1. An image processing apparatus comprising: a recording rate determining section for determining a recording rate of each of a plurality of dot types having different densities per unit area from each other according to an input value comprising a multi-gradation image data, the input value being quantized for forming a dot of the plurality of dot types; a dot formation judging section for judging whether the dot is to be formed on each pixel based on a total recording rate which is a sum total of each recording rate of the plurality of dot types, determined by the recording rate determining section; and a dot selecting section for selecting a dot type among the plurality of dot types having different densities per unit area from each other, to a pixel on which the dot formation judging section judges that the dot is to be formed, wherein an image is formed according to an arrangement distribution of the dot.