1. An image processing device, comprising: an input part for inputting image data; a word extracting part for extracting a word from texts contained in said image data; a synonym obtaining part for obtaining a synonym corresponds to said word, and for associating said obtained synonym with said word; a position identifying part for identifying a display position on said image data of said word with which said synonym is associated; a layer creating part for creating an accompanying layer to add to an original layer, which is said image data containing said word, and for embedding said synonym associated with said word within a position on said accompanying layer the same as the display position identified by said position identifying part; and an output image generating part for generating output image data including said original layer containing said word and said accompanying layer within which said synonym is embedded.