Ahmed Naqvi, Syed Faraz, et al. “An Edge Based Technique for Spatially Varying Defocus Blur Estimation of Image Using Gradient Magnitudes - Simulation & Result”. International Journal of Computer Sciences and Engineering, vol. 7, no. 10, Oct. 2019, pp. 81-89, doi:10.26438/ijcse/v7i10.8189.