It sounds like a new read through the PDF standard or a book such as mine or Bruno’s would be helpful for you.
Clipping paths are used to CHANGE what the user sees by “clipping” visible objects to a specific area, so that anything outside the clip will be hidden. So if you are concerned about hidden objects, you would need to evaluate the clipping regions (vs. throwing them away) and apply them against impacted content. Z-ordering is defined in PDF by the order of the operators in the stream. First in, First Drawn - so that the first graphic object in the stream has the lowest (bottom) z-index and then each after increases that z-index (ie. Goes on top). Leonard On 10/21/14, 11:25 AM, "FDnC Red" <fdnc...@yahoo.com> wrote: >Leonard, Michael, >Thanks for your response. Here's a followup. > >Leonard - You mention clipping paths. I'm already filtering on operator >W and W* to find clipping paths and excluding those paths. Are you >saying there's an another way to determine clipping paths that I may not >be filtering out? If so please advise. > >Michael, Leonard - I understand your rendering comments. What I don't >understand is how I could ever tell what's on top of what. Ideally there >would be a Z-order to the paths but I see no such thing. Without such a >mechanism I'm not sure how I would tell what is on top and what is not. >Did I miss the z-order operator or some such thing? > >Thanks, >Darren > > > >On Monday, October 20, 2014 10:35 AM, mkl <m...@wir-sind-cool.org> wrote: >Darren, > >Leonard Rosenthol wrote > > > >> The only way to do that is to basically render the page and then analyze >> each path. The most common reason (beyond what you¹ve already >>mentioned) >> is that they are clipped out - meaning that there is a clipping path in >> place and these are outside of it. > >Another very common cause is that the line is drawn... and then covered by >something else. > >The one page in your PDF has an extremely large content stream, more than >5MB uncompressed, so it is very likely that some things drawn in it are >covered by others. > >To check for this, you'll have to parse it, remember all the objects you >are >interested in, and check whether any newly drawn object covers any of >them, >partially or completely. I.e. you'll basically have to render the page, >just >like Leonard said. ;) > >Regards, Michael > > > >-- >View this message in context: >http://itext-general.2136553.n4.nabble.com/How-to-determine-what-is-visibl >e-tp4660471p4660473.html >Sent from the iText - General mailing list archive at Nabble.com. > >-------------------------------------------------------------------------- >---- >Comprehensive Server Monitoring with Site24x7. >Monitor 10 servers for $9/Month. >Get alerted through email, SMS, voice calls or mobile push notifications. >Take corrective actions from your mobile device. >http://p.sf.net/sfu/Zoho >_______________________________________________ >iText-questions mailing list >iText-questions@lists.sourceforge.net >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 > >-------------------------------------------------------------------------- >---- >Comprehensive Server Monitoring with Site24x7. >Monitor 10 servers for $9/Month. >Get alerted through email, SMS, voice calls or mobile push notifications. >Take corrective actions from your mobile device. >http://p.sf.net/sfu/Zoho >_______________________________________________ >iText-questions mailing list >iText-questions@lists.sourceforge.net >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 ------------------------------------------------------------------------------ Comprehensive Server Monitoring with Site24x7. Monitor 10 servers for $9/Month. Get alerted through email, SMS, voice calls or mobile push notifications. Take corrective actions from your mobile device. http://p.sf.net/sfu/Zoho _______________________________________________ iText-questions mailing list iText-questions@lists.sourceforge.net 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
