Haskell Photochop

CLI image editor for PPM (Portable Pixmap Format) images.

Setup

Install the libraries necessary

cabal install --lib QuickCheck
cabal install --lib random

Compile

ghc --make main.hs -o photochop  

Run

The first argument is the base image that will stay unchanged. The second argument is the name of the second image that will reflect the operations performed on the first.

To simply make a copy of an image:

./photochop lena.ppm lena2.ppm 

List of supported commands

• Flip horizontal -fh
• Flip vertical -fv
• Half height -hh
• Half width -hw
• Grey scale -gs
• Red color -rc
• Green color -gc
• Blue color -bc
• Run tests -t

To flip an image horizontally and then apply a gray scale:

./photochop lena.ppm lena2.ppm -fh -gs

Tested properties

To test the programs output I've created three difrent properties that can be tested using the QuickCheck module. Those properties are:

• Flipping an image twice gives the original image back.
• None of the pixel values are greater than the maximum value shown in the header.
• The number of total pixels should be equal to the resolution of the image.

These properties can be tested with the following command:

./photochop -t