LeastAverageImage

Given a set of images, LeastAverageImage generates the least average -- the opposite of the average.

More information about the program is here: https://www.AndrewEckel.com/LeastAverageImage/

Requirements

To use LeastAverageImage, you will need

• ImageMagick: a free command line program you'll need to convert image files to and from the PPM format, the only format LeastAverageImage recognizes. Please select Install legacy utilities (e.g. convert) when installing.

You will also "pretty much need"

• A text editor that automatically color-codes INI files to make them easier to read, such as Notepad++ or Sublime Text
• A general image processing program to adjust the saturation, brightness, contrast, color balance, etc in your result images. The more variation there is your input images, the more grey-looking your raw results will be.

If you want to use images from video files as your input, you'll also need a way to convert the frames of the video into PPM images. For Windows, I can recommend VirtualDub for that. (Convert to a series of Targa files using VirtualDub, then convert those to PPM using ImageMagick. And of course, if you're converting a video file to a series of still images, you'll probably also need a separate hard drive to store them all.)

Setting up on Windows

Not compiling

Windows users can download a zip file with a 64 bit executable here: https://github.com/AndrewEckel/LeastAverageImage/releases

Compiling!

Those who want to compile the code themselves should start by cloning the entire git repo.

LeastAverageImage does not have complex dependencies, so if you have a preferred Windows C++ compiler, use that. Otherwise...

Install MinGW-w64 and add it to your Windows PATH by following the instructions here:

Setting up MinGW-w64 (just the first two sections -- Install MinGW-w64 and Test MinGW-w64)

Using the Windows command line, navigate to the project directory, where the Makefile is stored, and execute this command:

mingw32-make

Testing on Windows

After unzipping the program or compiling from the source code, navigate to the program directory using the Windows command line, and try running these two commands:

lai
lai ../input/list_mode_test.ini

The first command should create 3 PPM files in the output directory, and the second should create an additional 33.

You can use the Windows batch file in the output directory to convert the PPM files to TIF, but first you'll need to install ImageMagick and add its location to your PATH.

Compiling and testing on a Mac or other UNIX-based OS

Start by cloning the entire git repo.

Open a Terminal window in the directory that holds the Makefile, and execute this command:

make

On a Mac, if you do not have g++ and/or make installed, you will be asked if you wish to install Xcode. (Yes, you do!)

After compiling, navigate to the program directory and try running these two commands:

./lai
./lai ../input/list_mode_test.ini

The first command should create 3 PPM files in the output directory, and the second should create an additional 33.

Running LeastAverageImage

LeastAverageImage accepts one command line argument, the name of a single INI settings file. Without an argument, the program will default to ../input/settings.ini.

The included sample INI files have notes on the meaning of all the options.

LeastAverageImage is a single-threaded program. For processing multiple sets of images on a computer with "n" logical cores, you may wish to run up to n instances of LeastAverageImage at a time.

The amount of time each run takes depends on the number of input images, their dimensions, the number of difference functions included, and the highest value chosen for rankings_to_save. Remember, the area of an image is its width times its height, so if an image's dimensions are doubled, that makes it four times as big, meaning it would take LeastAverageImage four times as long to process!

For Windows users, batch files are included in the input and output folders for converting to and from PPM files using ImageMagick:

• ImagestoPPM_without_delete.bat converts all JPG/JPEG, TIF, HEIC, PNG, and WEBP files in the current folder to PPM.
• PPMtoTIF.bat converts all PPM files in the current folder to TIF and also deletes the original PPM files unless their filenames end in avg.ppm.

Sharing cool results

If you make something cool with this program, please show me, and please let others know about LeastAverageImage!