1. An image processing device comprising: a determining unit configured to determine, in accordance with two images corresponding to temporally adjacent image data input from an external device, whether or not a field area at a time of imaging has been changed; and a suppressing unit configured to generate and output suppressed image data with an amount of visually recognizable information included in the images being suppressed by performing image processing of reducing at least one of a contrast and a chroma of the images at a time the determining unit determines that the field area at the time of imaging has been changed.