A method of processing data from an image scanner for reducing image artefacts, wherein said image scanner comprises a first image sensor arranged to scan a physical object by relative movement between the physical object and the image sensor, and to: - record a first set of lines from a first part of a physical object, the first set of lines comprising a plurality of pixels representing recorded intensities of a first colour; - record a second set of lines from the first part of the physical object, the second set of lines comprising a plurality of pixels representing recorded intensities of a second colour; and - record a third set of lines from the first part of the physical object, the third set of lines comprising a plurality of pixels representing recorded intensities of a third colour, wherein the first colour, the second colour and the third colour are different from each other; wherein the spatial locations on the physical object where the first set of lines are recorded at least partly overlap with the spatial location on the physical object where the second set of lines are recorded; and the spatial location on the physical object where the second set of lines are recorded at least partly overlap with the spatial location on the physical object where the third set of lines are recorded; wherein the method comprises generating a full colour image by the steps of: - processing the first set of lines and the second set of lines to create a first combined set of lines comprising a plurality of pixels each pixel having a value that is determined on the basis of the first set of lines and the second set of lines; processing the second set of lines and the third set of lines to create a second combined set of lines comprising a plurality of pixels each pixel having a value that is determined on the basis of the second set of lines and the third set of lines; processing the first set of lines, the second set of lines and the third set of lines to create a third combined set of lines comprising a plurality of pixels each pixel having a value that is determined on the basis of the first set of lines, the second set of lines and the third set of lines; wherein the first combined set of lines is filtered, by a low-pass filter and/or a median filter to filter out image artefacts creating a first filtered combined set of lines and to create a first filtered combined set of lines, and the second combined set of lines is filtered, by a low-pass filter and/or a median filter, to create a second filtered combined set of lines; wherein the first filtered combined set of lines and the third combined set of lines are processed together to create a first filtered set of lines; wherein the first filtered combined set of lines, the second filtered combined set of lines and the third combined set of lines are processed together to create a second filtered set of lines; wherein the first filtered combined set of lines, the second filtered combined set of lines and the third combined set of lines are processed together to create a third filtered set of lines; wherein the first filtered set of lines, the second filtered set of lines and third filtered set of lines are merged into a filtered colour set of lines comprising a plurality of pixels each pixel comprising three colour values with a first value obtained from the first filtered set of lines, a second value obtained from the second filtered set of lines and a third value obtained from the third filtered set of lines; wherein the first combined set of lines represents colour balance as the difference in intensity between the first colour and the second colour and the second combined set of lines represent colour balance as the difference in intensity between the second colour and the third colour; and wherein the third combined set of lines represents total light intensity of recorded colours. - record a first set of lines from a first part of a physical object, the first set of lines comprising a plurality of pixels representing recorded intensities of a first colour; - record a second set of lines from the first part of the physical object, the second set of lines comprising a plurality of pixels representing recorded intensities of a second colour; and - record a third set of lines from the first part of the physical object, the third set of lines comprising a plurality of pixels representing recorded intensities of a third colour, - processing the first set of lines and the second set of lines to create a first combined set of lines comprising a plurality of pixels each pixel having a value that is determined on the basis of the first set of lines and the second set of lines;