If a GitHub repository is a Jupyter Notebook that explains why a histogram is equalized step-by-step, that is a tutorial, not a cheat sheet. Professors generally allow referencing tutorials.
Tavneetsingh01's Python Practicals covers core tasks like contrast stretching, gray level slicing, and image negatives. Table of Contents (Core Problem Areas) digital image processing 3rd edition solution github
(MATLAB) : While strictly for the "Digital Image Processing Using MATLAB" companion book, these functions are essential for anyone using the Gonzalez/Woods curriculum. What These Solutions Cover If a GitHub repository is a Jupyter Notebook