  For many years, the image databases used in steganalysis have been relatively
small, i.e. about ten thousand images. This limits the diversity of images and
thus prevents large-scale analysis of steganalysis algorithms.
  In this paper, we describe a large JPEG database composed of 2 million colour
and grey-scale images. This database, named LSSD for Large Scale Steganalysis
Database, was obtained thanks to the intensive use of \enquote{controlled}
development procedures. LSSD has been made publicly available, and we aspire it
could be used by the steganalysis community for large-scale experiments.
  We introduce the pipeline used for building various image database versions.
We detail the general methodology that can be used to redevelop the entire
database and increase even more the diversity. We also discuss computational
cost and storage cost in order to develop images.
