Cropping a raster file using GDAL w/ Python

Question

EDIT: PARTIAL SOLUTION

Using gdal_translate in the command line seems to do the trick, even though the Python binding doesn't work.

This worked to crop a GeoTiff removing 300 pixel padding from top and left and keeping the next 2000x2000 pixels. gdal_translate -srcwin 300 300 2000 2000 input.tif output.tif

ORIGINAL QUESTION

I've spent an embarrassingly long time trying to figure this out.

I have a series of satellite images in GEOTiff format. Each image has a 300 pixel buffer where it overlaps with the image next to it.

Goal: I am trying to crop off the 300 pixel buffer off of each image and then use as a raster with GDAL.

Constraints: 1) I need to keep all of the metadata and coordinate system information associated with the files 2) I want to do this entirely in Python (no command line)

What I've tried unsuccessfully:

1) using gdal.translate's srcWin function:

raster_data = gdal.Open('image.tif')
x_size = raster_data.RasterXSize
y_size = raster_data.RasterYSize
raster_data_unpadded = gdal.Translate('temp.tif', raster_data,
                                       srcWin = [padding,padding, 
                                       x_size - padding*2, 
                                       y_size-padding*2])

The problem: This produces a black image with no data

2) Cropping image using PIL and then saving back as TIF

 from PIL import Image
 img = Image.open(image.tif)
 x_size, y_size = img.size
 box = (padding, padding, x_size-padding, y_size - padding)
 img_unpadded = img.crop(box)
 img_unpadded.save('unpadded_image.tif')

The problem: PIL fails to save the file. It just hangs. Trying to save as a ".tiff" file produces the error "encoder error -9"

3) Using Rasterio

with rasterio.open("image.tif") as src:

    out_image, out_transform = mask(src, geoms, crop=True)

out_meta = src.meta.copy()

The problem: Rasterio doesn't seem to accept masks in Pixels format (e.g. 300 pixels). Only takes geometries, like a polygon, in the coordinate system of the file. I don't know how to translate between Pixels and coordinates.

Answer 1

The following should work:

import rasterio
from rasterio.windows import Window

with rasterio.open('input.tif') as src:
    window = Window(padding, padding, src.width - 2 * padding, src.height - 2 * padding)

    kwargs = src.meta.copy()
    kwargs.update({
        'height': window.height,
        'width': window.width,
        'transform': rasterio.windows.transform(window, src.transform)})

    with rasterio.open('cropped.tif', 'w', **kwargs) as dst:
        dst.write(src.read(window=window))