* fix #1665 ChAruco board topology (nearestMarkerIdx) is sensitive to scale

Add AprilTag dictionaries to be able to detect AprilTag markers. Add ArUco and AprilTag 2 citations.

Apriltag (#1570)

* doCornerRefinement to CornerRefinementMethod :: detected contours points are used to detect the corners

* some little corrections

* samples edited

* documented :)

* tabs corrected

* Docu corrections

* refinement for all candidates

* refinement for all candidates :: copy paste error corrected

* comment

* apriltag

* whitespace corrected

* corr ini

* correction :: warnings, c4244, preprocDirect, ...

* try to ignore 4244, fix 2131, add test, and ...

* try to ignore 4244

* test duplicate deleted

* corrected test, warnings

* test :: correction

* warnings

* warnings and test

* warnings

* perspective test, warning corrections

* warning a_q_t

* warning

* warning

* 3 clause BSD license

* stacksz and typo

* eliminate build warnings

- cv::fastAtan2()
- cvFloor()

* small code refactoring

* fix isfinite()

* get rid of manual calloc/free calls

* update file headers

* support custom dictionaries via python bindngs

* make markerSize and maxCorrectionBits writeable

rvecs and tvecs should be of type std::vector<cv::Vec3d> as used in the detect_markers.cpp. Otherwise an exception is thrown.

new corner refinement method :: using the contour-lines (#973)

* doCornerRefinement to CornerRefinementMethod :: detected contours points are used to detect the corners

* some little corrections

* samples edited

* documented :)

* tabs corrected

* Docu corrections

* refinement for all candidates

* refinement for all candidates :: copy paste error corrected

* comment

aruco: make public the getBoardObjectAndImagePoints function (#1108)

* Made the private static getBoardObjectAndImagePoints function public to be used for calibration.

* Switched the arguments detectedIds and detectedCorners, and objPoints and imgPoints on getBoardObjectandImagePoints function for consistency with calibrateCamera and calibrateCameraAruco functions.

* Added the flag CV_EXPORTS_W to the getBoardObjectAndImagePoints function.

* Correcting wrong type check in Aruco Board creation

* Double checking for CV_32FC1 and CV_32FC3 following @sovrasov's review

allows trading corner precision for corner quantity

also add shortcut if markers are aligned with image axes

[Aruco] Fixed the spelling of Length in Samples

replaced images to 6x6_250

Updated README

[Aruco] Updated Charuco Diamond Detection Tutorial Readme

[Aruco] Updated Charuco Board  Detection Tutorial Readme

[Aruco] Updated Aruco Tutorials  Readme

[Aruco] Updated Aruco Tutorials  Readme

Added a new line at the end of file.

Update aruco_board_detection.markdown

Update aruco_calibration.markdown

Update aruco_detection.markdown

Update charuco_detection.markdown

Update charuco_diamond_detection.markdown

Update README.md

Update charuco_detection.markdown