image in Flatedecode stream without metadata in dictionary
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I'm providing an example of a pdf file where I see 4 "conceptual images", in the psychological visual sense (I understood that they are not images from the pdf point of view). My aim is to edit the pdf file adding a (rectangular) border to such "conceptual images". Is there an easy way to do it with iText, or should I handcraft some sort of low level parsing myself? Thanks -----Messaggio originale----- Da: Leonard Rosenthol [mailto:[hidden email]] Inviato: martedì 1 novembre 2011 15:22 A: Post here Oggetto: Re: [iText-questions] R: R: R: image in Flatedecode stream without metadata in dictionary One key question - and this applies EQUALLY to both Image as well as Form Xobjects. Do you want the physical size (what the box would be if rendered w/o any context) _OR_ the effective size (taking the current transformation matrix into account)? If effective, then you need to consider that an Xobject can be called from multiple places in the same document with different CTMs. What do you want to do in that case? And this especially applies to the POSITION item you listed below. Position is determined by the CALLING CONTEXT (aka the content stream that invoked (via the Do operator) the Xobject). So that would imply you want effective size, in which case, you need to step back and look at using the page content parser feature of iText. Leonard On 11/1/11 10:00 AM, "Giampaolo Capelli" <[hidden email]> wrote: >I don't have problems with th concept of image, I perfectly knows the >difference between raster and and vector, rather it seems you didn't >get what I need, unlike other partipants to this thread. I need a way >to render the object expressed by the pdf syntax in a way that it >would be possible to get its width and height and position, or I need >to get this information from the pdf data, if possible > >2011/11/1, Leonard Rosenthol <[hidden email]>: >> You seem to have a problem with the concept of "images". There are two >> types: >> - Raster (<http://en.wikipedia.org/wiki/Raster_graphics>) >> - Vector (<http://en.wikipedia.org/wiki/Vector_graphics>) >> >> An Image XObject is a Raster image, while a Form XObject is a vector >> image. >> >> So you need to determine how you wish to deal with the differences in >>your >> product. >> >> Leonard >> >> >> On 11/1/11 7:40 AM, "Giampaolo Capelli" <[hidden email]> wrote: >> >>>But since Acrobat Reader is able to properly render my pdf file, >>>I guess there should be some way to get the data I need. >>> >>>Do I need to use a third party library to parse that pdf syntax, >>>or to render the images and calculate myself their attributes? >>> >>> >>>-----Messaggio originale----- >>>Da: 1T3XT BVBA [mailto:[hidden email]] >>>Inviato: martedì 1 novembre 2011 12:25 >>>A: Post all your questions about iText here >>>Oggetto: Re: [iText-questions] R: R: image in Flatedecode stream without >>>metadata in dictionary >>> >>>On 1/11/2011 11:39, Giampaolo Capelli wrote: >>>> That ISO reports the dictionary's BBox entry, that is required. >>>> >>>> I've decoded one of my Flatedecode streams, it looks like this >>>> Does it look like a form XObject? >>> >>>Yes, that's PDF syntax. This means you don't have an image, but a Form >>>XObject. >>>If you want to have the Form XObject to have a BBox, please ask the >>>people at GhostScript to add one. >>>If they don't provide the required BBox value, ask them how you're >>>supposed to get the width and the height. >>> >>>------------------------------------------------------------------------ >>>-- >>>-- >>>-- >>>RSA® Conference 2012 >>>Save $700 by Nov 18 >>>Register now >>>http://p.sf.net/sfu/rsa-sfdev2dev1 >>>_______________________________________________ >>>iText-questions mailing list >>>[hidden email] >>>https://lists.sourceforge.net/lists/listinfo/itext-questions >>> >>>iText(R) is a registered trademark of 1T3XT BVBA. >>>Many questions posted to this list can (and will) be answered with a >>>reference to the iText book: http://www.itextpdf.com/book/ >>>Please check the keywords list before you ask for examples: >>>http://itextpdf.com/themes/keywords.php >>>----- >>>Nessun virus nel messaggio. >>>Controllato da AVG - www.avg.com >>>Versione: 10.0.1411 / Database dei virus: 2092/3988 - Data di rilascio: >>>31/10/2011 >>> >>> >>>------------------------------------------------------------------------ >>>-- >>>---- >>>RSA® Conference 2012 >>>Save $700 by Nov 18 >>>Register now >>>http://p.sf.net/sfu/rsa-sfdev2dev1 >>>_______________________________________________ >>>iText-questions mailing list >>>[hidden email] >>>https://lists.sourceforge.net/lists/listinfo/itext-questions >>> >>>iText(R) is a registered trademark of 1T3XT BVBA. >>>Many questions posted to this list can (and will) be answered with a >>>reference