Debenu Quick PDF Library - PDF SDK Community Forum : Cropping pages with QuickPDF Library http://www.quickpdf.org/forum/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Sat, 04 Apr 2026 05:31:38 +0000 Sat, 07 Apr 2018 14:58:14 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 11.01 360 www.quickpdf.org/forum/RSS_post_feed.asp?TID=3445 <![CDATA[Debenu Quick PDF Library - PDF SDK Community Forum]]> http://www.quickpdf.org/forum/forum_images/QPDF_Forum_Title.png http://www.quickpdf.org/forum/ <![CDATA[Cropping pages with QuickPDF Library : I know this is a bit late, but...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post14166.html#14166 Author: HNRSoftware
Subject: 3445
Posted: 07 Apr 18 at 2:58PM

I know this is a bit late, but I needed to do some "cropping" work and based it on ukobsa's example.  I have discovered a few less-than-obvious things. 

First is that the example code only changes the first page.  It is necessary to use a page selection loop to change all of the pages -- that seems to work fine.

Second - this does not actually "crop" anything out of the file -- all of the existing data on each page is still there and the file remains about the same size.  I am guessing that the "SetCropBox" call just adds a small thing to each page telling it where the "useful" data is.

Adobe Acrobat does recognize the "CropBox" and does more or less what you would expect.  I'm not sure of exactly how it treats the cropbox on printing, but it is at least reasonable.

Thanks - Howard


Edited by HNRSoftware - 07 Apr 18 at 2:59PM]]> Sat, 07 Apr 2018 14:58:14 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post14166.html#14166 <![CDATA[Cropping pages with QuickPDF Library : I haven’t applied your advice...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13712.html#13712 Author: Richard Langin
Subject: 3445
Posted: 27 Mar 17 at 2:44PM

I haven’t applied your advice yet; in the meanwhile let me thank you all (Ukobsafirst) for your help. Gratefully.

]]> Mon, 27 Mar 2017 14:44:49 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13712.html#13712 <![CDATA[Cropping pages with QuickPDF Library : I should add that your code works...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13711.html#13711 Author: tfrost
Subject: 3445
Posted: 24 Mar 17 at 10:38AM

I should add that your code works for me.  I tried it on an A4 PDF and got a PDF 174.6mm by 261.8mm, with the edge strips of the original document missing.]]> Fri, 24 Mar 2017 10:38:24 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13711.html#13711 <![CDATA[Cropping pages with QuickPDF Library : If you see only the intersection,...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13710.html#13710 Author: tfrost
Subject: 3445
Posted: 24 Mar 17 at 10:23AM

If you see only the intersection, that is exactly what I would expect.  Is it not what you expect?  Here is an explanation from an Adobe manual I have (for PDF 1.7, dated 2008):

"The page object dictionary specifies these boundaries in the MediaBox, CropBox, BleedBox, TrimBox, and ArtBox entries, respectively (see Table 30). All of them are rectangles expressed in default user space units. The crop, bleed, trim, and art boxes shall not ordinarily extend beyond the boundaries of the media box. If they do, they are effectively reduced to their intersection with the media box. Figure 86 illustrates the relationships among these boundaries. (The crop box is not shown in the figure because it has no defined relationship with any of the other boundaries.)"
]]> Fri, 24 Mar 2017 10:23:58 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13710.html#13710 <![CDATA[Cropping pages with QuickPDF Library : Richard,here&#039;s a very simple...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13706.html#13706 Author: ukobsa
Subject: 3445
Posted: 23 Mar 17 at 4:11PM

Richard,

here's a very simple sample:


pdf := TDebenuPDFLibrary.Create;
  try
    pdf.LoadFromFile('d:\downloads\testseite.pdf', '');

    pdf.SetOrigin(0);
    dLeft := pdf.GetPageBox(2,0);
    dTop := pdf.GetPageBox(2, 1);
    dWidth := pdf.GetPageBox(2,2);
    dHeight:= pdf.GetPageBox(2,3);

    // CropBox :=  (dLeft, dTop, dLeft + dWidth, dTop - dHeight)
    
   // reduze size by 50 PDF units
    pdf.SetPageBox(2, dLeft + 50, dTop - 50, dWidth - 2 * 50, dHeight - 2 * 50);
    pdf.SaveToFile('d:\downloads\testseite_red.pdf')
  finally
    pdf.Free;
  end;


But please be aware that visually you will see only a change, when crop box is inside or equal media box (simplified said).
More general: what you see on screen is the intersection of Crop and Media box.

HTH,
Uli
]]> Thu, 23 Mar 2017 16:11:29 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13706.html#13706 <![CDATA[Cropping pages with QuickPDF Library : Sorry, though I have worked with...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13704.html#13704 Author: tfrost
Subject: 3445
Posted: 21 Mar 17 at 11:29PM

Sorry, though I have worked with crop boxes I do not have to hand an example which does just what you need, and at the moment do not have time to create one specially.  If you are able to post a very simple piece of your own code, to load, apply a crop, and save a file, then someone here may be able to spot what is causing it not to achieve the result you expect.]]> Tue, 21 Mar 2017 23:29:32 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13704.html#13704 <![CDATA[Cropping pages with QuickPDF Library : First, thank you for your reply.That’s...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13703.html#13703 Author: Richard Langin
Subject: 3445
Posted: 20 Mar 17 at 8:40PM

First, thank you for your reply.

That’s the problem: I do understand that the crop box is an “invisible” setting, yet I can’t put it to work effectively. I tried to set a crop box in a document, but after closing the application supposed to change this box, I opened the document back in Acrobat Reader and could see no change in the pages.

Getting straight to the point, may I ask you any example (or just a code snippet) which is supposed to actually crop the page, so that the document appears cropped next time I open it in a reader?

Thank you for your attention & support.
]]> Mon, 20 Mar 2017 20:40:16 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13703.html#13703 <![CDATA[Cropping pages with QuickPDF Library : Adding a crop box to a page does...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13701.html#13701 Author: tfrost
Subject: 3445
Posted: 20 Mar 17 at 6:33PM

Adding a crop box to a page does not change the underlying page, or delete any part of it from the file. As the documentation says, SetCropBox simply defines what part you want to be visible when you later display or print it.  So there is no visible evidence that a crop box exists until you actually render the page to screen or file, or print it.  That's how PDF cropping is done.  Does that explanation help?]]> Mon, 20 Mar 2017 18:33:41 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13701.html#13701 <![CDATA[Cropping pages with QuickPDF Library : I’m quite sure I’ve carefully...]]> http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13698.html#13698 Author: Richard Langin
Subject: 3445
Posted: 18 Mar 17 at 12:00PM

I’m quite sure I’ve carefully perused QuickPDF’s documentation, examples, references (both developer’s and functions’), yet I could find neither a simple explanation nor an example of a simple and straightforward operation: cropping pages. I’ve read the definition of methods like SetCropBox and SetRenderCropType, still I couldn’t understand how actually cropping is performed, where “actually cropping” trivially means, e.g. : “QuickPDF, take page three in the document loaded into the library and crop it with these top, left, height, width parameters I’m giving you”.

I assume this must be a very simple operation, hence I think / hope helping me will be easy and requiring a very short reply.

Thank you very much.


]]> Sat, 18 Mar 2017 12:00:02 +0000 http://www.quickpdf.org/forum/cropping-pages-with-quickpdf-library_topic3445_post13698.html#13698