rasterio: center crop geotiff, profiles and window_transform

Question

I'm trying to do a simple center crop of as square geotiff using rasterio.

I crop the image using numpy, which works as expected, then update the image profile's height and width.

I also update the affine transform using src.window_transform, but I am doing something wrong. The affine transform ends up being incorrect.

My code is below. Can anyone tell me where I am messing up? Thanks.

CODE:

import rasterio as rio

#
# FUNCTIONS
#
def get_image_and_profile(path):
    with rio.open(path) as src:
        profile=src.profile
        image=src.read()
    return image, profile


def image_write(im,path,profile):
    with rio.open(path,'w',**profile) as dst:
        dst.write(im)


def crop_image(image,crp):
    return image[:,crp:-crp,crp:-crp]


def crop_profile(profile,out_size,crp):
    win=(
        (crp,out_size+crp),
        (crp,out_size+crp))
    profile=profile.copy()
    profile.pop('transform',None)
    profile['width']=out_size
    profile['height']=out_size
    profile['affine']=src.window_transform(win)
    return profile



#
# CROP GEOTIFF
#
path='input.tif'
out_path='output.tif'
crp=92

im,profile=get_image_and_profile(path)
im=crop_image(im,crp)
profile=crop_profile(profile,im.shape[1],crp)
image_write(im,out_path,profile)

Answer 1

Your window seems off, should be

rasterio.windows.Window(col_off, row_off, width, height)

so:

rasterio.windows.Window(crp, crp, img.shape1, img.shape[0])