This image processing device 1 includes a bathtub 10 which is internally filled with a propagating liquid W and in which a test object S is immersed, a measurement device 20 which comprises an element group for irradiating radiation waves into the bathtub 10 and receiving scattered radiation waves, an upper drainage detection sensor 33 which detects drainage of the propagating liquid W from the top of the bathtub 10 to outside of the bathtub 10, and a water level control module 123 which controls the water level of the propagating liquid W in the bathtub 10, wherein the water level control module 123 controls the amount of the propagating liquid W in the bathtub 10 such that before the test object S is immersed in the bathtub 10, the water level is below the top position of the bathtub 10, and performs control such that after the test object S has been immersed in the bathtub 10, the propagating liquid W is supplied into the bathtub 10 at least until drainage of the propagating liquid W is detected by the upper drainage detection sensor 33. By this means, in an automatic scan-type image processing device, it is possible with a simple configuration to image a test object with no omissions.L'invention concerne un dispositif de traitement d'image (1) comprenant une baignoire (10) qui est remplie d'un liquide de propagation (W) et dans laquelle un objet test (S) est immergé, un dispositif de mesure (20) qui comprend un groupe d'éléments pour irradier l'intérieur de la baignoire avec des ondes de rayonnement (10) et recevoir des ondes de rayonnement diffusées, un capteur de détection de drainage supérieur (33) qui détecte le drainage du liquide de propagation (W) à partir de la partie supérieure de la baignoire (10) jusqu'à l'extérieur de la baignoire (10) ； et un module de régulation de niveau d'eau (123) qui régule le niveau d'eau du liquide de propagation (W) dans la baignoire (10), le module de régulation de niveau d'eau (123) régulant la quantité de liquide de propa
