This article focuses on the interaction between images and observers and questions the cooperation of the image involved in a practice of visual denunciation. Constituted by scientific images, the corpus allows us to compare thermal and radioscopic images in the same practical context of airport screening. The results show how images cooperate in revelation and denunciation operations. For that we turn our attention successively to notions such as veridiction, hyper-knowledge, iconic and structural reading, camouflage and axiology.