将geojson转为背景透明的图片

要将GeoJSON转换为具有透明背景的图片，您可以将代码稍微修改一下，以使用RGBA模式创建新图像，并将背景设置为透明。下面是一个示例代码：

from PIL import Image, ImageDraw
import json
import geojson

# Load GeoJSON data
with open('your_geojson_file.geojson') as f:
    data = json.load(f)

# Get bounding box coordinates
min_lon, min_lat, max_lon, max_lat = geojson.utils.coords(data)

# Calculate image size
width, height = 1024, int(1024 * ((max_lat - min_lat) / (max_lon - min_lon)))

# Create image with transparent background
img = Image.new("RGBA", (width, height), (0, 0, 0, 0))
draw = ImageDraw.Draw(img)

# Convert GeoJSON to image coordinates
coords = []
for feature in data['features']:
    geometry = feature['geometry']
    if geometry['type'] == 'Polygon':
        for polygon in geometry['coordinates']:
            xys = []
            for lon, lat in polygon:
                x = (lon - min_lon) / (max_lon - min_lon) * width
                y = height - (lat - min_lat) / (max_lat - min_lat) * height
                xys.append((x, y))
            coords.append(xys)
    elif geometry['type'] == 'LineString':
        xys = []
        for lon, lat in geometry['coordinates']:
            x = (lon - min_lon) / (max_lon - min_lon) * width
            y = height - (lat - min_lat) / (max_lat - min_lat) * height
            xys.append((x, y))
        coords.append(xys)

# Draw GeoJSON on image
for coord in coords:
    draw.polygon(coord, outline='black')

# Save image with transparent background
img.save('your_output_image.png', format='PNG')

请将上述代码按照实际情况进行修改，并确保您已经安装了Pillow和GeoJSON库。在这个示例中，我们使用了RGBA模式并将背景设置为透明。保存图像时，我们使用PNG格式，以便保留透明度信息。