THL Toolbox > Places & Geography > Map Folder Structure & Name Conventions
Map Folder Structure & Name Conventions
Contributor(s): Quentin Devers
Folder Structure
All the maps are to be uploaded on Blue Unix (directory: /net/quandu/thdl.org/maps/) in 5 resolutions:
- the maximum resolution available: for a scan it's 300 or 400ppi, for a map made by THL for digital publication it can be higher.
- 200ppi
- 100ppi
- 50ppi
- 25ppi
These different resolutions are stored in five folders that are named after the resolution they contain: “300+ppi”, “200ppi”, “100ppi”, “50ppi” and “25ppi”.
Beside these, maps are also stored in archive files, contained in the folder named “dls” (abbreviation of “downloads”). These archive files include for each map: the actual map, a pdf file that contains the information about the map (publisher, year,…) and another pdf file containing a translation of the legend when the map is not in English. When a map is in several sheets, all sheets are included in the archive file.
Finally, maps are stored as georectified GIS files. These files go in the “georectified” folder.
Name Standards
Each map is identified by a unique ID that is in the format M, where represents a number (ex: M7, M44, M51). When a map is published in different sheets, the number in the ID is the same for all the sheets, and they are then differentiated by the addition of letters at the end (ex: M1a, M1b, M1c; M6a, M6b).
Certain maps that are part of a specific series, like the maps of the place name indexes published in China in the 80s, can be named after the same system as for the maps published in several sheets, i.e., by retaining the same number and adjoining a letter at the end. This is however not to be followed necessarily.
When a map is published with information both on the front and the back, then both files are named after the same number in the ID. They are differentiated by the addition of “-front” or “-back” after the ID. Examples: M12a-front, M12a-back.
Finally, each image has to report its resolution in its name. The rule is to simply add “-ppi” at the end of the name of the file, where represents the resolution of the file. Examples: M15-25ppi, M15-400ppi; M12a-front-50ppi, M12a-front-200ppi.
Sometime maps have their legend on a different sheet or page. Therefore there is the need to include a scan of this separate legend as well. The rule to name the scanned legend is to name it after the map adding "-legend" after the ID (ex: M30-legend-200ppi).
For the archive files the rule is to include only the highest resolution available in it. Therefore, its name is composed by the ID of the map followed by the resolution of the highest image available. Examples: M2-400ppi, M50-300ppi, M35-600ppi. As both the front and the back of a map are included in the archive, there's no need to include “front” or “back” in the name. When a map is in several sheets, all sheets have to be included in the archive. Then the name of the archive is:
- if there are only two sheets: follow the model “M3a-M3b-400ppi” (M
a-Mb-400ppi) - if there are more than two sheets: follow the model "M1a-to-M1i-400ppi”
Finally, for the georectified GIS files, we do not indicate the resolution in the name as we work from the highest available and as the resolution is then altered by the GIS software during the georectifying process to fit the GIS needs. However we do keep the “front” and “back” indications, and we add “-georectified” at the end of the name. Exemples: “M1a-georectified”, “M24a-front-georectified”, “M35-georectified”.
Of course, all these names have to be followed by the extension of the file. As of July 2009, images are in .jpg and archives in .zip. But these format could evolve in the future.
