def _pixel_sz_trans(ds: gdal.Dataset, ps: float) -> gdal.Dataset:
""" Resize the image by pixel size. """
ds_trans = ds.GetGeoTransform()
factor = ds_trans[1] / ps
if list(ds_trans)[:2] == [0.0, 1.0] or round(factor, 2) == 1:
return ds
ds_proj = ds.GetProjection()
ds_dtype = ds.GetRasterBand(1).DataType
width, height = ds.RasterXSize, ds.RasterYSize
ts_trans = list(ds_trans)
ts_trans[1] = ps
ts_trans[5] = -ps
mem_drv = gdal.GetDriverByName('MEM')
dst_ds = mem_drv.Create('', int(width * factor), int(height * factor),
ds.RasterCount, ds_dtype)
dst_ds.SetProjection(ds_proj)
dst_ds.SetGeoTransform(ts_trans)
gdal.ReprojectImage(ds, dst_ds, ds_proj, ds_proj,
gdalconst.GRA_CubicSpline)
return dst_ds
def make_raster(in_ds: gdal.Dataset,
fn: str,
data: np.ndarray,
data_type: object,
Nodata=None) -> gdal.Dataset:
"""Create a one-band GeoTIFF.
Parameters:
------------
in_ds - datasource to copy projection and geotransfrom from
fn - path to the file to create
data - NUmpy array containing data to write
data_type - output data type
nodata - optional NoData value
Returns:
------------
out_ds - datasource to output
"""
driver = gdal.GetDriverByName('GTiff')
out_ds = driver.Create(fn, in_ds.RasterXSize, in_ds.RasterYSize, 1,
data_type)
out_ds: gdal.Dataset
# 从输入数据源中复制投影（坐标系信息）
out_ds.SetProjection(in_ds.GetProjection())
# 从输入数据源中复制地理变换
out_ds.SetGeoTransform(in_ds.GetGeoTransform())
out_band = out_ds.GetRasterBand(1)
out_band: gdal.Band
if Nodata is not None:
out_band.SetNoDataValue(Nodata)
out_band.WriteArray(data)
out_band.FlushCache()
out_band.ComputeStatistics(False)
return out_ds
def write_mask_to_file(f: gdal.Dataset, file_name: str,
mask: np.ndarray) -> None:
(width, height) = mask.shape
out_image = gdal.GetDriverByName('GTiff').Create(file_name,
height,
width,
bands=1)
out_image.SetProjection(f.GetProjection())
out_image.SetGeoTransform(f.GetGeoTransform())
out_image.GetRasterBand(1).WriteArray(mask)
out_image.FlushCache()
def world_to_pixel(image_dataset: gdal.Dataset, longitude: float,
latitude: float) -> (int, int):
geotransform = image_dataset.GetGeoTransform()
ulx, uly = geotransform[0], geotransform[3]
x_dist = geotransform[1]
x = np.round((longitude - uly) / x_dist).astype(np.int)
y = np.round((uly - latitude) / x_dist).astype(np.int)
return x, y
def _create_blank_raster(
in_data_set: gdal.Dataset,
out_raster_path: Path,
nr_bands: int = 1,
no_data: float = np.nan,
e_type: int = 6,
):
"""Takes input data set and creates new raster. It copies input data set size, projection and geo info."""
gtiff_driver = gdal.GetDriverByName("GTiff")
band = in_data_set.GetRasterBand(1)
x_size = band.XSize # number of columns
y_size = band.YSize # number of rows
out_ds = gtiff_driver.Create(out_raster_path.as_posix(),
xsize=x_size,
ysize=y_size,
bands=nr_bands,
eType=e_type,
options=["BIGTIFF=IF_NEEDED"])
out_ds.SetProjection(in_data_set.GetProjection())
out_ds.SetGeoTransform(in_data_set.GetGeoTransform())
out_ds.GetRasterBand(1).SetNoDataValue(no_data)
out_ds.FlushCache()
out_ds = None
def gdal_to_json(ds: gdal.Dataset):
gt = ds.GetGeoTransform(can_return_null=True)
xsize = ds.RasterXSize
ysize = ds.RasterYSize
srs = get_srs(ds)
srs = srs.ExportToProj4()
minx = gt[0] + gt[1] * 0 + gt[2] * 0
miny = gt[3] + gt[4] * 0 + gt[5] * 0
maxx = gt[0] + gt[1] * xsize + gt[2] * ysize
maxy = gt[3] + gt[4] * xsize + gt[5] * ysize
bbox = miny, minx, maxy, maxx
band_list = range(1, ds.RasterCount + 1)
data = [
ds.ReadAsArray(band_list=[bnd]).ravel().tolist() for bnd in band_list
]
ndv = [ds.GetRasterBand(i).GetNoDataValue() for i in band_list]
result = dict(bbox=bbox,
gt=gt,
srs=srs,
size=(xsize, ysize),
data=data,
ndv=ndv)
return result
def get_geotransform_and_size(
ds: gdal.Dataset) -> Tuple[GeoTransform, Tuple[int, int]]:
return ds.GetGeoTransform(), (ds.RasterXSize, ds.RasterYSize)
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
def shp_files_to_csv(shp_files: list, raster_ds: gdal.Dataset,
out_csv_file) -> 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_files - list of 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 = []
for i in range(len(shp_files)):
code = i + 1
shp_ds = ogr.Open(shp_files[i])
print(shp_files[i])
# 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Gtiff文件坐标系
raster_osr = osr.SpatialReference() # 获取地理参考系统
raster_osr.ImportFromWkt(
raster_ds.GetProjection()) # 从一个WKT定义的坐标系统来构造一个SpatialReference类对象
# 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)
# 没有编码值
# 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, code))
#train_data_coords.append((px, py, code))
df = pd.DataFrame(train_data_coords,
columns=['xoff', 'yoff', 'px', 'py', 'class'])
df.to_csv(out_csv_file)
del shp_ds
print('train.csv have successfully write in.')
return train_data_coords
def get_dataset_geometry(dataset: gdal.Dataset) -> (List[int], List[int]):
""" Get the geometry info (origin and pixel size) of the dataset.
"""
return dataset.GetGeoTransform()
def _load_geotransform(self, image_dataset: gdal.Dataset) -> Geotransform:
return Geotransform.from_tuple(image_dataset.GetGeoTransform())
