Composite image creating method, composite image creating apparatus, and computer program stored in recording medium to execute the method

Provided are a method and apparatus for creating a composite image, by which the state of a target may be effectively expressed, and a computer program stored in a recording medium to execute the method. The composite image creating method, performed by a computing apparatus, of synthesizing an input image to a target image, includes identifying information of the input image by obtaining the input image, generating a projected image based on information about a position in units of sub-pixels for the target image of the input image, by using information of the input image, generating a reduced image by reducing the projected image at a ratio corresponding to the target image, and synthesizing the reduced image to the target image.