Method for expanding/contracting image

PURPOSE:To provide an image expanding/contracting method capable of preventing the disappearance of thin lines and the variation of line width by correcting resampling positions and preventing positional relation from being changed by picture elements. CONSTITUTION:The magnification of expansion/contraction in the x axis direction is 1/1.3 times and three resampling picture elements corresponding to three resampling positions shown in Fig.(a) are set up so that only the center picture element is black. Since a white/black boundary changing from white to black and a reversed black/white boundary exist by scanning an image left to right in the X axis direction at the time of correcting the resampling positions, the resampling positions are moved so as to be separated from one of the boundaries only by a fixed distance Dx. In this case, the resampling positions are moved so as to be separated from the white/black boundary by the distance Dx=1/(2.rx). Consequently three resampling picture elements corresponding to three resampling positions shown in Fig.(b) are set up so that two right side picture elements are black.