Akihisa Motoki; Thais Vargas; Lóris Lodir Zucco *; José Luiz Peixoto Neves; Felipe Dias Cario; Kenji Freire Motoki **

* Departamento de Mineralogia e Petrologia Ígnea, Universidade do Estado do Rio de Janeiro (DMPI/FGEL/CTC/UERJ). Rua São Francisco Xavier 524, Sala 4005, Bloco A, Maracanã, Rio de Janeiro, CEP 20559-900. e-mail: [email protected]
** Universidade Federal Rural do Rio de Janeiro (UFRRJ)
*** Associação Educacional Plínio Leite

The present paper shows quantitative applicability tests of macroscopic rock image direct capture by scanner without camera. Using a scanner with optical resolution 600 x 1200 dpi, interpolation 19200 dpi, the ornamental rock samples with polished surface can be scanned up to resolution 600 dpi without defocusing. In case of irregular form samples, a surface with relative relief of 6 mm can be scanned by 600 dpi, 9 mm by 400 dpi (optical definition of a hand magnifying lens), and 15 mm by 200 dpi (that of without instruments) with a good focus. On the other hand, colour definition loss due to irregular surface is more critical. To keep less than 10 % loss, the surface relief must be minor than 4 mm.