1. An image processing device comprising: a processor; and a memory storing computer-readable instructions that, when executed by the processor, implement: an evaluation area setting unit that sets an evaluation area whose category is to be identified in an in-vivo image; a texture component acquiring unit that acquires texture components from the evaluation area in the in-vivo image by eliminating structural components from the evaluation area in the in-vivo image; an evaluation value calculating unit that calculates an evaluation value indicating homogeneity of the texture components; and an identifying unit that identifies the category of the evaluation area on the basis of the evaluation value; wherein the evaluation value calculating unit includes a biased-evaluation-value calculating unit that calculates an evaluation value indicating homogeneity of texture components in a coordinate space, and the in-vivo image is an intra-gastrointestinal image.