read method

@override void read([ int? imageIndex ])

Read the raster accessing the file.

The optional imageIndex defines the image to open.

Implementation

@override
void read([int? imageIndex]) {
  if (imageIndex == null) {
    imageIndex = 0;
  }
  _imageBytes = _file.readAsBytesSync();
  TiffDecoder? tiffDecoder;
  if (GeoimageUtils.isTiff(_file.path)) {
    tiffDecoder = TiffDecoder();
    //_image = tiffDecoder.decodeImage(_imageBytes);
    _image = tiffDecoder.decode(_imageBytes);
  } else {
    _image = decodeImage(_imageBytes);
  }
  if (_image == null) {
    throw StateError("Unable to decode image.");
  }
  var wesnxyValues =
      GeoimageUtils.parseWorldFile(_file.path, _image!.width, _image!.height);

  var prjWkt = GeoimageUtils.getPrjWkt(_file.path);
  if (wesnxyValues != null) {
    // has worldfile
    _geoInfo = GeoInfo.fromValues(
        _image!.width,
        _image!.height,
        wesnxyValues[4],
        -wesnxyValues[5],
        wesnxyValues[0],
        wesnxyValues[3],
        prjWkt);
  } else if (tiffDecoder != null) {
    // without worldfile only tiffs can contain geoinfo
    var tiffInfo = tiffDecoder.info;
    if (tiffInfo != null) {
      _tiffImage = tiffInfo.images[imageIndex];
      if (_tiffImage != null) {
        _geoInfo = GeoInfo(_tiffImage!, prjWkt);
      }
    }
  } else {
    throw ArgumentError("The supplied image is not a supported geoimage.");
  }
}