In an outputting method and apparatus for use with a laser beam printer or the like which handles binary data or multivalue data and can express a density of a half, the capacity of a memory provided in the printer is detected and the gradation number of multivalue image data is changed or reduced in a smaller gradation number, e.g., binary data, in accordance with the memory capacity. A part of the input multivalue image data is set in white or black binary data values. Thus, an image of a high quality can be promptly generated with high precision, and the data amount to be processed can be reduced.