A method and system of determining fiber diameter distribution of a fibrous media is disclosed. The method includes providing at least one digital image representative of the fibrous media, pre-processing the images, binarizing the images, generating virtual lines on the image, solving for fiber fringe points on each of generated line, solving for fiber center points as a mean of the fringe points, generating and growing measurement circles about the fiber center points, repositioning circles and center points to avoid fiber intersections, resizing the repositioned measurement circles to intersect the opposing fringes, and calculating fiber diameters and fiber spacing.