Hi Tilman, I tried your idea but am having trouble getting the result I wanted. My hope was to use a stock standard pdf rendering library (mupdf or android.graphics.pdf.PdfRenderer ) to render to a bitmap and then use opengl to do the blend. However mupdf renders a white background BEFORE rendering the pdf commands. So I will try to modify mupdf.
Thanks for your help, Robert. On 22 Jun 2016 4:25 pm, "Tilman Hausherr" <[email protected]> wrote: > Am 22.06.2016 um 00:05 schrieb Robert Van Gemert: > >> Files exported from android google slides would work for me. >> >> https://www.dropbox.com/s/ncnjt8tlgzasb6f/slide_test.pdf?dl=0 >> > > Strategy 1: > use the command line utilities, run WriteDecodedDoc, then use an editor > and overwrite this part with blanks: > > /Image3 > Do > > > The file is huge now, sadly. > > Strategy 2: > > In the source code download, in the examples, there's a program > RemoveAllText.java. That one shows how to work with the content stream: > > for (Object token : tokens) > { > if( token instanceof Operator) > { > Operator op = (Operator)token; > if( op.getName().equals( "TJ") || > op.getName().equals( "Tj" )) > { > //remove the one argument to this operator > newTokens.remove( newTokens.size() -1 ); > continue; > } > } > newTokens.add( token ); > } > > Now you don't want to remove "TJ", you want to remove "Do". I just tested > this, it works for your file. (But it might now work with files that have a > different structure). > > Tilman > > > > >> Thanks for your help. >> >> Robert >> On 22 Jun 2016 2:32 am, "Tilman Hausherr" <[email protected]> wrote: >> >> Am 21.06.2016 um 13:12 schrieb Robert Van Gemert: >>> >>> Hi, >>>> >>>> I wish to use pdf as a graphics overlay over video so I need to make the >>>> page background transparent or remove it. Can I use pdfbox to >>>> preprocess a >>>> pdf file? >>>> My OS is Android. Initial tests show I cannot use pdfbox for rendering >>>> but >>>> preprocessing may work. >>>> >>>> Thanks, >>>> >>>> Robert >>>> >>>> >>>> This is difficult to answer as there may be many methods to put a >>> "background". There is no <BACKGROUND="image.jpg"/> command in PDF. Does >>> your question apply to one specific PDF or to all possible PDFs in the >>> world? If only one, please upload it somewhere. >>> >>> Tilman >>> >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: [email protected] >>> For additional commands, e-mail: [email protected] >>> >>> >>> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