to the iText book: http://www.itextpdf.com/book/ >>>Please check the keywords list before you ask for examples: >>>http://itextpdf.com/themes/keywords.php >> >> >> >>------------------------------------------------------------------------- >>----- >> RSA® Conference 2012 >> Save $700 by Nov 18 >> Register now >> http://p.sf.net/sfu/rsa-sfdev2dev1 >> _______________________________________________ >> iText-questions mailing list >> [hidden email] >> https://lists.sourceforge.net/lists/listinfo/itext-questions >> >> iText(R) is a registered trademark of 1T3XT BVBA. >> Many questions posted to this list can (and will) be answered with a >> reference to the iText book: http://www.itextpdf.com/book/ >> Please check the keywords list before you ask for examples: >> http://itextpdf.com/themes/keywords.php >> > > >-- >Giampaolo Capelli >[hidden email] >[hidden email] >(+39) 338 7139111 >--------------------------- >skype: giampow >icq: 96521070 >msn: [hidden email] >gtalk: [hidden email] > >-------------------------------------------------------------------------- >---- >RSA® Conference 2012 >Save $700 by Nov 18 >Register now >http://p.sf.net/sfu/rsa-sfdev2dev1 >_______________________________________________ >iText-questions mailing list >[hidden email] >https://lists.sourceforge.net/lists/listinfo/itext-questions > >iText(R) is a registered trademark of 1T3XT BVBA. >Many questions posted to this list can (and will) be answered with a >reference to the iText book: http://www.itextpdf.com/book/ >Please check the keywords list before you ask for examples: >http://itextpdf.com/themes/keywords.php ---------------------------------------------------------------------------- -- RSA® Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ iText-questions mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/itext-questions iText(R) is a registered trademark of 1T3XT BVBA. Many questions posted to this list can (and will) be answered with a reference to the iText book: http://www.itextpdf.com/book/ Please check the keywords list before you ask for examples: http://itextpdf.com/themes/keywords.php ----- Nessun virus nel messaggio. Controllato da AVG - www.avg.com Versione: 10.0.1411 / Database dei virus: 2092/3988 - Data di rilascio: 31/10/2011 ------------------------------------------------------------------------------ RSA® Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ iText-questions mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/itext-questions iText(R) is a registered trademark of 1T3XT BVBA. Many questions posted to this list can (and will) be answered with a reference to the iText book: http://www.itextpdf.com/book/ Please check the keywords list before you ask for examples: http://itextpdf.com/themes/keywords.php |
test.pdf (48K) |
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On 1/11/2011 17:09, Giampaolo Capelli wrote:
> In the attachment > > I'm providing an example of a pdf file where I see 4 "conceptual images", in > the psychological visual sense > (I understood that they are not images from the pdf point of view). > > My aim is to edit the pdf file adding a (rectangular) border to such > "conceptual images". > > Is there an easy way to do it with iText, > or should I handcraft some sort of low level parsing myself? "internal view" of your PDF. Look at the /Resources Dictionary. It doesn't contain an /XObjects entry. This means that there are NO Image XObjects (this you already knew), but NO Form XObjects either (we assumed there were Form XObjects, but that must have been a misunderstanding)! Where are the four images? Well... as far as the PDF is concerned, there are no FOUR images. As you rightly point out, they are only there in the psychological, visual sense (you've phrased that very well). As far as the PDF is concerned, there's only ONE sequence of PDF syntax: the page content stream (object 5 in the PDF), which is the /Contents entry of the page dictionary (object 4). All the paths and shapes on that page are constructed using operators such as moveTo (m), lineTo (l) and curveTo (c). I don't know any software (not iText, not any other software) that is intelligent enough to find out which paths and shapes belong to which "conceptual" of "visual" image. I don't know any way to automate the detection of these images. ------------------------------------------------------------------------------ RSA® Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ iText-questions mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/itext-questions iText(R) is a registered trademark of 1T3XT BVBA. Many questions posted to this list can (and will) be answered with a reference to the iText book: http://www.itextpdf.com/book/ Please check the keywords list before you ask for examples: http://itextpdf.com/themes/keywords.php |
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