1. A method of projecting text characters onto a textured surface, the method comprising: determining, from a captured image of the textured surface, a measure of the texture on the surface for a region of the textured surface over which the text characters are to be projected; selecting, based on a function of the determined measure, a glyph set, each glyph in the glyph set having visually contrasting inner and outer portions, at least one of the inner and outer portions having a width varied according to the determined measure in each of two mutually perpendicular directions, the outer portion being sized proportionally to the inner portion according to the determined measure; and projecting the text characters onto the textured surface of the region using the selected glyph set.