* Please fill out this section:
** Name: Shulamith Dashevsky
** GitHub username:Shulamith

* Lab 08

* File structure:
- README.org - this file. fill out the top and use it for notes
- Makefile
- main.cpp - main driver
- funcs.h / funcs.cpp -- add your functions here.
- test.cpp - add your tests
- doctest.h - testing library

The full text of the 136 version of the lab can be found here:
https://maryash.github.io/135/labs/lab_06.html


* Overall notes:
- Write your functions in funcs.cpp
- Write your tests in test.cpp
- I will test your program by running ~make test~ then ~./test~
- Don't add .o, executable or any extraneous files to the repo
- You should commit and push your work frequently
- make sure to add sufficient tests to show that everything works
 
* Specifc changes to the lab
** Overall changes
- You do not have to download the sample image. It is in the repo and
  named *test_image.pgm*.
- The two functions in *lab-images.cpp* are already in *funcs.cpp* and
  *funcs.h* but have an additional first parameter - ~std::string
  filename~ so that you can load and save different image files
  easily. The sample code is already in ~main.cpp~. 
** Tests
- This lab does not require doctests.
** All the tasks.

For each task, write a function that creates an output image
illustrating that it works. The output filenames should be:
- *taska.pgm*
- *taskb.pgm*
- *taskc.pgm*
- etc.

Running ./main should create all these image files with no user input.
** Final note on image files
If you are using another image for any of the tasks, make sure to add
it to the repo.

Link: https://maryash.github.io/135/labs/lab_08.html