1. A method of associating a sub-image with a contact record on a mobile device, the mobile device having a memory containing the contact record and at least one image file, the image file containing image data for rendering an image, the method comprising the steps of: receiving user selection of the at least one image file for association with the contact record; rendering the image on the user interface and overlaying a cropping shape; cropping the image in accordance with a position of the cropping shape to produce a sub-image; encoding the sub-image in accordance with a predefined image format to produce a sub-image file; storing the sub-image file in association with the contact record, wherein the step of encoding includes encoding the sub-image based upon a predefined default image encoding parameter, and wherein the step of encoding further includes determining whether the size of the sub-image file exceeds a predefined maximum file size and, if so, selecting a modified image encoding parameter corresponding to a reduced quality image and re-encoding the sub-image using the modified image encoding parameter.