How to get "Bounding box" (inked area)

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   Welcome,

I'm testing library v.8.13, Delphi, DCU.

QP can get MediaBox,CropBox,BleedBox,TrimBox,ArtBox from PDF page.

Any idea, how to get "Bounding box" (inked area) of PDF page without rasterizing?

For example GhostScript can get this by:

 gs -dNOPAUSE -dBATCH -sDEVICE=bbox 

  Result like this:

   %%BoundingBox: 14 37 570 719

   %%HiResBoundingBox: 14.308066 37.547999 569.495061 718.319158

I'm try:

1. Detect Bounding box (?)

2. Crop page to Bounding box (crop to inked area, removing white margins) - by CapturePage,DrawCapturePage.

How to detect Bounding box? 

Regards,

Adam

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
ADev Members Profile Find Members Posts Beginner Joined: 10 Feb 12 Status: Offline Points: 8	Post Options Post Reply Quote ADev Report Post Thanks(0) Quote Reply Topic: How to get "Bounding box" (inked area) Posted: 10 Feb 12 at 10:58AM
	Welcome, I'm testing library v.8.13, Delphi, DCU. QP can get MediaBox,CropBox,BleedBox,TrimBox,ArtBox from PDF page. Any idea, how to get "Bounding box" (inked area) of PDF page without rasterizing? For example GhostScript can get this by: gs -dNOPAUSE -dBATCH -sDEVICE=bbox Result like this: %%BoundingBox: 14 37 570 719 %%HiResBoundingBox: 14.308066 37.547999 569.495061 718.319158 I'm try: 1. Detect Bounding box (?) 2. Crop page to Bounding box (crop to inked area, removing white margins) - by CapturePage,DrawCapturePage. How to detect Bounding box? Regards, Adam

AndrewC Members Profile Find Members Posts Moderator Group Joined: 08 Dec 10 Location: Geelong, Aust Status: Offline Points: 841	Post Options Post Reply Quote AndrewC Report Post Thanks(0) Quote Reply Posted: 10 Feb 12 at 12:01PM
	QP.GetPageBox will allow you to get all the box values you need. http://www.quickpdflibrary.com/help/quickpdf/GetPageBox.php SetRenderCropType will tell which box to crop when rendering. http://www.quickpdflibrary.com/help/quickpdf/SetRenderCropType.php CapturePage will capture the entire PDF contents and it doesn't know how to crop white margins. You may have to reset the pages boxes manually to get the margin you need using QP.SetPageBox. Andrew. Andrew

ADev Members Profile Find Members Posts Beginner Joined: 10 Feb 12 Status: Offline Points: 8	Post Options Post Reply Quote ADev Report Post Thanks(0) Quote Reply Posted: 10 Feb 12 at 1:28PM
	Andrew, thank you for your answer. In my pdf file (A3 page), GhostScript return: %%BoundingBox: 56 78 1119 772 %%HiResBoundingBox: 56.599100 78.070990 1118.497817 771.208992 QP results: page has only 1 box (QP.HasPageBox): MediaBox: 0,1191,842,1191,842,0 Pdf created by PdfCreator v. 1.2.3 (PdfCreator use GhostScript 9.04) BoundingBox from GhostScript has a good result. Any other ideas? Regards, Adam

AndrewC Members Profile Find Members Posts Moderator Group Joined: 08 Dec 10 Location: Geelong, Aust Status: Offline Points: 841	Post Options Post Reply Quote AndrewC Report Post Thanks(0) Quote Reply Posted: 10 Feb 12 at 1:45PM
	I would need to see the PDF to make reasonable comment. It is a bit hard trying to guess without seeing the PDF file.

ADev Members Profile Find Members Posts Beginner Joined: 10 Feb 12 Status: Offline Points: 8	Post Options Post Reply Quote ADev Report Post Thanks(0) Quote Reply Posted: 10 Feb 12 at 2:27PM
	Thanks, sample file (zip packed) is in: Test pdf file

AndrewC Members Profile Find Members Posts Moderator Group Joined: 08 Dec 10 Location: Geelong, Aust Status: Offline Points: 841	Post Options Post Reply Quote AndrewC Report Post Thanks(0) Quote Reply Posted: 11 Feb 12 at 2:22AM
	If you open the PDF file in a text editor you will see that the only page box defined is the MediaBox. 4 0 obj <</Type/Page/MediaBox [0 0 842 1191] /Rotate 90/Parent 3 0 R /Resources<</ProcSet[/PDF /Text] /Font 8 0 R >> It is most likely that GhostScript is keeping track of the rendering process and is updating the bounding box as renders. Quick PDF Library doens't have this capability. It is impossible to calculate this value without parsing the full content stream which happens when you render the full file. You could get a very close approximation by rendering the PDF page to a Bitmap and then checking for pixels in all four directions until a non white pixel is found. Andrew.

ADev Members Profile Find Members Posts Beginner Joined: 10 Feb 12 Status: Offline Points: 8	Post Options Post Reply Quote ADev Report Post Thanks(0) Quote Reply Posted: 11 Feb 12 at 5:06PM
	Ok Andrew, thank you for your interest, I think, GS detect this bounduary by detect all bounduary objects (its faster an rasterizing complete objects), also with rasterizing fonts.. I can't use GS, the commercial problem exists for me. You are right, inked area is available after rasterizing all of page content. Im know about this topic But .. look in my first post : "Any idea, how to get "Bounding box" (inked area) of PDF page without rasterizing? " This is one of the key to my program. I can analyze bitmaps, but first I need to have the bitmap. Fast have .. My example file is small, but in reality I use large files (e.g. 900x2000 mm files, with raster and vector contents). Thank you for good intentions, I will seek further .. Edited by ADev - 12 Feb 12 at 10:48AM