C++ implementation of a network converter from JPG images.
The two required packages are boost::program_options and CImg.
cd build
cmake ../src
make
CImg can be tricky to import with cmake depending on your machine. The current CMakeLists.txt has been tested on MacOSX 10.13.1. However, on Ubuntu, you may need to install the following packages:
apt-get install cmake libx11-dev libjpeg-dev cimg-dev gnuplot
After compiling, the executable GRGImage should have been created in the build folder. The parameters are passed using boost::program_options so you can do
./GRGImage --help
to obtain a complete list of the parameters.
List of parameters
| Flag | Type | Description |
|---|---|---|
| --imagePath (-i) | String | Path to the JPG image |
| --outputPath (-o) | String | Path to dump the output data (add prefix of data output) |
| --number_nodes (-N) | Int | Number of nodes in the resulting network |
| --degree (-d) | Int | Maximum degree of a node (usually 3 or 4) |
| --constrast | Float | Contrast parameter between -infinity to infinity. If positive, darker pixels will have a larger weight than lighter pixels. If you have a dark background, I suggest to use negative constrats. |
| --neigh (-n) | Int | maximum number of neighbor pixels that a node can connect to (for faster convergence) |
| --help | Show the parameters list | |
| --transform | Required to transform the network | |
| --displayGray | Not implemented | |
| --CSV | Output the data in CSV format | |
| --GNU | Output the data in a Gnuplot compatible format |
Examples have been made available in the examples folder.
For the glasses example, we run:
../build/GRGImage -i ./images/glasses.jpg -o ./data/glasses -N 1000 -d 3 --contrast 3.7 --transform --CSV --GNU
1000 nodes are enough to get a sharp image.
A Gnuplot script does the plotting for us. In the past, I used matplotlib but it was very slow (2-3 minutes for plotting). I also used a d3.js script to show the images in the browser that I could release if requested.
The Gnuplot script takes some parameters
| Params | Type | Description |
|---|---|---|
| dat | String | Path to the dat file |
| o | String | Output path of the image (do not include the extension) |
| w | Int | Width of the original image (written on the dat file) |
| h | Int | Height of the original image (written on the dat file) |
| r | Float | The ratio between the output size and the original size |
| png | Int | If png=1, the image will be png |
| Int | If pdf=1, the image will be pdf | |
| lw | Float | Linewidth of the edges |
An example is
gnuplot -e "dat='./data/glasses_width1200_height748.dat'; o='./networks/glasses';w=1200;h=748;r=1;png=1;lw=1.8" ../src/GNU_plot.gpi