theta_rectify

This is a small bash script which rectifies (levels the horizon) in Ricoh Theta (both Theta S and Theta V) spherical images using the internal pitch and roll values stored in the EXIF data. This is an alternative implementation to the THETA EXIF Library by Regen. I use his cute Lama test images for reference. All credit for the funky images go to Regen.

Install

Download, fork or copy paste the script to your machine and make it executable.

 $ chmod +x theta_rectify.sh

Use

 $ theta_rectify.sh image.jpg

The above command will rectify the image.jpg file and output a new file called image_rectified.jpg. After the first run, the script won't overwrite already rectified files, unless you use the -f option: theta_rectify -f image.jpg.

You can also bulk rectify several images at the same time passing them on the command line. For example:

 $ theta_rectify.sh *.jpg

Visual comparison between my results and those of Regen's python script show good correspondence.

Requirements

The script depends on a running copy of exiftools, imagemagick and POVRay. These tools are commonly available in most Linux distros, and can be installed on MacOS using tools such as homebrew.

On Debian and Ubuntu Linux you can install the required packages this way:

 $ sudo apt update
 $ sudo apt install imagemagick libimage-exiftool-perl povray

On MacOS first install homebrew and then install the requirements like this:

 $ brew upgrade
 $ brew install exiftool imagemagick povray

On Windows 10 you can finally get a regular Linux bash environment. Just enable the Windows Subsystem for Linux (WSL) and then install Ubuntu App from the Windows Store. Once ready, start Ubuntu app from the Windows menu and install the required packages using the above commands, as in a regular Ubuntu system. Remember that usual Windows users home directories can be acessed from the Ubuntu App at the /mnt/c/User path.