This device is an open-source approach to scanning flat surfaces. The frame is simply placed on top of the surface to scan, and a computer vision software analyzes the picture to extract a rectified picture with real dimensions (pixels/unit).
This device is an open-source approach to scanning flat surfaces. The frame is simply placed on top of the surface to scan, and a computer vision software analyzes the picture to extract a rectified picture with real dimensions (pixels/unit).
<imgsrc="img/comparison.jpg"width=90%></img>
<imgsrc="img/comparison.jpg"width=70%></img>
This project is inspired by the [Shaper Trace](https://www.shapertools.com/en-us/trace), but offers an open source interface and lets users scan color images, not just vectors.
This project is inspired by the [Shaper Trace](https://www.shapertools.com/en-us/trace), but offers an open source interface and lets users scan color images, not just vectors.
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@@ -30,21 +30,21 @@ If you have access to digital fabrication tools, the most straightforward way to
The first step is to weed the vinyl in place:
The first step is to weed the vinyl in place:

<imgsrc="img/vinyl1.jpg"width=50%></img>
The result is then stuck onto transfer tape and laid flat:
The result is then stuck onto transfer tape and laid flat:

<imgsrc="img/vinyl2.jpg"width=50%></img>
After joining to the frame, the transfer is peeled off, revealing the finished frame:
After joining to the frame, the transfer is peeled off, revealing the finished frame:

<imgsrc="img/vinyl3.jpg"width=50%></img>
### Inkjet printing
### Inkjet printing
Alternatively, you can print the design of the frame using an inkjet printer, then glue it to a thin piece of cardboard:
Alternatively, you can print the design of the frame using an inkjet printer, then glue it to a thin piece of cardboard:

<imgsrc="img/cardboard.jpg"width=50%></img>
The small frame is designed to be printable on an A4 page (or letter), and the medium frame fits on an A3 page.
The small frame is designed to be printable on an A4 page (or letter), and the medium frame fits on an A3 page.
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@@ -52,20 +52,20 @@ The small frame is designed to be printable on an A4 page (or letter), and the m
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@@ -52,20 +52,20 @@ The small frame is designed to be printable on an A4 page (or letter), and the m
To quantify the accuracy of the scanning, a 25mm calibration grid was built:
To quantify the accuracy of the scanning, a 25mm calibration grid was built:

<imgsrc="img/grid.jpg"width=70%></img>
Here is the image used for analysis, showing the detected features (aruco markers in blue, corners in red):
Here is the image used for analysis, showing the detected features (aruco markers in blue, corners in red):

<imgsrc="img/features.jpg"width=70%></img>
Here is the extracted image:
Here is the extracted image:

<imgsrc="img/result.jpg"width=70%></img>
The grid feature points are automatically extracted:
The grid feature points are automatically extracted:

<imgsrc="img/grid_features.jpg"width=70%></img>
Finally, the distance between neighboring grid points is measured, revealing the accuracy of the scanning process. Here is a comparison of all frames, including the Shaper Trace, showing improved accuracy and less variance:
Finally, the distance between neighboring grid points is measured, revealing the accuracy of the scanning process. Here is a comparison of all frames, including the Shaper Trace, showing improved accuracy and less variance: