An image processing device includes a processor including hardware. The processor is configured to: sequentially perform, on all at least two types of stains, an extraction process to extract a stained area due to a target stain from a single stain image of the target stain, starting from a stain having high specificity with regard to a target site; and sequentially perform a correction process, on all at least one type of second stain except for a first stain having the highest specificity among the at least two types of stains, to correct the single stain image by excluding stained areas of all stains having higher specificity than the target stain from the single stain image of the target stain, starting from the stain having the high specificity.