1. An image processing apparatus comprising: input means for inputting multi-level image data; quantizing means for quantizing the multi-level image data and generating N-level (N.times.3) image data; and converting means for converting the N-level image data, wherein the N-level image data corresponds to dot patterns in accordance with a level of the N-level image data, and said converting means converts the N-level image data based on an arrangement of the dot pattern, and wherein said converting means chances the dot pattern in accordance with an arrangement of the N-level image data.