使用Shapefile裁剪Raster时触发TypeError错误求助

问题重现 #

尝试用与栅格文件坐标系一致的Shapefile裁剪栅格，执行到rasterio.mask.mask时触发错误：TypeError: can't multiply sequence by non-int of type 'Affine'，原代码如下：

# Read Shapefile
with fiona.open("/content/drive/My Drive/shapefile/shape_files/lidar_shape.shp", "r") as shapefile:
    shapes = [feature["geometry"] for feature in shapefile]

# read imagery file
with rasterio.open("/content/drive/My Drive/shapefile/imagery_trans.tif") as src:
    out_image,out_transform = rasterio.mask.mask(src, shapes, crop=True)
    out_meta = src.meta

# Save clipped imagery
out_meta.update({"driver": "GTiff",
                 "height": out_image.shape[1],
                 "width": out_image.shape[2],
                 "transform": out_transform})

with rasterio.open("/content/drive/My Drive/shapefile/imagery_trans_clip.tif", "w", **out_meta) as dest:
    dest.write(out_image)

错误原因 #

这个错误的核心是传入rasterio.mask.mask的几何对象格式不符合要求：原代码读取的是Shapefile中原始的GeoJSON格式字典，而非Rasterio所需的shapely几何对象，导致在与Affine变换矩阵进行空间运算时类型不匹配。即使坐标系一致，格式错误也会触发该异常。

解决方法 #

修改代码，将GeoJSON几何转换为shapely对象，并添加坐标系验证步骤，确保两者完全匹配：

修改后的代码 #

import fiona
import rasterio
from rasterio.mask import mask
from shapely.geometry import shape
from rasterio.crs import CRS

# 读取Shapefile并转换几何为shapely对象
with fiona.open("/content/drive/My Drive/shapefile/shape_files/lidar_shape.shp", "r") as shapefile:
    shape_crs = CRS.from_wkt(shapefile.crs_wkt)
    # 过滤空几何，转换为shapely对象
    shapes = [shape(feature["geometry"]) for feature in shapefile if feature["geometry"] is not None]

# 读取栅格文件
with rasterio.open("/content/drive/My Drive/shapefile/imagery_trans.tif") as src:
    # 强制验证坐标系一致性
    assert src.crs == shape_crs, "栅格与Shapefile坐标系不匹配，请先对齐坐标系"
    out_image, out_transform = mask(src, shapes, crop=True)
    out_meta = src.meta.copy()

# 更新元数据并保存裁剪后的栅格
out_meta.update({
    "driver": "GTiff",
    "height": out_image.shape[1],
    "width": out_image.shape[2],
    "transform": out_transform
})

with rasterio.open("/content/drive/My Drive/shapefile/imagery_trans_clip.tif", "w", **out_meta) as dest:
    dest.write(out_image)

关键修改点 #

1. 导入shapely.geometry.shape，将原始GeoJSON几何字典转换为shapely几何对象，这是Rasterio mask函数的标准输入类型
2. 添加坐标系验证，用assert明确确认栅格与Shapefile的坐标系一致，避免隐性的不匹配问题
3. 过滤Shapefile中的空几何，防止无效数据干扰运算
4. 使用src.meta.copy()复制元数据，避免修改原始栅格的元数据

内容的提问来源于stack exchange，提问作者PRAJAKTA