def is_datasource_valid(self, ds: ogr.DataSource) -> bool:
layer_count = ds.GetLayerCount()
if layer_count == 1:
layer = ds.GetLayer(0)
# Only one layer
else:
# TODO: add support
return False
defn = layer.GetLayerDefn()
for i in range(defn.GetFieldCount()):
field_name = defn.GetFieldDefn(i).GetName()
if field_name.lower() == self.temporal_field:
field_type_code = defn.GetFieldDefn(i).GetType()
return field_type_code in self.DATETIME_TYPES
return False
def update_from_ogr_data_source(self, ds: ogr.DataSource) -> None:
layer_count = ds.GetLayerCount()
if layer_count == 1:
layer = ds.GetLayer(0)
# Only one layer
else:
# TODO: add support
return
defn = layer.GetLayerDefn()
self.layer_name = layer.GetName()
fields = []
for i in range(defn.GetFieldCount()):
field_name = defn.GetFieldDefn(i).GetName()
field_type_code = defn.GetFieldDefn(i).GetType()
fields.append(field_name)
if field_name.lower() in self.DATETIME_FIELDS:
if field_type_code not in self.DATETIME_TYPES:
self.time_field_idx = i
self.fields = fields
def make_dummy(ds: ogr.DataSource, name: str, burn: Tuple) -> ogr.DataSource:
'''Returns a dummy layer for CTMED populated with burn[1] values'''
logging.info(f'creating dummy: {name} layer')
try:
# create dummy layer
mem = create_shapefile('memory', 'MEMORY')
dummy = mem.CopyLayer(ds.GetLayer(), name, ['OVERWRITE=YES'])
# add burn field and populate
fdefn = ogr.FieldDefn(burn[0], ogr.OFTInteger)
dummy.CreateField(fdefn)
dummy.ResetReading()
for ft in dummy:
ft.SetField(burn[0], burn[1])
dummy.SetFeature(ft)
return mem
except Exception as e:
close_shapefile(ds)
raise baseException(f'dummy: {name} layer could not be created.',
baseException.ERR_CODE_LEVEL, e)
def get_first_layer(ds: ogr.DataSource) -> ogr.Layer:
return ds.GetLayer()
def round_extent(ds: ogr.DataSource, pixel_size: int) -> List[float]:
'''Gets the rounded extent'''
layer = ds.GetLayer()
extent = layer.GetExtent()
return [round(e / pixel_size) * pixel_size for e in extent]
def shp_file_to_csv(shp_ds: ogr.DataSource, raster_ds: gdal.Dataset) -> list:
"""
return a list contain the tuple (x, y, class) of the point contain of polygon shp_ds.
(x, y) is the coords of the shp_ds's spatial reference
(the same as the raster_ds's spatial reference),
the first element represent the x value,
the second element represent the y value,
the third element represent the class value.
The class value is the code of one land cover.
Parameters:
--------------
shp_ds - shape file(GeometryType is Polygon) Data source
raster_ds - raster file Dataset
Returns:
-------------
train_data_coords - The train data's list contains the item (x,y, class)
"""
# 创建一个shp
train_data_coords = []
# 获取首个图层
poly_lyr: ogr.Layer = shp_ds.GetLayer(0)
# 获取shp文件的坐标系
shp_osr: osr.SpatialReference = poly_lyr.GetSpatialRef()
shp_osr.GetAttrValue('AUTHORITY', 1) # ??? 获取对象属性值
# 获取Gtiff文件坐标系
raster_osr = osr.SpatialReference()
raster_osr.ImportFromWkt(raster_ds.GetProjection())
# 获取Gtiff文件地理变换
gtiff_geotrans = raster_ds.GetGeoTransform()
if raster_osr.GetAttrValue('AUTHORITY', 1) != shp_osr.GetAttrValue(
'AUTHORITY', 1):
print(
'Error: The shape file and the raster file have the differnet spatial refer'
)
return train_data_coords
inv_gt = gdal.InvGeoTransform(gtiff_geotrans)
# 获取要素的数量
feat_count = poly_lyr.GetFeatureCount()
# 保存训练集在栅格上的坐标（X,Y）以及地理编码值（class），需要三列
# 遍历图层获取每一要素
for feat_i in range(feat_count):
# 获取要素
poly_feat: ogr.Feature = poly_lyr.GetFeature(feat_i)
# 提取类别编码值
if 'class' not in poly_feat.keys():
print("Error: The shape file don't have the 'class' Field")
break
name = poly_feat.GetField('class')
# 从要素中获取多边形几何（是一个环）
poly_geom: ogr.Geometry = poly_feat.geometry()
if poly_geom.GetGeometryName() != 'POLYGON':
print("Error: The geometry type of shape file isn't the polygon.")
break
for ring_i in range(poly_geom.GetGeometryCount()):
# 获取多边形几何的第i个环
ring: ogr.Geometry = poly_geom.GetGeometryRef(ring_i)
# 获取几何多边形的边界(西东南北)
left, right, lower, upper = ring.GetEnvelope()
points = ring.GetPoints()
# 判断点在多边形上
# int OGRPolygon::PointOnSurface(OGRPoint * poPoint) const [virtual]
for px in np.arange(left, right, gtiff_geotrans[1]):
for py in np.arange(upper, lower, gtiff_geotrans[5]):
# 创建一个点
if point_in_poly(px, py, points):
offsets = gdal.ApplyGeoTransform(inv_gt, px, py)
# 转换为像素坐标（整数值）
xoff, yoff = map(int, offsets)
train_data_coords.append((xoff, yoff, px, py, name))
train_data_coords.append((px, py, name))
return train_data_coords