[Qgis-user] Re: [Qgis-developer] Request for Enhancement: PDF export for post-processing

Tyler Mitchell (OSGeo) tmitchell at osgeo.org
Fri Mar 5 16:09:51 EST 2010


Arg, forward to hit send last night..  Dane's already followed up, oh
well...


>From another angle, I exported using Quantumnik (mapnik plugin) into PDF
and it worked well.  Text has issues there as well, but Dane can speak
more about it than I can.  This feature depends on Cairo library being
improved apparently.

Tyler

Milo van der Linden wrote:
> I just found out that the main bulk in manual labour is repositioning
> text. It turns out that any export from Qt creates text as outlines,
> whatever program you use. A quick intermezzo on the #qt irc channel at
> freenode learned that Qt is simply *not* capable of rendering text as text.
> 
> This would be the first thing that my contact would really like to see
> fixed. So; to limit the bounds of the question;
> 
> What would be the effort to export text as text? Could it be done at all
> given that Qt doesn't support it?
> 
> Kind regards,
> 
> Milo van der Linden
> 
> 
> Alex Mandel wrote:
>> As I mentioned in IRC here it the thread about the same topic leading up
>> to the november hackfest.
>> http://n2.nabble.com/SVG-export-td3792011.html#a3792011
>>
>> You can see it in the topic list too
>> http://www.qgis.org/wiki/2._QGIS_Hackfest_in_Vienna_2009
>>
>> In the end it seems like mapsever, osm and a bunch of other projects are
>> stuck because there isn't a good rendering toolkit, or we aren't making
>> use of the current ones. So we have the option to try and patch Qt svg
>> support to maybe solve it or to hunt around at other svg rendering
>> libraries and try to bring those into the fold, not sure what
>> openoffice, scribus or inkscape use but those seem like good places to
>> start asking.
>>
>> I guess the question is do we know a programmer who could solve this
>> issue if we shuffled money their way from Milo's source?
>>
>> Thanks,
>> Alex
>>
>> Milo van der Linden wrote:
>>  
>>> Hello Tyler!
>>>
>>> Thank you for sharing this. Indeed as described in the article on the
>>> wiki; the main point is: Don't build advanced cartographic composition
>>> functionality into any of the GIS products that are on the OSGeo stack.
>>> Less is more.
>>>
>>> If the GIS(es) could export to PDF with
>>> * PLAIN vector-work; ordered in PDF layers
>>> * Text as text and not as letter-contours (perhaps even with standard
>>> font embedded)
>>> * Symbol nodes as dots, ordered per layer based upon attributes
>>>
>>> My contact would be well served!
>>>
>>> Even putting effort in creating advanced symbology would be to much,
>>> use-it will want to change even that in his desktop publishing
>>> environment, so a simple node and the fact the node is on a certain pdf
>>> layer would be enough information for him to transform all the nodes
>>> into the symbology he wants.
>>>
>>> Right now he has days of work to create a single map of a city
>>> post-processing the GIS data (mainly cleansing) and then the
>>> cartographic work starts. If we could remove the cleaning job, it would
>>> be a win of 2 to 6 days per city map which would be excelent!
>>>
>>> Tyler Mitchell (OSGeo) wrote:
>>>    
>>>> Hi Milo, I just missed you in IRC.  I'm not a QGIS developer but I've
>>>> been trying to clarify an idea a few folks started a couple years back.
>>>> Specifically, establishing a standard way of doing high quality,
>>>> vector/raster output which would do pretty much what you are
>>>> describing.
>>>>
>>>> Standing back as a user, I think many projects have this challenge and
>>>> could work together if the approach was abstracted and some common
>>>> underlying tools agreed on or tested.
>>>>
>>>> Without writing it all out, my thoughts are here and might be
>>>> interesting to you.  Dane's work on Quantumnik are encouraging and, in
>>>> my little world, are pushing the envelope of what's described here too:
>>>>
>>>> http://wiki.osgeo.org/wiki/OSGeo_Cartographic_Library  See the first
>>>> two
>>>> sections for clarity.  The rest is a brainstorm that's not well
>>>> organised.
>>>>
>>>>
>>>>
>>>> Milo van der Linden wrote:
>>>>  
>>>>      
>>>>> Hello People!
>>>>> I have a question.
>>>>>
>>>>> This summer I met someone of use-it http://www.use-it.be/ belgium
>>>>> at the
>>>>> OpenStreetMap State of the Map.
>>>>>
>>>>> Use-IT creates free paper maps for youth-hostels targeting a specific
>>>>> audience. Currently they are using the tool chain:
>>>>> OpenStreetMap website -> export svg -> import in Illustrator ->
>>>>> lots and
>>>>> lots of manual labour and finally produce eye candy like this:
>>>>> http://www.use-it.be/_files/inlineuploads/pages/MAP_O_Brussels.pdf
>>>>>
>>>>> Recently, the contact reached out to me. He could not find a solution
>>>>> within
