Restoration of color components in an image model

This invention relates to a method for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, the image consisting of at least one color component. In the method degradation information of each color component of the image is found and is used for obtaining a degradation function. Each color component is restored by said degradation function. The image is unprocessed image data, and the degradation information of each color component can be found by a point-spread function. The invention also relates to a device, to a module, to a system and to a computer program product and to a program module.