The traditional image encryption schemes, implementing fully layered encryption, seem to be undesirable in situations where there exists high data rate with limited bandwidth. A fully layered image encryption scheme first scrambles the image (to destroy the high correlation between neighbouring pixels) then encrypts it, resulting in a high computational overhead. In recent times, partial or selective encryption schemes are gaining popularity especially in situations demanding constrained communication such as mobile communications with limited computational power. In this paper, the performance of a chaos based partial image encryption scheme is evaluated in terms of a set of evaluation criteria. Exhaustive experimental simulation is performed to analyse the efficacy of the encryption scheme. © Springer Nature Singapore Pte Ltd. 2017.