PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 2018-06-29 NOTE = "EXTRINFO.TXT describes the files in the EXTRAS directory of this volume" END_OBJECT = TEXT END The EXTRAS directory contains files which facilitate the use of the LROC NAC and WAC data, but that are not actually required for the use or understanding of those data. The BROWSE directory contains browse images for the NAC and WAC images in the published volume. The browse images are TIFF formated graphic file that are internally tiled with 256x256 tiles. The layers are constructed by halving the resolution of the previous layer (starting with full resolution as the first layer) until a layer is created with only 1 tile. The browse image is created using the VIPS software (http://sourceforge.net/projects/vips). The HISTOGRAM directory contains histogram plots for the NAC and WAC images in the published volume. The histogram is a simple XY plot generated using the NetPBM pgmhist program (http://netpbm.sourceforge.net) showing pixel count for specific DN values. Histogram plots for WAC color (7 band) images do not discriminate between the bands. The BROWSE and HISTOGRAM directories are organized into subdirectories representing the year and day of year for an image acquisition.