class Tinman.Projection.Mercator

The following figure shows the mapping between latitude/longitude values and map coordinates:

90°N 180°W     90°N 180°E
(0|0)               (w|0)     <- sample coordinates (pixel-is-point)
    \  0   1  ... w-1 /       <- sample coordinates (pixel-is-area)
    (#)--+---+---+--(#)
   0 | * | * | * | * |
     +---+---+---+---+        * := map sample (pixel-is-area)
   1 | * | * | * | * |        + := map sample (pixel-is-point)
     +---+---+---+---+
  ...| * | * | * | * |        w := raster width  (here: 4)
     +---+---+---+---+        h := raster height (here: 4)
  h-1| * | * | * | * |
    (#)--+---+---+--(#)
    /                 \
(0|h)               (w|h)     <- map coordinates (pixel-is-point)
90°S 180°W     90°S 180°E

Chapter 1.3.3.2 Popular Visualisation Pseudo Mercator,
OGP Publication 373-7-2 - Geomatics Guidance Note number 7, part 2 - July 2012,
available for download at: http://www.epsg.org.