this.nativeCellType = rasterInfo.getNativeCellType();
this.bitsPerSample = nativeCellType.getBitsPerSample();
this.tileDataLength = (int) Math
.ceil(((double) pixelsPerTile * (double) bitsPerSample) / 8D);
final RasterCellType targetCellType = rasterInfo.getTargetCellType(rasterId);
this.dataFetcher = TileDataFetcher.getTileDataFetcher(this.nativeCellType, targetCellType);
int rasterIndex = rasterInfo.getRasterIndex(rasterId);
int maxTileX = rasterInfo.getNumTilesWide(rasterIndex, pyramidLevel) - 1;
int maxTileY = rasterInfo.getNumTilesHigh(rasterIndex, pyramidLevel) - 1;