Opencv4 Calibration Wrapper

This C wrapper exposes three functions for the explicit purpose of calibrating a new webcam using the opencv checkerboard pattern.

Usage

Print out the checkerboard pattern. Ensure the image has not been rescaled in any way (the squares of the pattern must remain square). Ideally, tape the printed pattern down onto a rigid surface like cardboard.
Use your webcam to take pictures of the pattern, held at different angles and distances to the webcam. Feed each one to supply_calibration_image(img*) Each image currently expected to be in a single-channel, CV_8UC1 format.
- Note: images supplied to this opencv wrapper are caller-owned; supply only makes a shallow copy of the image. Do not deallocate the images supplied to supply_calibration_image(img*) until after calibration is completed.
Supply at least 15 varied images (more is better).
Use calibrate() to calculate and output the camera intrinsics using the information supplied by previous calls to supply_calibration_image(img*)
Once satisfied with the calibration results, call clear_calibration_images() to clear the wrapper of all supplied images. It is now safe for the caller to free supplied images.