Accessing the Data for Plate
The downloadable zip files
*.zip comprise all the plates from the Cdrom in a 1 or 2 byte binary image format.
The images can be imported into any GIS software (e.g. Arc/Info,Idrisi,Erdas,etc.).
For each image a header file *.hdr, a world file *.blw and an IDRISI32 documentation *.rdc file is given. The former two are required to import the *.bil images into Arc/Info via the imagegrid command.
The *.rdc file is required for use in IDRISI32, together with the included *.rst files. In some cases, the *.rdc files are also required by Arc/Info usersto identify the legend of a raster image.
Furthermore, for each plate a *.bmp and a *emf file is available. They can be viewed in suitable graphics software (e.g. Microsoft Paint, CorelDraw, etc. on the PC or XV, ghostview ... under Unix).
All images:
There are four different image sizes:
Remarks for Arc/Info
users:
Negative values in the images (such as -9999 for nodata) are imported into Arc/Info
as positve values by adding 65536. ( For example in plate01, the value 55537
should be changed to -9999 for nodata (55537 - 65536 = -9999). The setnull
command may be used to introduce nodata.)