1. A method for compensating for a spatial non-uniformity in an image rendering device, the method comprising: predetermining a spatially dependent compensating tone reproduction curve for the rendering device; receiving a halftoned image including a plurality of respective halftone pixels having respective halftone pixel values, the respective halftone pixels being associated with respective halftone pixel positions in the image; and determining respective compensated values for the respective halftone pixels based on the respective halftone pixel positions, the spatially dependent compensating tone reproduction curve and associated respective halftone pixel values.