Area estimation of look-up table based fixed-point computations on the example of a real-time high dynamic range imaging system

In many FPGA-based designs, fixed-point computations can be efficiently implemented by look-up tables. However, the precision of these computations has a great influence on the hardware costs. We present two simple models for fast but precise area estimation without synthesis, that can be used for word length optimization. As an example we analyze a lookup table based implementation of a circuit for processing image combination and tone-mapping of high dynamic range (HDR) images. The results can be generalized and be applied to any problem with soft accuracy requirements.