1. A computer-implemented method for placing a personalized text into an image to generate a natural text-rendered image comprising: determining a location and region within the image where the personalized text is to be placed; estimating a 3D geometry of a planar surface proximate to the location and region where the personalized text is to be placed; receiving a personalized text string; incorporating the personalized text string into the image to appear as if it is rendered onto the planar surface according to the estimated 3D geometry; and outputting the natural text-rendered image; wherein estimating the 3D geometry comprises: determining a first convergent line set and a second convergent line set, wherein the lines within each set are deemed to be parallel in the image; identifying a first vanishing point and a second vanishing point based at least in part upon the first and second convergent line sets; determining a field of view of the image; and determining a normal vector of the planar surface; wherein incorporating the personalized text string into the image comprises rendering the personalized text string into the determined location and region within the image using a text mask, wherein the text mask is used to modulate one or more of texture, luminance, chrominance, and transparency of the image; and wherein texture modulation comprises: utilizing a priori a plurality of images to derive sets of resolution independent basis functions that describe real world textures under a range of illumination conditions and viewpoints; fitting a texture within the determined location and region of a selected image to a linear combination of the basis functions to generate basis weights; and modulating the basis weights in real time to impose a modulation on the texture in a natural way that creates readable text within the image.