PARTIAL SUM FILTER AND METHOD THEREFORE

A method and apparatus for performing filtering operations on video data using a limited amount of memory is accomplished by multiplying a first coefficient value and a first input value to produce a product. A random number is generated and added to the product to produce a dithered product. The dithered product is added to an accumulated value to produce a partial sum. A truncated version of the partial sum is stored in a buffer as the new accumulated value. The multiply and add operations are repeated for a number of coefficient values and input values such that the accumulated value includes contributions from a number of different input values. The resulting accumulated value is provided as an output.