1. An image-processing device comprising: a storage unit which stores font data of each character, comprising a character code specifying the character and form data representing form of the character specified by the character code, with the form data comprising at least standard form data in each of prescribed fonts; a judgment unit which judges whether each character should be expressed in boldface type or not based on style information comprised in a drawing instruction in response to reception of the drawing instruction which comprises a character code specifying a character, font information specifying a font type, font size information specifying a font size, and the style information at least specifying whether or not to express the character in boldface type; a boldface data-generating unit which generates boldface form data of the character in response to the judgment unit judging that the character should be expressed in boldface type, by reading out the standard form data of the character corresponding to the font type specified by the font information comprised in the drawing instruction from the storage unit, determining shift amounts in horizontal and vertical directions based on the font size information comprised in the drawing instruction, and repeating drawing of the standard form data while shifting the standard form data in the horizontal and vertical directions according to the determined shift amounts; and an output unit which converts form data such as the boldface form data generated by the boldface data-generating unit into image-formation data and outputs the image-formation data to an image-formation device which forms an image according to the image-formation data, wherein the boldface data-generating unit comprising a shift amount adjustment unit which adjusts the shift amounts in the horizontal and vertical directions so that result of the repetition of the drawing of each dot of the standard form data while shifting the standard form data in the horizontal and vertical directions according to the shift amounts will lack one or more dots at each of four corners, and wherein the boldface data-generating unit generates the boldface form data by repeating the drawing of the standard form data according to the shift amounts in the horizontal and vertical directions adjusted by the shift amount adjustment unit.