An imaging device for medical imaging includes a light source device arranged to illuminate a sample under investigation with illumination light, a detector device arranged to collect a plurality of images including at least two sample light images backscattered by the sample in different spectral ranges, and at least one marker light image originating from at least one marker substance in the sample, and a processor device adapted to process the at least two sample light images and create at least one correction component, the processor device further adapted to correct the marker light image using the at least one correction component.