如何将在scikit图像find_contours中创建的轮廓导出到shapefile或geojson?
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我正在尝试在卫星图像上运行后将scikit-image.measure.find_contours()函数的结果导出为shapefile或geojson.
输出是像(行,列)这样的数组,其轮廓沿坐标,其中有很多.
如何绘制各种轮廓的坐标,并将其导出到shapefile(可以设置适当的投影等)?
我当前的代码,其中“ mask”是我处理过的图像:
from skimage import measure
import matplotlib.pyplot as plt
contours = measure.find_contours(mask, 0.5)
plt.imshow(mask)
for n, contour in enumerate(contours):
plt.plot(contour[:,1], contour[:, 0], linewidth=1)
解决方法:
由rasterio和fiona的主要开发人员改编为post的以下内容应该可以正常工作,尽管我敢肯定您需要进行更多调整.它使用rasterio.features.shapes来识别图像中具有一定值的连续区域,并根据栅格的变换返回相关联的坐标.然后使用fiona将这些记录写入shapefile.
import fiona
import rasterio.features
schema = {"geometry": "Polygon", "properties": {"value": "int"}}
with rasterio.open(raster_filename) as raster:
image = raster.read()
# use your function to generate mask
mask = your_thresholding_function(image)
# and convert to uint8 for rasterio.features.shapes
mask = mask.astype('uint8')
shapes = rasterio.features.shapes(mask, transform=raster.transform)
# select the records from shapes where the value is 1,
# or where the mask was True
records = [{"geometry": geometry, "properties": {"value": value}}
for (geometry, value) in shapes if value == 1]
with fiona.open(shape_filename, "w", "ESRI Shapefile",
crs=raster.crs.data, schema=schema) as out_file:
out_file.writerecords(records)
标签:contour,scikit-image,shapefile,arrays,python 来源: https://codeday.me/bug/20191111/2022949.html