Paint by Numbers Generator

Paint-by-numbers kits split a picture into flat areas, number each area, and give you one pot of paint per number. This generator makes that kit from your own photo. It simplifies the photo, picks the 6–24 colours that represent it best, merges areas too small or too thin to paint, outlines every area and writes its colour number at the point farthest from its edges. You get a printable numbered template with a palette strip, a preview of the finished painting, the paint colours as hex and RGB codes, and a two-page PDF.

How to use this tool

1. Choose a photo; pets, landscapes and simple portraits work well.
2. Set the number of paint colours: 8–12 for beginners, up to 24 for more realistic results.
3. Pick the detail level: low makes larger areas that are easier to paint.
4. Download the template and PDF, print it and mix or buy paints that match the palette.

Formula

colours: k-means in CIELAB · area kept if size ≥ max(30, N × f) and inner distance ≥ t

N is the number of pixels at the working size (600, 900 or 1200 px on the long side) and f = 1/1500, 1/3000 or 1/6000 for low, medium and high detail. The inner distance is the chamfer distance from the area's most interior pixel to its edge; t is 3, 2.5 or 2 px. Smaller or thinner areas take the colour of the neighbour they share the longest edge with, repeated until none are left. A 3 × 3 median filter and two majority passes clean up grain first.

Example

A 3000 × 2000 photo at medium detail is worked at 900 × 600 px (540,000 pixels), so areas smaller than 540,000 ÷ 3,000 = 180 px are merged. The template is drawn at twice that size, 1800 × 1200 px, plus the palette strip, which prints on landscape A4 at about 180 dpi. With 12 colours, landscape photos in our tests gave from about 25 areas (a night sky) to about 330 (a busy scene).