Abstract. The impact of using evolutionary optimised wavelet subband stuctures as allowed in JPEG2000 Part 2 in polar iris image compression is investigated. The recognition performance of two different feature extraction schemes applied to correspondingly compressed images is compared to the usage of the dyadic decomposition structure of JPEG2000 Part 1 in the compression stage. Recognition performance is significantly improved, provided that the image set used in evolutionary optimisation and actual application is identical. Generalisation to different settings (individuals, sample acquisition conditions, feature extraction techniques) is found to be low.