One of my home work assignments from Nashua was to try to find out about
the resolutions used by fax machines.
The simple answer in DPI is:
res-100 (no mm equivalent)
>this resolution will be approved in Oct 97 to be used in color
transmissions only
res-200x100 (note that x-resolution is higher than y-resolution)
res-200
res-300 (no mm equivalent)
res-400
However, this is only part of the truth. Most fax machines, as well as some
printers, are natively based on lines/mm rather than DPI, which means that
we also need to be able to express values in lines/mm if we want to be exact.
Hence, we also need the following fax resolution values expressed in lines/mm:
>not that the lines/mm resolutions are not square
res-7.7x3.85
>this should be 8x3.85
res-7.7
>this should be 8x7.7
res-8x15.4 (no inch equivalent)
res-15.4
>this should be 16x15.4
There are two possible ways of doing this, either by adding this in the
attribute value for resolution, or by adding a separate attribute for the
native measuring system of the fax/printer.
In the first case we would end up with values like:
res-200x100-inch
and
res-7.7x3.85-mm
>this should be 8x3.85-mm
In the second case we would skip the last part of the resolution value and
instead have a new attribute called "printer-resolution-base" with the two
values: "metric" and "inch".
I suggest to use the second solution, which seems more extensible for the
future and which would allow a client to quickly find out what the base is
without having to read a potentially long list of resolution values.
>the second solution is also consistent with the solution used in fax
I would also encourage people in the WG that are working with metric based
printers to come up with a list of the metric values that we would need to
add for printers.
Comments? Omissions?
Carl-Uno
Carl-Uno Manros
Principal Engineer - Advanced Printing Standards - Xerox Corporation
701 S. Aviation Blvd., El Segundo, CA, M/S: ESAE-231
Phone +1-310-333 8273, Fax +1-310-333 5514
Email: manros@cp10.es.xerox.com