This paper presents an extremely fast and very low complex energy efficient image compression scheme for resource constrained, low powered devices in real time applications. The proposed Optimal Zonal 2×2 BinDCT is unique since it directly extracts and codes the DC Coefficient and the first three AC coefficients of an 8×8 image block using only shift-and-add operations. It is specifically designed for the resource constrained image sensor wireless networks requiring very low bitrates and is investigated in terms of image quality, entropy, processing time and overall energy consumption. Experiments are performed using the Atmel ATmega128 processor to measure the computation time and the resultant energy savings. Simulation results show that the proposed algorithm is extremely simple, fast and consumes only 4% of computation energy needed by Independent JPEG Group IJG version and thus prolongs the system lifetime. © 2013 Elsevier B.V.