First of all, congratulations. It looks like you found the woodworking plans you were seeking for the chairs.
If you were to use this scanner, then you would have to use Photoshop or Illustrator to reposition the pieces to make one full-sized drawing. Good luck getting a commercial shop to scan it for you unless the copyright legend on the plans clearly allow this.
If you go the photograph route, make sure you have squares or rectangles drawn on your plans. I would use those as an orthogonal reference so you can remove any keystone or skew in your image. It’s nearly impossible to photograph perfectly straight-on to get orthogonal plans; it will likely require some manipulation to get it square.
Anyway, assuming you have a non-vector file like a .jpg, you can use image trace in illustrator.
- Import
- Hit image trace dropdown in the top toolbar (there are a variety of settings)
- Then hit the expand button to create the vectors.
- You can double click the image to go into isolation mode and delete the white pieces to remove the background.
- Or use direct select tool then choose select - same - fill color.