Test the device

How to test the device

Why test the camera

We must test the camera because the photographs analyzed by Plagio must be of good quality to reduce the possibility of having false positives.

A false positive is a positive result indicating plagiocephaly when it is not. A false negative is a negative result when plagiocephaly actually exists. False negatives are extremely rare. On the other hand, false positives can appear when the inclination between the baby's skull and the plane of the photo is too great or when the photo taken is distorted by the internal software of the device.

In this second case, one of the dimensions of the image is stretched during its display. Plagio has an internal algorithm that reduces or even eliminates this problem on most cameras. But technology is changing fast and the internal software of devices can change. So if in doubt, better check.

How to test the camera

To test the device, we will simply take a picture of a circle, analyze it. The calculated indices should reflect the fact that it is a circle. Plagio will actually calculate 3 percentages:

  • The accuracy of the device;
  • The horizontality; and
  • The user accuracy.

The accuracy of the device

It depends on the photo display software and therefore on your device. It is very close to 100%. If it is less than 99% and the other indices are correct, we advise you to change the device and we will appreciate if you can send us the references of your device by email. support@plagio.ca (indicate Test Device as the subject of the email) .

The horizontality

It assumes that the photographed sheet was on a horizontal support and that you took the photo by aligning the small red triangles on the white bars. It therefore depends almost exclusively on the skill of the user to take a photo while respecting the horizontality of the device.

The user accuracy

When analyzing the photo, you must indicate, using a pointer, the location of certain points on the photo taken. This index measures how accurately you did it during the test. if you are not close to 100, we invite you to practice by repeating the test several times.

In practice, what do we do?

Start a test

The test can be launched either from the camera function, which is used to take a picture of the baby, or from the settings menu.

Test Dialog

Test Dialog

Print the drawing to test the device

Click on print the drawing then print it following the instructions of your device.

This feature assumes you can print from your device. If this is not the case, copy and paste the following address to your computer and print the drawing.


Drawing to test the device

Drawing to test the device

Take a picture of the drawing

Place the sheet on a horizontal table, click on take a picture of the drawing and take the photo, making sure that your camera is horizontal and that the drawn circle is completely photographed.

Analyze the photo

Follow the indications which ask you to specify the location of the points A, B and C then indicate the location of the intersection of certain lines with the circle.

Viewing test results

When all points have been specified, the system displays the test results.

  • The accuracy of the device
  • The horizontality
  • The user accuracy

In fact, these results are dependent on others. If the horizontality is not good, the other indicators cannot be at 100%

View Test Result Screenshot