All maps are created with 300 dpi.
Dimensions of the digital map (width and height) in pixel - only whole numbers are permitted.
In order to avoid having to calculate the pixel values for specific display formats, the combination of these two parameters simplifies the calculation of the size of the map bitmap on the basis of 300 dpi.
A 21cm x 29.7cm area is required for DIN-A4 in portrait format.
With 300 dpi, this results in a bitmap width and height of approx. 2,480 x 3,508 pixels.
Internally, the following applies: width = width_cm * 300 dpi / 2.54 and height = height_cm * 300 dpi / 2.54.
Metric width and height as floating point values.
Due to technical limitations (performance/memory), there is a max. number of pixels and print size.
The max. number of pixels is set to 139489119px .
This corresponds to a max. print size of A0 (118.9 x 4.1 cm) at 300 dpi
[118.9 x 84.1 cm = 46.81 x 33.11 inch = 14,043 x 9,933 px ⇒ 139,489,119]
Maps out of the max. pixelrange are rejected with an error.
Larger maps with reduced DPI
So far this is only possible with JPGs.
With the parameter low_dpi_allowed = 1 it is possible to get larger maps, but again, the max. number of pixels cannot be exceeded.
It is just adjusted the DPI value accordingly!
This allows you to specify a greater height and width, which would be rejected in the standard setting at 300 DPI.
With this parameter the max. pixel area is calculated and the JPG with correspondingly reduced DPI in the header is returned!
Request Card Size: 237.8x168.2 cm Expected Card Size at 300 dpi: 28087x19866 px Results: 14044x9933 px at 150dpi
Even with this parameter the max. print size is limited, it will not return any map with less than 150 dpi!