I have been flying some drone surveys over the ocean and need to properly project and georeference and warp my images. I have all the information I think I need: lat, lon, altitude, yaw, pitch, and roll along with sensor optics params. I have to imagine this can be done with some existing package and I had thought some rasterio functions were suitable, but I can't find any. So I've been using the cameratransform package to get the GPS positions of the corners of my image to feed into rasterio:

 

import cameratransform as ct

 

# camera parameters

 

cam = ct.Camera(ct.RectilinearProjection(focallength_mm=f,

                                         sensor=sensor_size,

                                         image=image_size),

               ct.SpatialOrientation(elevation_m=img.altitude,

                                     tilt_deg=pitch+sensor_offset,

                                     roll_deg=roll,

                                    heading_deg=yaw))

 

# gps pts are lat lon

cam.setGPSpos(img.latitude, img.longitude, img.altitude)

 

# these are the coordinates of the image corners

coords = np.array([cam.gpsFromImage([0 , 0]), \

    cam.gpsFromImage([image_size[0]-1 , 0]), \

    cam.gpsFromImage([image_size[0]-1, image_size[1]-1]), \

    cam.gpsFromImage([0 , image_size[1]-1])])

From there I'm not certain what to do. I've tried basically saying these corners are GCPs and trying to warp the image in rasterio:

 

import rasterio

 

gcp1 = rasterio.control.GroundControlPoint(row=0, col=0, x=coords[0,1], y=coords[0,0], z=coords[0,2], id=None, info=None)

gcp2 = rasterio.control.GroundControlPoint(row=image_size[0]-1, col=0, x=coords[1,1], y=coords[1,0], z=coords[1,2], id=None, info=None)

gcp3 = rasterio.control.GroundControlPoint(row=image_size[0]-1, col=image_size[1]-1, x=coords[2,1], y=coords[2,0], z=coords[2,2], id=None, info=None)

gcp4 = rasterio.control.GroundControlPoint(row=0, col=image_size[1]-1, x=coords[3,1], y=coords[3,0], z=coords[3,2], id=None, info=None)

 

# Register GDAL format drivers and configuration options with a

# context manager.

with rasterio.Env():

    

    # open the original image to get some of the basic metadata

    with rasterio.open(path_name, 'r') as src:

        profile = src.profile

                    

    # create rasterio transform

    tsfm = rasterio.transform.from_gcps([gcp1,gcp2,gcp3,gcp4])

    

    # I also tried this function but to no avail

    #tsfm = rasterio.warp.calculate_default_transform(rasterio.crs.CRS({"init": "epsg:4326"}), rasterio.crs.CRS({"init": "epsg:4326"}), img.size()[0], img.size()[1], gcps=[gcp1,gcp2,gcp3,gcp4])

 

    crs = rasterio.crs.CRS({"init": "epsg:4326"})

 

    profile.update(

        dtype=rasterio.uint8,

        transform = tsfm,

        crs=crs)

        

    with rasterio.open('example.tif', 'w', **profile) as dst:

        dst.write(src.read().astype(rasterio.uint8), 1)

This does produce an image but it is not properly warped. It is just in the correct location. Since my sensor is a 40 deg off nadir the warping should be reasonably significant, when I warp it with cameratransform's cam.getTopViewOfImage() function I get this: