This app lets you open an image, and then move your cursor over the image and see horizontal bands of light corresponding to the vertical column of pixels at the location of your cursor.
I got the idea when my friend Kiba showed me a printing error one time. A large inkjet printer began printing an image, and then there was a glitch, causing the printhead to repeat the same line over and over for the remainder of the page. It was strangely beautiful! I have re-created this effect several times in Photoshop and I thought it might be neat to see the effect happen in realtime. I had also been wanting to do more GUI stuff with Python, so this seemed like a good starting place. (Normally I just do backend work with Python… And web apps with Django.)
In addition to wanting to do more GUI stuff with Python, I had also been meaning to try out GPT-4. I'm not good at mathy-coding-graphics-stuff, but I'm ok with hands-on graphics stuff, so I wrote up a detailed prompt for what I wanted the app to do and submitted it to GPT-4. Holy shit. It gave GREAT output. I responded once, then took that revised output and made only one or two very tiny edits to get this thing to do what I wanted it to do. Pretty crazy. Here's a link to the prompt and output. And some sample images of this thing in action.