python实现栅格图像的裁剪

 深度学习做样本必要的一步，代码如下

import os, os.path
import rasterio
from rasterio.windows import Window
import rasterio.mask

def rastersplit(input_value_raster, tile_width_in, tile_height_in, outfolder):

    dataset = rasterio.open(input_value_raster)

    # height and width of the raster
    height, width = dataset.shape

    # split the large raser into number of tiles, tile size is 2000*2000
    tile_width = tile_width_in
    tile_height = tile_height_in

    tile_num_col = int(width / tile_width + 0.5)
    tile_num_row = int(height / tile_height + 0.5)

    # the output folder
    if not os.path.exists(outfolder): os.mkdir(outfolder)

    # create each tile
    for i in range(tile_num_row):
        # re-initiate the tile width when reach the right boundary
        tile_width = tile_width_in
        row_start = i * tile_height

        # loop each column
        for j in range(tile_num_col):
            print('The i and j is:', i, j)
            tilename = os.path.join(outfolder, 'row%s-col%s.tif' % (i, j))

            col_start = j * tile_width
            row_end = (i + 1) * tile_height
            col_end = (j + 1) * tile_width

            # deal with the right boundary
            if row_end > height - 1: tile_height = height - row_start
            if col_end > width - 1: tile_width = width - col_start

            # window = get_data_window(lu_dataset.read(1, masked=True))
            window = Window(col_off=col_start, row_off=row_start, width=tile_width, height=tile_height)

            kwargs = dataset.meta.copy()
            kwargs.update({
                'height': window.height,
                'width': window.width,
                'transform': rasterio.windows.transform(window, dataset.transform)})

            img_window = dataset.read(window=window)
            if img_window.min() <= 0: continue
            with rasterio.open(tilename, 'w', **kwargs) as dst:
                dst.write(img_window)

root = 'E:DeepLearningdata'#栅格影像
data = os.path.join(root, 'landuse.tif')
label = os.path.join(root, 'result')
if not os.path.exists(label): os.mkdir(label)
tile_width = 128    #裁剪后的尺寸
tile_height = 128

rastersplit(data, tile_width, tile_height, label)