decrispell

import numpy as np

def normals_from_xyz(xyz, smooth_sigma=None):
    """
    Given a 3-plane float image containing x,y,z coordinates,
    compute the surface normals at each pixel.
    Returns a 3-plane floating point image with nx,ny,nz per pixel.
    """
    if smooth_sigma is not None:
        xyz = np.array(xyz)  # make copy of input

decrispell

import rasterio

# load the geotiff (a DSM in this case) and read the data - only one index in this case
dsm = rasterio.open(dsm_fname)
dsm_data = dsm.read()[0]

# crop the data
dsm_crop = dsm_data[min_y:min_y+height, min_x:min_x+width]

# make a copy of the geotiff metadata

decrispell

/**
 * Convert standard camera intrinsic and extrinsic parameters to a vtkCamera instance for rendering
 * Assume square pixels and 0 skew (for now).
 *
 * focal_len : camera focal length (units pixels)
 * nx,ny : image dimensions in pixels
 * principal_pt: camera principal point,
 *    i.e. the intersection of the principal ray with the image plane (units pixels)
 * camera_rot, camera_trans : rotation, translation matrix mapping world points to camera coordinates
 * depth_min, depth_max : needed to set the clipping range