Improve documentation concerning estimated pose about apriltag HOT 5 CLOSED

You can send a PR which adds the comments to the apriltag_pose_t struct anyway. Not sure about the wiki. Someone else has to add those changes as you cannot send a PR to the wiki git (https://github.com/AprilRobotics/apriltag.wiki.git).

Apart from this, I find the two figures confusing. First of all, the coordinate axis colours do not match. The X, Y, Z axes should correspond to the colours red, green, blue. We are also using the OpenCV convention with Z pointing forwards and X and Y like in the image frame. Then, showing a figure with multiple tags on a cube with a single coordinate frame is confusing. I would propose showing a single tag with the same orientation as in the example tags in the apriltag-imgs repo with only a single coordinate frame.

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@christian-rauch

• yes I can create a PR for the comment.
• The X, Y, Z axes should correspond to the colors red, green, blue. lol my bad this is what I wanted to respect (XYZ => RGB) but I totally failed for the camera, good catch :)
• multiple tags on a cube yes I did not found a flat and rotated April.
  I'll redo

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Here second attempt with pull request.

If the wiki is too problematic, what about creating a pull request to add markdown files back to the doc folder ?

AprilTag-User-Guide(1).md

coord.drawio.txt

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Are you sure this is the correct camera coordinate system? This looks like the OpenGL camera (projection) coordinate system. Shouldn't Z point forward and Y down?

The rest is just nitpicking: The tag looks like you just cropped it out of the box from the image above. This is clearly visible :-) and does not look nice. Also, the coordinate axes' colours are desaturated and do not have a nice contrast against the tag image. E.g. the green and blue look similar against the tag background.

In any case, you will need @mkrogius to update the wiki as, AFAIK, you cannot open a PR for the wiki. Alternatively, we could move the documentation directly to the repo, e.g. inside a doc folder, and link it from the main README.md on the repo start page. This will also make it easier discoverable.

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Arf, yes I c... again the axis. I definitely do not know to draw :( The coordinate system has the origin at the camera center. The z-axis points from the camera center out the camera lens. Ok so tag and camera have the same coordinate? Thanks for your patience. I fix my previous comment and close this ticket to let a better drawer make a better figure.

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