>>>>> the OpenStreetMap community or it's related technology partners. Now
>>>>> I am
>>>>> helping him out looking at new ways to speed up their labour process.
>>>>>
>>>>> I am investigating the qGIS pdf export and it looks promising in
>>>>> combination
>>>>> with the OpenStreetMap plugin but texts come out as letter-outlines
>>>>> instead
>>>>> of fonts and the PDF layers structure is hard to work with. I would
>>>>> like to
>>>>> know if the developers of the layouter/export would be interested in
>>>>> about 2
>>>>> weeks of work to enhance the layout manager to something that creates
>>>>> pdf
>>>>> that is perfectly fit for post-processing.
>>>>>
>>>>> *****************1. PROCESSING PROBLEM*
>>>>>  This remains almost impossible - only supercomputers are able to
>>>>>  deliver an svg-file of a city of reasonable size, and even that is
>>>>>  still only a 50% shot. It took us a full night to render a city, and
>>>>>  were able to get there only with one of about ten available
>>>>>  xml-rulesheets (called z12). How could this be tackled?
>>>>>
>>>>> This one is tackled with the OSM plugin in combination with the PDF
>>>>> export.
>>>>> As far as I can see, the way osm data is presented in qGIS is
>>>>> simplified,
>>>>> but this is good! We don't need shading, outlines and a whole lot of
>>>>> fencies
>>>>> in this fase. The eye-candy will be created in Illustrator. So, as
>>>>> far as I
>>>>> can see; qGIS tackles this issue.
>>>>>
>>>>> *****************2. LAYER PROBLEM*
>>>>>  The svg does not contain separate layers with a clear content (like
>>>>>  'parks', 'roads', 'rivers'). Only the layers 'Map' and 'Map
>>>>>  Decoration' appear, but all the information is thrown together in
>>>>>  the layer 'Map'. You say it's a matter of someone finding the time
>>>>>  to improve this - but who is the best person to address?
>>>>>
>>>>> In the OpenStreetMap data format, there are basically 3 layers:
>>>>> points,
>>>>> lines and polygons. The "real" layering is organised in attributes
>>>>> called
>>>>> tags. To be more generic; It would be good to push elements to a pdf
>>>>> layer
>>>>> based upon grouping by attribute. In case of openstreetmap data, it
>>>>> would
>>>>> mean applying some rules to strip out the tags into the required
>>>>> attributes
>>>>> and then in the layout manager tell the pdf export to "group by
>>>>> attribute
>>>>> column A"
>>>>>
>>>>>
>>>>> *****************3. TYPOGRAPHICAL PROBLEM*
>>>>>  Layouters prefer to work with Adobe Illustrator to make maps. It's
>>>>>  what they know best, and Inkscape is just not as good yet.
>>>>>  Osmarender renders svg files. It is possible to open an svg-file in
>>>>>  Illustrator, but then you get typographical problems, illustrated
>>>>>  below. Our question: could Osmarender be made to deliver an eps-file
>>>>>  (always works in Inkscape AND Illustrator) instead of an svg?
>>>>>
>>>>>  This is what happened to a small part of Antwerp (Belgium):
>>>>>
>>>>>  SVG IN INKSCAPE
>>>>>   > opens fine
>>>>>   > text is fully editable
>>>>>   > see image 'svg_inkscape'
>>>>>
>>>>>  SVG IN ILLUSTRATOR
>>>>>   > opens upside down and with mistakes
>>>>>   > text is still editable as text (so it's not flattened), but does
>>>>>  not appear on a horizontal path in the street. Furthermore, every
>>>>>  letter is on a different path, so it's impossible to select an
>>>>>  entire word.
>>>>>   > see images 'svg_illustrator' and 'svg_illustrator_detail'
>>>>>
>>>>>  SVG SAVED AS EPS IN INKSCAPE AND THEN OPENED IN ILLUSTRATOR
>>>>>   > opens fine
>>>>>   > text is flattened and not editable anymore, and therefore useless
>>>>>  for layout
>>>>>   > see images 'eps_illustrator' and 'eps_illustrator_detail'
>>>>>
>>>>> **************
>>>>> Again; as far as I can see, it is qGIS to the rescue! The whole
>>>>> process of
>>>>> going from svg through inkscape to Adobe Illustrator is greatly
>>>>> smartened by
>>>>> using PDF export instead. Only one thing is needed here: to export
>>>>> fonts as
>>>>> text and not as letter contours. Horizontal text would be excelent.
>>>>> In that
>>>>> way, the designers can throw away what they do not need and use
>>>>> Illustrators
>>>>> smart tools to make text follow lines and so on.
>>>>>
>>>>> Now, what I would like to know (my contact has some funds to spend on
>>>>> this
>>>>> topic):
>>>>>
>>>>> - Who can I address with my enhancement questions?
>>>>> - Who would be willing to spend about 40 hours on this and at what
>>>>> rate?
>>>>> - Would this fit the roadmap of qGIS development?
>>>>> - Would others like to join up and provide extra funding for this?
>>>>>
>>>>> I am curious to see what responses will be coming!
>>>>>
>>>>> Kind regards,
>>>>>
>>>>> Milo van der Linden
>>>>> +31616598808
>>>>>             
>>
>>
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