Phoros

Workflow
Command Line Interface
Web Interface
Deployment
Licence
Acknowledgements

A Tool for Photogrammetric Road Survey

Workflow

Images and GPS data are acquired using a measuring vehicle. (Here is a working example.)
Sequences of a few hundred images together with their trigger times are stored Huffman-encoded in files called *.pictures. GPS data is preprocessed into a table of ASCII text. The format of both image and GPS files is not (yet) explained here.
Cameras and GPS system need to be calibrated, which is not explained here.
Calibration parameters are stored into the database using the Command Line Interface (There, cf. Camera Hardware Parameters through Camera Calibration Parameters.)
GPS data and image information are fed into the database using option --store-images-and-points of the Command Line Interface.
Presentation project users use the web interface to point in a map at a point of interest and are shown a couple of relevant images. In these images they point at features of interest the coordinates of which can be stored into the database. (Storage not yet implemented; coordinates are just shown.)

Command Line Interface

The command line interface is used to

initialize a fresh PostgreSQL database (./phoros --create-sys-tables ...),
set up and manage acquisition projects (./phoros --create-acquisition-project ...),
store camera calibration parameters (--store-camera-hardware, --store-device-stage-of-life, --store-camera-calibration etc.),
store measurement data, i.e., images and GPS positions (./phoros --store-images-and-points ...),
manage presentation projects and presentation project users (--create-presentation-project, --create-user etc.),
start Phoros as a presentation server (a web server presenting measurement data to presentation project users) by ./phoros --server ....

$ ./phoros --help

emits a rather comprehensive help message.

Web Interface

Once images, calibration data and definitions of users and projects have been stored using the Command Line Interface, Phoros can be started as a web server:

$ ./phoros --server \
>          --common-root=/some_path/where_i_put/my_raw_images/ \
>          --host=my_server --port=5432 --database=my_projects \
>          --user=database_admin --password=SeCrEt

A user can than point their browser at Phoros's URL. Example: http://localhost:8080/phoros/beautiful-cities connects to presentation project beautiful-cities (and asks for username and password).

Choose a point from the map

In the map, small yellow circles represent points of view of the available images. Pointing into an area of interest has Phoros select and display a few¹ images containing the point clicked, which on the streetmap is represented by the dark blue Phoros logo.

phoros-12.8.1.png

Point into first image

After zooming into a first image and selecting a feature of interest, epipolar lines appear in the other images which may be helpful in recognising the selected feature there.

Points selected in images are represented by large yellow circles.

Point into second image

Zooming in and selecting the same feature in a second image triggers calculation of the estimated global position. The estimated position is now shown as a cyan circle in all images and in the map. Neither estimated position accuracy nor pointing precision are bounded by pixel size.

Improve accuracy

Zooming in and pointing at the feature in some (or all) of the remaining images improves accuracy.

Store point

Finishing this point means storing it in a dedicated user point table.

Deployment

Download

Browse Phoros source code via gitweb at Github.
Browse source code of Steffen Scheller's PhoML library, which is needed by Phoros.

Get everything:

$ git clone git://github.com:trebb/phoros.git
$ # or: git clone https://github.com/trebb/phoros.git
$ cd phoros
$ git submodule init
$ git submodule update

The build process isn't perfect yet. You'll (probably) need an x86-64 Debian system with Quicklisp installed on top of SBCL.

Debian Installation Walk-Through

Install Debian; choose standard system tools and (probably) SSH server.
Install Debian packages ed, emacs, fonts-sil-gentium, g++, git, icoutils, imagemagick, proj-bin, sbcl, sbcl-source, slime, swig.

Install (as a non-root user) quicklisp:

$ wget https://beta.quicklisp.org/quicklisp.lisp
$ sbcl --load quicklisp.lisp

In SBCL, type

(quicklisp-quickstart:install)
(ql:add-to-init-file)
(quit)

Build and install Phoros:

$ git clone ... #(see above)
$ cd phoros
$ git submodule init
$ git submodule update
$ make bin-tarball
$ mkdir ~/phoros-workspace
$ cp ~/phoros/phoros_VERSION_x86_64.tar.gz ~/phoros-workspace/
$ cd ~/phoros-workspace
$ tar -xzf phoros_VERSION_x86_64.tar.gz
$ ln -s phoros_VERSION_x86_64 phoros
$ cd ~/phoros-workspace/phoros
$ ./phoros --check-dependencies
$ ./phoros --check-db --host=DB_HOST --user=DB_USER --password=SECRET --database=PHOROS_WORKSPACE_DB --aux-host=DB_HOST --aux-user=DB_USER --aux-password=SECRET --aux-database=PHOROS_WORKSPACE_DB
$ ./phoros --create-sys-tables --host=DB_HOST --user=DB_USER --password=SECRET --database=PHOROS_WORKSPACE_DB

Peruse the example scripts and the help message to learn about Phoros administration.

Building fasttrack: Install Debian package libmagickwand-dev

$ cd ~/quicklisp/local-projects
$ git clone git://github.com/TBRSS/lisp-magick-wand

In lisp-magick-wand/base.lisp change

(:unix (:or "libMagickWand.so" "libWand.so.9" "libWand.so"))

into

(:unix (:or "libMagickWand-6.Q16.so" "libMagickWand.so" "libWand.so.9" "libWand.so"))

$ make fasttrack

For use with firefox from fasttrack, set in about:config browser.link.open_newwindow.override.external to 1.

Licence

PHOROS – Photogrammetric Road Survey

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Acknowledgements

Phoros is implemented using Steel Bank Common Lisp, a Common Lisp implementation.
Communication with PostgreSQL is provided by Postmodern.
The presentation server is based on Hunchentoot.
Almost everything visible in the web browser looks as it does thanks to the OpenLayers library, interfaced by Parenscript and CL-JSON.
Without Steffen Scheller's photogrammetric library PhoML Phoros's presentation server couldn't do much beyond displaying geolocated images.
Once decoded, images are turned into something a web browser can handle by ZPNG.
Leap second information is taken from the Earth Orientation Center.
OpenStreetMap provides the map. (Other map services can be used as well, though.)

Footnotes:

The number of images can be specified during server start. Example: phoros --server --images=N ...