实现水体含量反演程序。

extract_water_area.py

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+from util import *
+from osgeo import gdal
+import argparse
+
+
+def xml2shp():
+    pass
+
+
+def rasterize_envi_xml(shp_filepath):
+    pass
+
+
+@timeit
+def rasterize_shp(shp_filepath, raster_fn_out, img_path, NoData_value=0):
+    dataset = gdal.Open(img_path)
+    im_width = dataset.RasterXSize
+    im_height = dataset.RasterYSize
+    geotransform = dataset.GetGeoTransform()
+    imgdata_in = dataset.GetRasterBand(1).ReadAsArray()
+    del dataset
+
+    # Open the data source and read in the extent
+    source_ds = gdal.OpenEx(shp_filepath)
+    # about 25 metres(ish) use 0.001 if you want roughly 100m
+    pixel_size = geotransform[1]
+    raster_fn_out_tmp = append2filename(raster_fn_out, "_tmp_delete")
+    gdal.Rasterize(raster_fn_out_tmp, source_ds, format='envi', outputType=gdal.GDT_Byte,
+                   noData=NoData_value, initValues=NoData_value, xRes=pixel_size, yRes=-pixel_size, allTouched=True,
+                   burnValues=1)
+
+    dataset_tmp = gdal.Open(raster_fn_out_tmp)
+    geotransform_tmp = dataset_tmp.GetGeoTransform()
+    inv_geotransform_tmp = gdal.InvGeoTransform(geotransform_tmp)
+    data_tmp = dataset_tmp.GetRasterBand(1).ReadAsArray()
+    del dataset_tmp
+
+    # 创建和输入影像相同行列号、相同分辨率的水域掩膜，方便后续使用
+    water_mask = np.zeros((im_height, im_width))
+    for row in range(im_height):
+        for column in range(im_width):
+            coor = gdal.ApplyGeoTransform(geotransform, column, row)
+
+            coor_pixel = gdal.ApplyGeoTransform(inv_geotransform_tmp, coor[0], coor[1])
+            coor_pixel = [int(num) for num in coor_pixel]
+
+            if coor_pixel[0] < 0 or coor_pixel[0] >= data_tmp.shape[1]:
+                continue
+            if coor_pixel[1] < 0 or coor_pixel[1] >= data_tmp.shape[0]:
+                continue
+
+            if imgdata_in[row, column] == 0:  # 当shp区域比影像区域大时，略过
+                continue
+
+            water_mask[row, column] = data_tmp[coor_pixel[1], coor_pixel[0]]
+
+    write_bands(img_path, raster_fn_out, water_mask)
+
+    os.remove(raster_fn_out_tmp)
+
+
+def calculate_NDWI(green_bandnumber, nir_bandnumber, filename):
+    dataset = gdal.Open(filename)  # 打开文件
+    num_bands = dataset.RasterCount  # 栅格矩阵的波段数
+    im_geotrans = dataset.GetGeoTransform()  # 仿射矩阵
+    im_proj = dataset.GetProjection()  # 地图投影信息
+
+    tmp = dataset.GetRasterBand(green_bandnumber + 1)  # 波段计数从1开始
+    band_green = tmp.ReadAsArray().astype(np.int16)
+    tmp = dataset.GetRasterBand(nir_bandnumber + 1)  # 波段计数从1开始
+    band_nir = tmp.ReadAsArray().astype(np.int16)
+
+    ndwi = (band_green - band_nir) / (band_green + band_nir)
+
+    del dataset
+
+    return ndwi
+
+
+def extract_water(ndwi, threshold=0.3, data_ignore_value=0):
+    water_region = np.where(ndwi > threshold, 1, data_ignore_value)
+
+    return water_region
+
+
+def ndwi(file_path, ndwi_threshold=0.4, output_path=None, data_ignore_value=0):
+    if output_path is None:
+        output_path = append2filename(file_path, "_waterarea")
+
+    dataset_in = gdal.Open(file_path)
+    im_width_in = dataset_in.RasterXSize  # 栅格矩阵的列数
+    im_height_in = dataset_in.RasterYSize  # 栅格矩阵的行数
+    num_bands_in = dataset_in.RasterCount  # 栅格矩阵的波段数
+    geotrans_in = dataset_in.GetGeoTransform()  # 仿射矩阵
+    proj_in = dataset_in.GetProjection()  # 地图投影信息
+    del dataset_in
+
+    green_wave = 552.19
+    nir_wave = 809.2890
+    green_band_number = find_band_number(green_wave, file_path)
+    nir_band_number = find_band_number(nir_wave, file_path)
+
+    ndwi = calculate_NDWI(green_band_number, nir_band_number, file_path)
+
+    water_binary = extract_water(ndwi, threshold=ndwi_threshold)  # 0.4
+
+    write_bands(file_path, output_path, water_binary)
+
+    return output_path
+
+
+def main():
+    parser = argparse.ArgumentParser(description="此程序用于提取水域区域，输出的水域栅格和输入的影像具有相同的行列数。")
+
+    # parser.add_argument("--global_arg", type=str, help="A global argument for all modes", required=True)
+
+    # 创建子命令解析器
+    subparsers = parser.add_subparsers(dest="algorithm", required=True, help="Choose a mode")
+
+    rasterize_shp_ = subparsers.add_parser("rasterize_shp", help="Mode 1 description")
+    rasterize_shp_.add_argument('-i1', '--img_path', type=str, required=True, help='输入影像文件的路径')
+    rasterize_shp_.add_argument('-i2', '--shp_path', type=str, required=True, help='输入shp文件的路径')
+    rasterize_shp_.add_argument('-o', '--water_mask_outpath', required=True, type=str, help='输出水体掩膜文件的路径')
+    rasterize_shp_.set_defaults(func=rasterize_shp)
+
+    ndwi_ = subparsers.add_parser("ndwi", help="Mode 2 description")
+    ndwi_.add_argument('-i1', '--img_path', type=str, required=True, help='输入影像文件的路径')
+    ndwi_.add_argument('-i2', '--ndwi_threshold', type=float, required=True, help='输入ndwi水体阈值，大于此值的为水域')
+    ndwi_.add_argument('-o', '--water_mask_outpath', required=True, type=str, help='输出水体掩膜文件的路径')
+    ndwi_.set_defaults(func=ndwi)
+
+    # 解析参数
+    args = parser.parse_args()
+    if args.algorithm == "rasterize_shp":
+        args.func(args.shp_path, args.water_mask_outpath, args.img_path)
+    elif args.algorithm == "ndwi":
+        args.func(args.img_path, args.ndwi_threshold, args.water_mask_outpath)
+
+
+# Press the green button in the gutter to run the script.
+if __name__ == '__main__':
+    main()