geoTiff.Citation;
if (!string.IsNullOrWhiteSpace(citation))
{
grid.AddMetadata("Citation", citation);
}
data = grid;
}
return(true);
}
