Turn any Photo into a Coloring Book

We can turn our photos into a coloring book / coloring page, a so-called "Color by Number" or "Paint-by-number", online, for free. How can we do it?

First, let's look at what we are going to get. We can see the origianl photo, the produced outlines and labels (for 8 colors), and the colored page.

Color By Number

Open Photopea.com, press File - Open, and open your photo. Next, press Image - Vectorize Bitmap. We can see several options here.

• Colors - enter the number of colors, we recommend using 4 up to 20 colors
• Reduce noise - reduces the noise in your photo, it is usually better to keep it off
• Method - keep Photo for photos
• Coloring book - keep it on. It turns lots of tiny areas into several big areas
• Polygon - areas will be polygons, specify the Roughness to "simplify" the areas
• ... - choose what you want to get from your photo: the filled areas, the stroke around areas, or labels (numbers of colors and a palette). For a coloring book, disable "Fill" and enable "Stroke" and "Labels"

Once it looks as you wanted, just hit "OK" and your coloring page is ready! Now, you can export it in a PDF format for printing: File - Export As - PDF, to get a file which looks like this. You can also export it as a regular PNG image, or as a SVG - a vector file.

Number of Colors

With more colors, you can get a better image, but it will be harder to color.