A graphics system comprises a graphics processor, a sample buffer, and a sample-to-pixel calculation unit. The graphics processor generates samples in response to received stream of graphics data. The sample buffer may be configured to store the samples. The sample-to-pixel calculation unit is programmable to generate a plurality of output pixels by filtering the rendered samples using a filter. A filter having negative lobes may be used. The graphics system computes a negativity value for a first frame. The negativity value measures an amount of pixel negativity in the first frame. In response to the negativity value being above a certain threshold, the graphics systems adjusts the filter function and/or filter support in order to reduce the negativity value for subsequent frames.