Turn any Photo into a Coloring Book

We can turn our photos into a coloring book / coloring page, a so-called "Color 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, I usually 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.