[BUG] Calibration Squares not the same size as demo

[alexrockhill]

When I print out the calibration.png from here https://drive.google.com/drive/u/1/folders/18qGbHyiSJ2au9sFXScZ63EZ83PtC1-ld, it measures 28 mm instead of 25 mm in as in the toml config file. This is likely because it doesn't have the margins that are shown in the calibration clipboard videos.

[alexrockhill]

A pdf that looks correct can be downloaded from here https://calib.io/pages/camera-calibration-pattern-generator and that I measured to be correct and matches what is in the calibration video. Maybe it's better to suggest in the documentation to buy an official calibration board but there is a pdf download too.

[alexrockhill]

I made this calibration by taking an 11 x 8.5 inch canvas and pasting the image scaled to 250 x 175 mm. I haven't printed and measured to confirm yet but I think this would be better.

[lambdaloop]

Ah yes, that's a good catch. The calibration.png file just has the calibration board, but makes no guarantee about the size that you print it at. Depending on how you scale the image before you print, it could end up at any size really.

The calib.io generator is much more reliable, and I second the recommendation of using it to get files with good dimensions!

[alexrockhill]

Would it be worth a PR to make an image with the correct margins to be printed on a letter size paper? I guess it would probably need to go in the google drive though...

[lambdaloop]

I'd accept the PR that does that (it would probably go into aniposelib) , but I'm not sure if it's worth writing up the code. As you mentioned, the calib.io pattern generator already works quite well and is really customizable.

I can add a calibration pdf image in the google drive though.