A system for generating image conversion data is provided. The system includes a numerator buffer storing numerator data of a conversion ratio, such as where the numerator of the ratio represents the relative current size of a set of image data and the denominator of the ratio represents the relative size of the target set of image data. A denominator buffer stores denominator data of the conversion ratio. A pixel sample control system receives the numerator data and the denominator data and generates pixel sample control data that is used to select a pixel from a pixel data stream, such as to allow a pixel dropping sequence or a pixel duplication sequence to be generated based on the values stored in the numerator buffer and the denominator buffer.