The invention provides a method, data compression system, apparatus, and article of manufacture which reduce the error in transform equations in which constants are replaced by approximations. According to the invention transform constants are replaced with approximations which are a function of an integer and a floating point value. The transform equation is then performed with the integers in place of the constants. The floating point value may be applied either to the result of the equation or to the data to be processed by the transform equation before the equation is performed. Further the floating point value may be applied using a fixed precision version of the value or a fixed precision value into which the floating point value has been factored.