Re: [OSM-talk] will walkingpapers printed on black and white work?
On Sat, Feb 27, 2010 at 11:11 AM, Tom Hughes t...@compton.nu wrote: On 27/02/10 05:21, Michal Migurski wrote: Interesting, I've been treating PDF uploads as errors, essentially. =) I wasn't aware of printers that spoke PDF instead of JPEG/TIFF. If this is a common problem I can look into ways of handling it. So far most of the image libraries I've been using don't really handle the complex postscript of PDF at all. The PDF that a scanner produces will normally just contain a big embedded bitmap image. No idea how easy that is to extract though. Tom I've used this to extract the jpgs that are inside pdfs: pdfimages -j foo.pdf bar Since pdf seems to be the encapsulating format of choice for fast auto loading scanners. -- /emj ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
On 27/02/10 05:21, Michal Migurski wrote: Interesting, I've been treating PDF uploads as errors, essentially. =) I wasn't aware of printers that spoke PDF instead of JPEG/TIFF. If this is a common problem I can look into ways of handling it. So far most of the image libraries I've been using don't really handle the complex postscript of PDF at all. The PDF that a scanner produces will normally just contain a big embedded bitmap image. No idea how easy that is to extract though. Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
Tom Hughes wrote: The PDF that a scanner produces will normally just contain a big embedded bitmap image. No idea how easy that is to extract though. Some scanner software produces a composite PDF with both vector content (OCRed text) and the bitmap image in front. The vector content is invisible - not sure whether this is done by layering, or some special PDF instruction, or whatever. Regardless, the effect is that the document looks as the original, but you can copy and paste the text. GhostScript will rasterise any PDF easily: gs -sDEVICE=jpeg -sOutputFile=output.jpg -dBATCH -dNOPAUSE -dSAFER input.pdf cheers Richard -- View this message in context: http://n2.nabble.com/will-walkingpapers-printed-on-black-and-white-work-tp4637798p462.html Sent from the General Discussion mailing list archive at Nabble.com. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [talk-ph] [OSM-talk] will walkingpapers printed on black and white work?
Thanks! On Fri, Feb 26, 2010 at 7:14 PM, Andy Robinson (blackadder-lists) ajrli...@googlemail.com wrote: Simon Hewison wrote: Sent: 26 February 2010 10:55 AM To: t...@openstreetmap.org Subject: Re: [OSM-talk] will walkingpapers printed on black and white work? On 26/02/2010 08:25, maning sambale wrote: Hi, I am using walking-papers printed on black white laser printing but I didn't tried uploading the scans (I don't have a scanner). I simply used the map as reference for my mapping. My questions is: If the map is printed on b/w will the rectification work when it's uploaded in walking-papers.org? Yes, colour is not used for the recification. Also, It doesn't warp the images - it shouldn't have to (unless your printer and scanner have serious problems), it just reads the 2D barcode and works out what part of the world it was, and arranges the scan as suitably scaled tiles. I've found that it doesn't work too well if the scan is a low resolution, and it can't cope with PDF scans. Sadly, this means that the nice HP 9000 multi-function printer at work doesn't really work for it, despite it being A3. But it's pretty easy to convert a PDF to a jpg, no? Cheers Andy ___ talk mailing list t...@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk -- cheers, maning -- Freedom is still the most radical idea of all -N.Branden wiki: http://esambale.wikispaces.com/ blog: http://epsg4253.wordpress.com/ -- ___ talk-ph mailing list talk-ph@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ph
[OSM-talk] will walkingpapers printed on black and white work?
Hi, I am using walking-papers printed on black white laser printing but I didn't tried uploading the scans (I don't have a scanner). I simply used the map as reference for my mapping. My questions is: If the map is printed on b/w will the rectification work when it's uploaded in walking-papers.org? -- cheers, maning -- Freedom is still the most radical idea of all -N.Branden wiki: http://esambale.wikispaces.com/ blog: http://epsg4253.wordpress.com/ -- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
Hi, My questions is: If the map is printed on b/w will the rectification work when it's uploaded in walking-papers.org? Yes. The rectification/orientation stuff is done on shape rather than colour. Ciarán ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
Simon Hewison wrote: Sent: 26 February 2010 10:55 AM To: talk@openstreetmap.org Subject: Re: [OSM-talk] will walkingpapers printed on black and white work? On 26/02/2010 08:25, maning sambale wrote: Hi, I am using walking-papers printed on black white laser printing but I didn't tried uploading the scans (I don't have a scanner). I simply used the map as reference for my mapping. My questions is: If the map is printed on b/w will the rectification work when it's uploaded in walking-papers.org? Yes, colour is not used for the recification. Also, It doesn't warp the images - it shouldn't have to (unless your printer and scanner have serious problems), it just reads the 2D barcode and works out what part of the world it was, and arranges the scan as suitably scaled tiles. I've found that it doesn't work too well if the scan is a low resolution, and it can't cope with PDF scans. Sadly, this means that the nice HP 9000 multi-function printer at work doesn't really work for it, despite it being A3. But it's pretty easy to convert a PDF to a jpg, no? Cheers Andy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
El 26/02/2010 12:14, Andy Robinson (blackadder-lists) escribió: Sadly, this means that the nice HP 9000 multi-function printer at work doesn't really work for it, despite it being A3. But it's pretty easy to convert a PDF to a jpg, no? It depends. There are unix utilities to extract images from PDF files, but that may mess with some scanner's automagic built-in OCR stuff (i.e. the scanner will interpret parts of the image as text, and you won't be able to extract it properly, and it will mess the upload, and the FSM will kill a kitten). You could also use pdftoppm to rasterize the PDF, but that will incur in a quality loss. And we the geotards are pretty picky about raster quality loss :-) Cheers, -- Iván Sánchez Ortega i...@sanchezortega.es ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
On Fri, Feb 26, 2010 at 10:55 AM, Simon Hewison si...@zymurgy.org wrote: Also, It doesn't warp the images - it shouldn't have to (unless your printer and scanner have serious problems) That might be a useful feature, since it lets you take photos of the paper instead of having to get a 'real' scanner ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
On Feb 26, 2010, at 2:55 AM, Simon Hewison wrote: I've found that it doesn't work too well if the scan is a low resolution, and it can't cope with PDF scans. Sadly, this means that the nice HP 9000 multi-function printer at work doesn't really work for it, despite it being A3. Interesting, I've been treating PDF uploads as errors, essentially. =) I wasn't aware of printers that spoke PDF instead of JPEG/TIFF. If this is a common problem I can look into ways of handling it. So far most of the image libraries I've been using don't really handle the complex postscript of PDF at all. -mike. michal migurski- m...@stamen.com 415.558.1610 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] will walkingpapers printed on black and white work?
On Feb 26, 2010, at 12:38 PM, OJ W wrote: On Fri, Feb 26, 2010 at 10:55 AM, Simon Hewison si...@zymurgy.org wrote: Also, It doesn't warp the images - it shouldn't have to (unless your printer and scanner have serious problems) That might be a useful feature, since it lets you take photos of the paper instead of having to get a 'real' scanner It does warp the images *a little*, in the sense that if you rotate your scan Walking Papers will be able to compensate. If you can take a nice, flat photo of a print from the application, there should be no problems finding the code and using the image. The problem is that not a lot of photos are nice and flat, and I wasn't able to figure out how to deal with all the potential variables: lenses, viewing angles, curled paper, variable lighting, etc. I'm thrilled to death that people are using it though! -mike. michal migurski- m...@stamen.com 415.558.1610 ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
