CSC108 Assignment 2: Image Editor For this assignment, you will implement an image editor using Pillow, an image manipulation module. Before you get started, you must install Pillow. There are several ways to do this, involving Terminal and the command line (this is beyond 108 knowledge, but you’re welcome to look up guides on how to manually install Pillow). But we’re going to stick to an easy way to do it for this course: through a program called Pycharm. Instructions on getting set up are in the section below. Part 0: The Set-up So far, we have been coding using IDLE, which is a very simple coding environment. For this assignment, you will be using a slightly more advanged environment called Pycharm, and we will install Pillow, the image manipulation module, into it. Step 1: Download and install Pycharm from your computer Here: https://www.jetbrains.com/pycharm/download Download the Community Edition; you can keep the default settings during installation. Step 2: Open Pycharm and install Pillow by following the instructions in this Youtube video with strange background sounds Here: https://www.youtube.com/watch?v=jl1VAKd2BF8 (In that screen, make sure the interpreter is set to Python 3.7) Step 3: You’re all set to get started! Download the starter code from the course website. Extract the contents onto your computer – you will now have an “a2” folder on your computer Open Pycharm and when prompted to choose a project, select “Open” and then select the “a2” folder you just extracted Your a2 folder should include three files: – app_window_class.py [DO NOT MODIFY this file] – image_editing_program.py [DO NOT MODIFY this file] – image_editing_functions.py [this is your starter code for the assignment] Important Background Information and Restrctions The Pillow module that we are using has tons of features, which you are welcome to explore outside the coure. For this particular assignment however, we are placing strict restrictions on which of these features you can use. Violating these restrictions will result in a grade of 0 on the relevant function(s). What you can use from the Image module: – Image.new(mode, size, color): creates a new image (use ‘RGB’ for mode) – Image.open(filename): opens an existing image file – Image.size: returns the image size in pixels as a 2-tuple, (width, height) – Image.load(): returns a PixelAccess object of all of the image’s pixels – Image.show(): display the image represented by the Image object – Image.save(filename): saves an image – Image.close(): closes an open Image file You cannot use any other Image method, and you cannot import any other Python module, except for what we already imported for you. (But if you’re interested in exploring what else is there on your own, here is the documentation page: https://pillow.readthedocs.io/en/3.1.x/reference/ Image.html#PIL.Image.Image) From the PixelAccess module: – You can use pixels[i, j] where pixels is a PixelAccess object and i and j are the
coordinates of the pixel you are dealing with – See documentation here: https://pillow.readthedocs.io/en/3.1.x/reference/ PixelAccess.html Part 1: Adding Image Filters OK, Let’s get started! Open the file image_editing_functions.py This is the only file you will be modifying. Do NOT touch the other two files provided for you. Read through the docstring descriptions of each function and complete the code as applicable. The other two files are there for you to test out your code. To do so, you need to run image_editing_program.py But do NOT modify any of the code in this file! This file is not going to be submitted nor graded. Just use it to bring up the GUI that looks something like this: From here, you can open up the “Filter” menu at the top and play around with your filters as you complete them in image_editing_functions.py. We have already completed the “Remove Red” and “Downscale” filters for you, and added in a “Reset Image” option in this menu for you. See the demo video on the course website to see how the results of each filter should look. Note that multiple image manipulation operations can be applied to the same image, and they should build on one another. See the demo video that for examples of this: https://www.youtube.com/watch?v=5- RmguEKlPw&feature=youtu.be We also included options to “open” new files, “save” your modified files (these options can be found under the “File” menu). NOTE: A lot of these features might be slow, so you should only be testing this out with small images. We’ve included several small images for you to work with. Part 2: Adding Custom Filter(s) Optional for bonus marks up to 5% extra on the assignment For bonus marks, you can add one custom filter to your application. To do this, working in image_editing_functions.py (same file as Part 1; do NOT modify any of the other files that we gave you): 1. create a new function at the bottom of the file (before the COMMANDS dictionary, but after all the function skeletons we provided for you) that is related to your filter’s functionality, with a type contract and a good docstring description 2. write code in this new function’s body to apply your filter to a given image and return the updated image 3. in the COMMANDS dictionary which should be at the very bottom of your image_editing_functions.py file, add a new key that is the label for the filter (as a string) and the associated value should be the name of the newly added function that applies this filter to an image and returns the updated image For this part, you will be graded on creativity and effort. A very simple addition could be to remove green or remove blue … these will not be worth many marks because we already gave you remove_red, which is too similar! So, these would be pretty boring and easy to implement custom filters. Try to think of something a little more interesting and unique. 🙂 Adding just one filter is good enough to earn you the full marks for this part, as long as your code is creative, shows effort, and actually works! But if you have more ideas, you are welcome to add in more. Have fun with it! Remember to add all your custom filter functions after all the base functions from Part 1, to make it easy for us to spot them when we are evaluating your code. You may also hand in a text file enhancements.txt to describe your ideas for the custom filters, or if there is anything you want us to know about them. This time, this file is optional because it should be fairly easy to find out what changes you made to the program, without needing this file. Guidelines/Cleanup: Before handing in your code, make sure to do the following: 1. Check that you have followed our style guide 2. You will not only be marked for correctness, but also for design. This means your code should be as clean and simple as possible. Go over your functions to check for cleanliness and simplicity in your code. Use helper functions whenever they would be appropriate. 3. Remove any code you added just for testing, such as print function calls. 4. Remove any pass statement where you have added the necessary code. 5. Double check that all your function code matches the given docstrings, including the type contracts; for example, if the docstring type contract says to return an int, your function must return an int, or else it will be graded 0 for correctness. Note: You should never change the name of any function given in the starter code, as doing so will make our auto-grader fail. 6. For part 2: Check your docstrings to make sure they are precise and complete, including a type contract and good, straightforward description. 7. Make sure your code runs (try it out on someone else’s computer if you can, not just your own)! If you have some attempts that you want to get partial marks for, great. Please submit your attempts; however, if your incomplete/incorrect attempts cause your code to crash then please comment out invalid code before handing it in. We must be able to run your program in order for the au
tograder to give you marks for other functions that might work. What you will be handing in: Submit only the following file on MarkUs by the deadline on the course website: 1. image_editing_functions.py If you have any extra files you need for your part2 bonus filter to work, you may hand those in as well. Again, please make sure your code is cleaned up and that your main program runs! If your program crashes as soon as we run it, our autograder will give you a 0 on all your functions, even ones that might work! If you want to leave in some code that did not work, but shows the effort you put into trying to complete it, you can do so for possible, partial marks BUT COMMENT IT OUT, so it doesn’t crash your entire program! Assessment: Your mark will be based on both correctness as well as cleanliness of code (following the Python style guidelines, following design recipe, avoiding repetitive code – using helper functions, etc.).
