Make a picture QR code
The page opens with a demo picture, a meadow at sunset drawn for this site, on the Picture tab. Drop your own photo on the box to replace it. It’s cropped to a square from the middle, so center the subject before you choose it.
Then tune it:
- Halftone or Mosaic. Halftone keeps the photo smooth with dots on top; Mosaic turns each module into a colored tile.
- Dot size (Halftone). Bigger dots read more reliably; smaller dots show more of the photo.
- Contrast. How far each dot is pushed toward dark or light. Raise it if the check says risky; lower it for a softer look.
- Module shape. On the Shape tab, halftone dots can be circles, rounded squares, diamonds, hearts and more.
Error correction is set to High automatically, because the photo makes some modules harder to read.
How it stays scannable
This is the halftone approach described by researchers Chu and colleagues in “Halftone QR Codes” (SIGGRAPH Asia 2013): a reader samples the middle of each module, so only that spot has to be clearly dark or light, and the rest of the module is free for the picture. The three corner squares and the alignment marks stay solid on light plates, because the reader uses them to find and straighten the code. Each dot takes its hue from the photo and is only made darker or lighter, so the colors stay recognizable.
Printing picture codes
Picture codes need more room than plain ones: print them at least 4 cm (1.6 in) wide, in good light, on matte paper that doesn’t glare. Keep the link short so the code has fewer, larger modules. Before a big print run, test the proof with a few different phones.