def gt_corners(gt, nx, ny):
    """Get corner coordinates based on input geotransform and raster dimensions
   """
    ul = [gt[0], gt[3]]
    ll = [gt[0], gt[3] + (gt[5] * ny)]
    ur = [gt[0] + (gt[1] * nx), gt[3]]
    lr = [gt[0] + (gt[1] * nx), gt[3] + (gt[5] * ny)]
    return ul, ll, ur, lr