Extract image

An Example to extract images can be found here:

http://www.quickpdf.org/forum/forum_posts.asp?TID=376&KW=swb1

Hi Quicker!

Steves' example is what you need. You only have to lay a loop "page by page" around it. You can separate each page and then analyze each page with Steves' code.

Best regards,
Ingo

Quicker,

 

The problem is that an image is not necessarily “on” a given page. Images are part of the document and typically only a reference to an image is on a given page. This allows the PDF to be more efficient in the storage and display of images, particularly when they are redundant, for example: a company logo on a multiple page invoice.

 

The direct solution to this may be somewhat complicated. You would need to get a list of images and their references and then using GetPageContent you would cross reference the list of image references on the page. This is definitely advance topic and would require pretty good understanding of the PDF specification. I think a function of this sort would make a nice addition to the library but I don’t think that a simple way of doing this exists in the library today.

 

The indirect solution is to separate each page from the document, using ExtractPages, and then, as separate documents, use the code that I supplied. This is not very efficient and will require time and I/O however it should work.

 

An example to extract pages goes something like this:

 

procedure TForm1.btnExtractPagesClick(Sender: TObject);

var PageIndex : integer;

      FirstName : string;

      NewDocID : integer;

begin

      qPDF := TiSEDQuickPDF.Create;

      qPDF.UnlockKey(MY_QDPF_KEY);

      if OpenDialog1.Execute then

            begin

            qPDF.LoadFromFile( OpenDialog1.FileName );

            FirstName := copy(OpenDialog1.FileName,1,pos('.pdf',lowercase(OpenDialog1.FileName)));

            for PageIndex := 1 to qPDF.PageCount do

                  begin

                  qPDF.ExtractPages(PageIndex,1);

                  NewDocID := qPDF.SelectedDocument;

                  qPDF.SaveToFile(FirstName + IntToStr(PageIndex) + '.pdf' );

                  qPDF.RemoveDocument(NewDocID);

                  end

            end;

      qPdf.Free;

end;

 

 

sb

 

 

 

Quicker,

  

I suspect that for practical purposes the document capacity of a TiSEDQuickPDF object is unlimited. Memory and processing time are probably the only factors you will need to be concerned with.

 

As far as your code is concerned; my understanding of how QuickPDF works is largely due to trial and error. Your code looks like it ought to work. Try it. If it works - how wrong can it be? If it does not work you may want to try separating the split page and extract images functions into different operations.

 

sb

 

Yes. That I think that is a safe assumption. I have not inspected this code carefully however it appears to be doing the right thing as far cleaning up after itself.

 

sb