Fuente: WIPO "varroa" The invention relates to a method of calculating the deviation relation of a population registered on an image comprising the following method steps; i.) identify the objects in the image, ii.) count the number of identified objects, iii.) identify abnormalities in said image, iv.) identify objects with abnormalities in said image, v.) count the number of objects with abnormalities, vi.) calculate the relation of objects with abnormalities to all objects. The invention further relates to computer program comprising program code, which, when said program code is executed on a computer, causes said computer to perform the method of calculating the deviation relation of a population registered on an image. The invention further relates to a handheld computer device, and to a system.