如何使用先前栅格的投影保存新栅格

Question

I tried to make an algorithm in Python where I entered a georeferenced raster (known coordinate system), all its negative values were transformed to zero, and then a new image was saved with the georeference of the initial image.

import skimage.io
import pandas as pd
import numpy as np

pathhr = 'C:\\Users\\dataset\\S30W051.tif'
HR = skimage.io.imread(pathhr)
df1 = pd.DataFrame(HR)
HR_changed = df1[df1 < 0] = 0

#save function
savedata = df1.to_numpy()
skimage.io.imsave('C:\\Users\\dataset\\S30W051_TEST.tif', savedata)

But when I save my raster at the end of this script, I get a non-georeferenced TIFF raster.

How do I keep the same coordinate system as the initial raster (without transforming the output raster into local coordinates)?

I ask for help in solving this problem. Thanks.

Answer 1

You could use rasterio for opening and saving your tiff files, and copy the metadata of the initial raster to the new raster.

import rasterio as rio

# Load the original image
with rio.open(pathhr, 'r') as r:
    HR = r.read()
    meta = r.meta

# Do any transformation you like (on the numpy array)
HR_changed = HR[HR < 0] = 0

# Save the changed raster
with rio.open('C:\\Users\\dataset\\S30W051_TEST.tif', 'w', **meta) as dst:
    dst.write(HR_change)