lensfunpy 1.5.0

lensfunpy is an easy-to-use Python wrapper for the lensfun library.

API Documentation

Sample code

How to find cameras and lenses:

import lensfunpy

cam_maker = 'NIKON CORPORATION'
cam_model = 'NIKON D3S'
lens_maker = 'Nikon'
lens_model = 'Nikkor 28mm f/2.8D AF'

db = lensfunpy.Database()
cam = db.find_cameras(cam_maker, cam_model)[0]
lens = db.find_lenses(cam, lens_maker, lens_model)[0]

print(cam)
# Camera(Maker: NIKON CORPORATION; Model: NIKON D3S; Variant: ;
#        Mount: Nikon F AF; Crop Factor: 1.0; Score: 0)

print(lens)
# Lens(Maker: Nikon; Model: Nikkor 28mm f/2.8D AF; Type: RECTILINEAR;
#      Focal: 28.0-28.0; Aperture: 2.79999995232-2.79999995232;
#      Crop factor: 1.0; Score: 110)

How to correct lens distortion:

import cv2 # OpenCV library

focal_length = 28.0
aperture = 1.4
distance = 10
image_path = '/path/to/image.tiff'
undistorted_image_path = '/path/to/image_undist.tiff'

im = cv2.imread(image_path)
height, width = im.shape[0], im.shape[1]

mod = lensfunpy.Modifier(lens, cam.crop_factor, width, height)
mod.initialize(focal_length, aperture, distance)

undist_coords = mod.apply_geometry_distortion()
im_undistorted = cv2.remap(im, undist_coords, None, cv2.INTER_LANCZOS4)
cv2.imwrite(undistorted_image_path, im_undistorted)

It is also possible to apply the correction via SciPy instead of OpenCV. The lensfunpy.util module contains convenience functions for RGB images which handle both OpenCV and SciPy.

NumPy Dependency

Before installing lensfunpy, you need to have numpy installed. You can check your numpy version with pip freeze.

The minimum supported numpy version depends on your Python version:

Python	numpy
2.7	>= 1.7
3.4	>= 1.8
3.5 - 3.6	>= 1.11

You can install numpy with pip install numpy.

Installation on Windows and Mac OS X

Binaries are provided for Python 2.7, 3.4, 3.5, and 3.6 for both 32 and 64 bit. These can be installed with a simple pip install lensfunpy (or pip install --use-wheel lensfunpy if using pip < 1.5).

Installation on Linux

You need to have the lensfun library installed to use this wrapper.

On Ubuntu, you can get (an outdated) version with:

sudo apt-get install liblensfun0 liblensfun-dev

Or install the latest developer version from the GIT repository:

git clone git://git.code.sf.net/p/lensfun/code lensfun
cd lensfun
cmake .
sudo make install

After that, it’s the usual pip install lensfunpy.

If you get the error “ImportError: liblensfun.so.0: cannot open shared object file: No such file or directory” when trying to use lensfunpy, then do the following:

echo "/usr/local/lib" | sudo tee /etc/ld.so.conf.d/99local.conf
sudo ldconfig

The lensfun library is installed in /usr/local/lib when compiled from source, and apparently this folder is not searched for libraries by default in some Linux distributions. Note that on some systems the installation path may be slightly different, such as /usr/local/lib/x86_64-linux-gnu.