How to determine if page is blank?

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   Hi!

I need to check if a page of an existing pdf file is completely blank. Well, of cource I can check the page text. But how about images? The function ImageCount is not applicable.

Any ideas? I already thought about using the GetPageContent function. But my knowledge about the structure is very limited.

Any help is greatly appreciated.

Regards
Jan

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JanN Members Profile Find Members Posts Senior Member Joined: 29 Oct 05 Location: Germany Status: Offline Points: 116	Post Options Post Reply Quote JanN Report Post Thanks(0) Quote Reply Topic: How to determine if page is blank? Posted: 23 Nov 07 at 10:44AM
	Hi! I need to check if a page of an existing pdf file is completely blank. Well, of cource I can check the page text. But how about images? The function ImageCount is not applicable. Any ideas? I already thought about using the GetPageContent function. But my knowledge about the structure is very limited. Any help is greatly appreciated. Regards Jan

Ingo Members Profile Find Members Posts Moderator Group Joined: 29 Oct 05 Status: Offline Points: 3524	Post Options Post Reply Quote Ingo Report Post Thanks(0) Quote Reply Posted: 23 Nov 07 at 5:10PM
	Hi Jan! I do it this way ... With this code i read the pdf-content into a string: textkomplett := ''; fs := TFileStream.Create(Edit1.Text,fmOpenRead+fmShareDenyWrite); try SetLength(textkomplett,fs.Size); fs.Read(PChar(textkomplett)^,fs.Size); finally fs.Free; end; If i'm searching for images inside the content must be the tag "/Image": If Pos('/Image', textkomplett) > 0 Then mibi.Text := 'Yes' Else mibi.Text := 'No'; Best regards, Ingo

JanN Members Profile Find Members Posts Senior Member Joined: 29 Oct 05 Location: Germany Status: Offline Points: 116	Post Options Post Reply Quote JanN Report Post Thanks(0) Quote Reply Posted: 24 Nov 07 at 9:52AM
	Hi Ingo! Thanks for your reply. But the way you do it only tells me if there are any images in the pdf file. So far so well. But I need to know if one of the images is used for one specific page. Perhaps this is possible by getting the object numbers of the images and check if they are referenced to in the page. Edited by JanN - 24 Nov 07 at 9:54AM

JanN Members Profile Find Members Posts Senior Member Joined: 29 Oct 05 Location: Germany Status: Offline Points: 116	Post Options Post Reply Quote JanN Report Post Thanks(0) Quote Reply Posted: 05 Dec 07 at 8:03AM
	One last try. I haven't been successful, yet. My knowledge of the pdf structure is not sufficient for solving this problem. Does anyone have another idea or perhaps a piece of code ? Best regards, Jan

krom Members Profile Find Members Posts Beginner Joined: 20 Sep 07 Status: Offline Points: 5	Post Options Post Reply Quote krom Report Post Thanks(0) Quote Reply Posted: 06 Dec 07 at 9:27AM
	h:=QP.DAOpenFile(filename); p:=QP.DAFindPage(h,pagenum); imlist:=QP.DAGetPageImageList(h,p); imcnt:=QP.DAGetImageListCount(h,imlist); if imcnt=0 then 'No images'

JanN Members Profile Find Members Posts Senior Member Joined: 29 Oct 05 Location: Germany Status: Offline Points: 116	Post Options Post Reply Quote JanN Report Post Thanks(0) Quote Reply Posted: 06 Dec 07 at 10:06AM
	Thanks for that reply. Once again a surprise what the DA-functions are able to do. Best regards, Jan