1. A method in a computer system, the method comprising: displaying an image on a display, wherein the image comprises image data values representing radiation emitted from an observed real world scene; receiving, as a user input signal via an input device, a user indication indicating a local area of interest in the displayed image; determining a first set of selected pixels representing the local area of interest in the displayed image based on said user input signal; determining a second set of selected pixels representing remaining pixels in said image that are excluded from said first set of selected pixels; and generating an augmented image by performing a first image processing operation on said first set of selected pixels and/or by performing a second image processing operation on said second set of selected pixels.