In this paper we compare two non-destructive imaging techniques based on thermal and absorptive properties of polymeric channel waveguides: scanning photothermal beam deflection- and scanning photothermal displacement-imaging. The lateral resolution of both methods is identical. There are differences in the sensitivity at a given heat source, the interpretation of the data and the data acquisition time for both methods. The photothermal deflection method is more suitable for laterally structured polymer films.