CDI, CDi, or CD-i may refer to: Science and technology Carbonyldiimidazole, peptide coupling agent CD-i or Compact Disc Interactive, interactive multimedia CD player and format developed and marketed by Royal Philips Electronics, N.V. Coherent diffraction imaging, lensless nanoscale imaging technique Collector Diffusion Isolation, technique used in semiconductor device fabrication Color Discrimination Index, a measure relevant for appraisal of color rendering Conditioned Diphase, method of di… (More on Cdi)