A specially fabricated high-resolution imaging technique is used to obtain atomic-resolution TEM images of single-walled carbon nanotubes and double-walled carbon nanotubes. Starting from the optical diffractions (Fourier transformations) of these TEM images, we perform an atom-resolved reconstructing operation in order to get the perfect lattice images of individual tubes. A new approach to accurately determinate tube chiralities is proposed here involving relevant analysis based on the information of tube diameters and index angles extracted from their TEM images and their optical diffractions with a help of systematic image simulations. (c) 2005 Elsevier B.V. All rights reserved.