To provide an image processor which can suppress flickering when inputting a still image easily and surely and also can suppress coloring when inputting images which have identical values for every version easily and surely.

In the image processor which has an image input means and an output image deciding means which decides an output image from an input image which is inputted from the image input means by using pseudo-random numbers, pseudo-random numbers are made to be identical series among different frames or to be identical series among different colors. As a result, an output result becomes the same as that in a previous frame when the still image is inputted. Moreover, an output result becomes the same for every color when images having the identical values for every version are inputted.