1. A method comprising steps of: performing one or more diagnostic operations on at least one portion of a user skin image to generate user skin image data, wherein the one or more diagnostic operations are associated with an identified skin-related application; processing the user skin image data in accordance with the identified skin-related application, wherein said processing comprises: identifying one or more sets of skin image data in a database that correspond to the user skin image data based on one or more parameters specified by the skin-related application; and determining at least one image processing filter based on the one or more sets of identified skin image data from the database; and applying the at least one image processing filter to the at least one portion of the user skin image to generate a simulated user skin image; wherein the user skin image comprises a parallel light image component and a perpendicular light image component, and the step of applying the at least one image processing filter to the at least one portion of the user skin image further comprises determining component contribution amounts for one or more of the parallel image light component and the perpendicular image light component based on at least a portion of the identified skin image data; wherein one or more of the above steps are carried out by at least one computing device comprising a processor and a memory configured to implement the at least one image processing filter; and wherein the parallel light image component comprises a specular component and first portion of an undertone component, and the perpendicular light image component comprises a second portion of the undertone component.