% Define images to process
imageFileNames = {'C:\Users\asavelyev\Pictures\checkerIR.tif',...
    'C:\Users\asavelyev\Pictures\checkerIR.tif',...
    };

% Detect checkerboards in images
[imagePoints, boardSize, imagesUsed] = detectCheckerboardPoints(imageFileNames);
imageFileNames = imageFileNames(imagesUsed);

% Read the first image to obtain image size
originalImage = imread(imageFileNames{1});
[mrows, ncols, ~] = size(originalImage);

% AS: change these worldPoints to points of RGB image...
% Generate world coordinates of the corners of the squares
worldPoints = detectCheckerboardPoints('C:\Users\asavelyev\Pictures\checkerRGB.tif');

% Calibrate the camera
[cameraParams, imagesUsed, estimationErrors] = estimateCameraParameters(imagePoints, worldPoints, ...
    'EstimateSkew', false, 'EstimateTangentialDistortion', false, ...
    'NumRadialDistortionCoefficients', 2, 'WorldUnits', 'millimeters', ...
    'InitialIntrinsicMatrix', [], 'InitialRadialDistortion', [], ...
    'ImageSize', [mrows, ncols]);

% For example, you can use the calibration data to remove effects of lens distortion.
undistortedImage = undistortImage(originalImage, cameraParams);