Easiest way to process /programme an image with it's pixel values as matrices in octave instead of matlab

1. install octave and octave-image in linux OS with the help of apt-get
2. start an editor to create a file with name with extension 'm' as
    your_programme.m
3. use the function ugly_matrix=imread("ugly_image filename') to grab pixel values into a matrix.
4. Do your romance and makeup with those numbers and send them back to a new image file
    using  imwrite(sexy_matrix,"new_image_filename')
5.say bye