java - how to extract PDF watermark content using iText apis -

-

i going through itext api docs & able create pdf watermark image or text did not find method get/extract watermark content pdf.

so have pdf document containing watermarked text/image & want extract text or img , validate not able do.

how extract watermark content using itext apis? or there other way validate watermark content?

by validate mean if have existing pdf/image watermarked text [as done in 2nd link in above ref], want check whether has expected text/image.

references:

how extract watermark content using itext apis? or there other way validate watermark content?

extracting watermark content?

there nothing special watermarks in pdfs in contrast regular page content. merely

  • appear pretty in content stream , other content later in stream, therefore, drawn above it; or they

  • appear pretty late in content stream have kind of transparency applied.

actually there type of watermarks is special, so-called watermark annotations. as these annotation can lost when documents merged or otherwise manipulated, though, hardly ever used.

furthermore different pdf generating software suites offering way add watermarks in respective individual way. thus, cannot recognize watermarks special operations done in specific unique pattern.

already itext examples referred apply different kinds of watermarks

  • moviecountries2 draws gray large text using angled base line.
  • stampstationery copies complete page pdf (which may visually have foreground , background material) separate object inside target pdf , adds reference object @ beginning of every page of target.
  • insertpages references page pdf on every newly generated target document page.

thus, blind watermark extraction virtually impossible.

validating watermark content!

you might try validation, though, if know searching for. not merely search (in pdf not existing) fixed watermark stream instead whole page content.

itext offers classes of parser package allow extraction of text and/or bitmap images content streams. @ samples referenced keywords parsing pdf > extracting images , parsing pdf > extracting text.

you merely have check whether image or text expect can found these classes positioned , styled expect.


Comments

Post a Comment

Popular posts from this blog

windows - Single EXE to Install Python Standalone Executable for Easy Distribution -

-
i used pyinstaller create standalone exe file pyqt project. did not use single file option because exe created single file option takes long open. therefore, pyinstaller created dist folder contains bunch of files including program.exe file. create setup.exe file place contents of dist folder in program directory , create shortcut in start menu , on desktop. want super simple user. maybe setup.exe files when download program cnet. found inno-setup, looks promising. however, not know if there special considerations because program standalone program create python/pyqt program. thanks! have experience task? there program using task not know about? inno-setup or nsis easiest use. tell them files include , put them , create nice installer you. wrote short tutorial on experiences using innosetup might find helpful: http://www.blog.pythonlibrary.org/2008/08/27/packaging-wxpymail-for-distribution/ note tutorial based around wxpython app wrote, concepts same.
Read more

c# - Access objects in UserControl from MainWindow in WPF -

-
i have simple xaml, how can change text property of textblock in usercontrol1 mainwindow ? <window x:class="refactorxaml.mainwindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:refactorxaml="clr-namespace:refactorxaml" title="mainwindow" height="350" width="525"> <grid> <grid.rowdefinitions> <rowdefinition height="100"></rowdefinition> <rowdefinition height="100"></rowdefinition> </grid.rowdefinitions> <grid> <refactorxaml:usercontrol1></refactorxaml:usercontrol1> </grid> <grid grid.row="1"> <button>change text</button> </grid> </grid> </window> <usercon...
Read more

javascript - How to name a jQuery function to make a browser's back button work? -

-
i'm trying write function ajaxyfy web site, works perfect, except function button. that's have now: function loading() { if (typeof history.pushstate !== "undefined") { var historycount = 0; $('.menu-item, .logo').on('click','a',function(e){ e.preventdefault(); $(this).data('clicked', true); if ($(this).is('.logo a')) { var homepage = $(this).attr('href'); function1(homepage); history.pushstate(null, null, homepage); } else if ($(this).is('.projects a')) { var projects = $(this).attr('href'); function2(projects); history.pushstate(null, null, projects); } else { var pages = $(this).attr('href'); function3(pages); history.pushstate(null, null, pages); ...
Read more