1. A method for applying a first effect to a first image, the method comprising: in a data store, receiving the first image; in the data store, receiving a first depth map indicative of first and second depths at which objects in first and second portions of the first image are disposed, respectively, relative to a camera; in a processor, applying a first function to the first depth map to generate a first mask defining a gradual transition between the first depth and the second depth; in the processor, applying a first effect to the first image such that applicability of the first effect to the first image is determined by the first mask; in the processor, generating a processed image in which the first effect is present; and on a display device, displaying the processed image.