Abstract: A system including a rendering engine, a sample buffer and a filtering unit. The rendering engine is configured to render samples in response to received graphics data. The sample buffer is configured to receive and store the samples. The filtering unit is configured to read and filter the samples stored in the sample buffer to generate pixel values. The filtering unit includes a counter controller, a set of positive counters and a set of negative counter. The counter controller is configured to accumulate a histogram of exponent values of the pixel values in the positive counters and negative counters. The positive counters maintain count values for exponents of positively signed pixel values and the negative counters maintain count values for exponents of negatively signed pixel values.