1. An image inspection apparatus for checking an image printed on a recording medium comprising: a reference pixel obtaining unit configured to generate a reference image from image data configuring the image and obtain a first pixel value from the reference image; a print pixel obtaining unit configured to extract an image printed area containing the recording medium on which the image to be checked is printed, and obtain a second pixel value from the image to be checked; an offset processing unit configured to add a non-image-printed area so as to surround the reference image on the periphery of the reference image; and an image checking unit configured to compute a difference between the first image pixel value and the second image pixel value and detect an error when the difference is higher than a predetermined threshold value, wherein the non-image-printed area contains a third pixel value that is significantly different from either the first pixel value or the second pixel value, and the image checking unit suspends a determination whether or not there is an error in the image printed area associated with the non-image-printed area.