1. A computer-implemented method for generating non-destructive automatic face-aware vignettes, the method comprising: receiving a request to generate a vignette for an image that includes one or more salient objects displayed in the image; determining an aspect ratio of the image and at least one boundary that encloses the one or more salient objects displayed in the image; automatically modifying one or more parameters of the vignette based on the at least one boundary to customize the vignette based on the one or more salient objects displayed in the image; determining an eccentricity of the vignette based on the aspect ratio, the eccentricity representing an amount that the vignette deviates from being circular; determining an excess eccentricity representing an additional amount by which the eccentricity exceeds a recommended amount of eccentricity associated with the aspect ratio; automatically modifying one or more additional parameters of the vignette based on the excess eccentricity; and generating a customized version of the vignette for the image for display via a display device, the customized version of the vignette being generated based on the one or more modified parameters and the one or more additional modified parameters.