Porous polymer films of Poly-[Ethylene oxide] (PEO) are synthesized by solution casting technique using gamma irradiated: (a) PEO powder (S-series) and (b) PEO—methanol solution (L-series). Pore phase is though a defect, but form instantaneously during preparation. Optimization of the pore content, its size and distribution enable tailoring of associated properties for multifaceted applications of functional materials. The experimental pore-size distribution of the PEO films is studied using BET (Brunauer–Emmet–Teller) adsorption technique and reported as function of irradiation dose, irradiation state (S- and L-series) and polymer concentration (2 and 4 wt%). A newer computer program [PROGIMAGE-POR] is reported for determination of porosity, its size and distribution of perturbed PEO films using SEM images and correlated with that obtained from BET technique. The novelty of PROGIMAGE-POR lies in the exposure of newer or undetected pore regime in which experimental pore regime exists as a part. This method could be analyzed for mapping of porosity and average pore size. PROGIMAGE-POR bears the novelty of using image from either 2D or 3D imaging system and could be applied for intricate composite/layered system. Uniqueness of PROGIMAGE-POR lies in the exposure of newer pore regime in which experimental pores exist as a part. Theoretical analysis based on aerosity (2D-pores) and porosity (3D-pore) gives an estimate of the tortuous path of void space.