1. A dotted image area detecting apparatus for detecting a dotted image area in an image on the basis of image data representing each of densities of a plurality of pixels constituting the image, comprising: setting means for setting a detecting area including a predetermined number of pixels; gray level judging means for judging which of a high gray level, a medium gray level and a low gray level is a gray level of an image in the vicinity of the detecting area on the basis of the image data; means for detecting a peak pixel in the detecting area as a peculiar point pixel if the gray level judging means judges that the gray level in the vicinity of the detecting area is the low gray level; means for detecting a dip pixel in the detecting area as a peculiar point pixel if the gray level judging means judges that the gray level in the vicinity of the detecting area is the high gray level; means for detecting the peak pixel and the dip pixel in the detecting area as a peculiar point pixel if the gray level judging means judges that the gray level in the vicinity of the detecting area is the medium gray level; and judging means for judging whether or not the detecting area set by the setting means belongs to a dotted image area on the basis of a peculiar point pixel density in the detecting area.