Google Compatibility Test Suite (CTS) User Manual - Manual (Page 17)

Setting the target width
Measure the distance between the solid lines on the target pattern in centimeters to
account for printing inaccuracies (~38 cm).
1. Start the calibration application.
2. Press the setup button and select “Marker distance” to enter the distance.
3. Measure and enter the distance to the target pattern (~100 cm).
4. Press the back button to return to the calibration preview.
Calibration process
Verify that the device and target are placed as shown in the figure and the correct
distances have been entered into the setup dialog.
The preview will display the image with a vertical line overlaid onto it. This line
should align with the center line of the target pattern. The transparent grid can be
used with the other vertical lines to ensure that the optical axis is orthogonal to the
target.
● Select an image resolution to test from the selector at the bottom left.
● Tap the screen to take a photo and enter the calibration mode (described
below).
● Hit the back button and repeat for all supported image resolutions.
Calibration test (per resolution)
In the calibration mode, the photo will be displayed with two vertical lines overlaid
onto the image.
These lines should align with the vertical lines on the target pattern within a few
pixels. If they do not, then the reported field of view for that mode is inaccurate
(assuming the setup is correct).
Adjust the slider at the bottom of the screen until the overlay aligns with the target
pattern as closely as possible. The displayed field of view will be a close
approximation to the correct value when the overlay and the target pattern image are
aligned. The reported field of view should be within +/-1 degree of the calibration
value.
5.4. Exporting test reports
● After all tests are completed, tap the MENU button from the CTS Verifier home
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