Show HN: Reduction Blockprint Planner/Simulator

I’ll start this by saying I am not a programmer. As such, I’ve used Claude Code to do most of the coding, so I expect some issues on the vibe coding front.

As a hobby I do block printing - usually linoleum, sometimes I 3-d print plates to make prints. One of the techniques that I use to make multi-colored prints is called reduction printing (https://en.wikipedia.org/wiki/Printmaking). Instead of carving multiple blocks, one for each color, you use the same block, and with each layer you leave behind in the negative space some of the previous color(s). It is sometimes difficult for me to visualize what this should look like, so I created this simulator/planner to help.

The workflow is: 1. Upload an image 2. Crop image (free or to an aspect ratio for your block). I think you need to at least acknowledge the crop even if using the whole image. 3. Quantize/posterize the image to a set number of colors. 4. Optionally flip the image so when it is relief printed it turns back the right way 5. Generate the layers 6. Export the layers as individual images. 7. Generate a gif that simulates what the printed image would look like one layer at a time.

This was originally made with server-side image processing in python (what i feel sort of comfortable with), but I figured I may as well try to get this all client-side in the browser so it can be deployed as a static site to Cloudflare Pages or Github Pages. After getting it working, Claude planned and executed the migration. This now runs totally in the browser. I was surprised that the projects persist between sessions, but they do.

For me this was as much an exercise in exploring what can be done with a bit of planning and some vibe coding as it is to help me with my hobby.

Any feedback is appreciated.

Github: https://github.com/greghirson/reduction_planner

I will eventually write a post about it at https://greg.hirson.xyz, where you can also see some of the block prints I’ve made (reduction or otherwise).