Early prototype—scan & auto-size your own sewing patterns

Over the past few weeks, I’ve been working on a new feature: using my phone to digitize my own sewing pattern pieces. By taking a photo of each piece against a high-contrast background, the app can automatically correct perspective and scale the image to any specified dimensions. The result is a full-scale PDF you can project onto fabric, import into your vector-drawing tool, or store digitally and print at home.

For a successful scan:

• Choose a contrasting backdrop. A dark pattern on plain paper (or light pattern on dark paper) makes edge separation easy.
• Keep lighting even. Shoot near a north-facing window or under a diffuse lamp to avoid shadows.
• Frame straight-on. Aim until the paper looks like a perfect rectangle in the viewfinder—minor tilt is okay, but the closer to square, the smoother the correction.
• Leave a margin. I’ve built in an inset border in the camera overlay to help keep the pieces away from the frame edges—this avoids barrel distortion.

Upcoming work

This is still an experimental prototype, and there’s no timeline for release yet. Next, I’ll be working on:

1. Automatic edge detection, to quickly find the edges of the backing paper.
2. Size-input UI, to tell the app the real-world dimensions of the background.
3. Batch-scan mode, capturing multiple pieces and then labelling them.
4. Grid overlay in the viewfinder, to help line up each shot perfectly.

I’m hoping to make pattern scanning as fast and reliable as possible—see the video below of my first experiment.