We present the B-band surface photometry of 19 early-type galaxies of the Virgo cluster, and of 28 galaxies of the same morphological type belonging to the Fornax clusters, obtained through the `global mapping' technique which couples CCD and photographic plates. Taking into account 33 galaxies already studied by Caon et al. (1990) with the same methodology, the Virgo sample of early-type galaxies is now 80% complete down to B_T_=14. The Fornax sample is 95% complete down to B_T_=15. The geometric and photometric properties of the total sample of 80 galaxies are derived measuring accurate light profiles, ellipticities, position angles and Fourier coefficients of the isophotes. The main sources of errors of the `global mapping' procedure are reviewed and the effects of seeing discussed. Global galaxian parameters such as total luminosity, effective radius, and effective surface brightness, are computed for the whole sample in a homogeneous way. Our goal is to create an unbiased set of data to be used for investigating the process of galaxy formation and evolution.