Design of a Hardware Efficient Approximate 4-2 Compressor for Multiplication in Image Processing

Objectives:

1. To design and implement an AO33-based approximate 4-2 compressor for multiplier architectures.
2. To reduce hardware complexity in terms of logic gate count compared to conventional exact compressors.
3. To analyze error performance using ER, NMED, and MRED metrics.
4. To implement the design in Verilog HDL and validate it through simulation in ModelSim.
5. To synthesize the proposed design on Xilinx FPGA and evaluate hardware metrics such as LUTs, slice registers, delay, and power.

Improvements:

1. Reduces logic gate count from 10 (conventional exact) to only 7 with AO33 compressor.
2. Provides lower error distance compared to AO22-based approximate compressor.
3. Achieves a better tradeoff between accuracy and hardware efficiency.
4. Improves normalized error metrics (ER, NMED, MRED) for multiplication results.
5. Demonstrates reduced LUT usage, slice register requirement, and power consumption in FPGA synthesis.