Implementation of image fusion for guided filtering from article [1]

guidedfilter function is not provided but can be found on http://xudongkang.weebly.com/
jbfilter2 function (joint bilateral filtering) can be found at https://fr.mathworks.com/matlabcentral/fileexchange/27468-joint-bilateral-filter

[1] Shutao Li, Xudong Kang and Jianwen Hu, "Image fusion with guided filtering", IEEE Transactions on Image Processing, vol. 22, no. 7, pp. 2864-2875, July, 2013