The invention provides an object display system for calculating a set of object data including object identification cata, vertical display position data and horizontal display position data for each of objects to be displayed and displaying the image of that object on a raster display, based on the calculated object data, the object display system having a shape generator pre-registered with the image of each object as block information represented by binary pixel data which are representative of transparent and opaque sections of the image, said shape generator being adapted to output the binary pixel data corresponding to one horizontal scan in the block of the object as transparent or opaque data for each pixel. By the shape generator judging whether each of pixels is transparent or opaque, the system can have very decreased amount of data required to perform the judgement and be of the entire simplified structure with decreased cost. Furthermore, the above judgement can be performed more rapidly.