File blows up after simple change

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enaef
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Joined: Sat Apr 02, 2011 1:53 pm

File blows up after simple change

Post by enaef »

Hi

The attached file is 2.92 MB in its native form. After a simple change (like highlighting of one word) and saving the file, it blows up to 10 MB.

How this?

Thanks, Ernst
Attachments
CHOP-2012.pdf
CHOP-2012.pdf
(2.93 MiB) Downloaded 895 times
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Tracker Supp-Stefan
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Re: File blows up after simple change

Post by Tracker Supp-Stefan »

Hello Ernst,

I have asked our devs to check why this is happening as I did manage to reproduce it at my end.
We will post again in this topic later when we have a bit more news.

Best,
Stefan
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Lzcat - Tracker Supp
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Re: File blows up after simple change

Post by Lzcat - Tracker Supp »

This is hybrid document - document produced using a recent update to the PDF specification (e.g. features like compressed objects and xref streams, added in spec. version 1.5), but with PARTIAL compatibility with older readers which do not understand these new features.

Therefore this file reports that that it has PDF spec version 1.3 (but in fact it is 1.5 or higher). Normally hybrid files should contain another record with the real PDF spec. version (older readers ignore it), but this file does not contain this and thus has been incorrectly formatted.

So when our Viewer saves this file it assume that it is has PDF spec. version 1.3 and tries to save it with the minimum supported PDF spec. we support - V1.4 (it is supported in most older readers). But 1.4 spec. version does not allow compress objects or use object streams, so file became much larger.
In the attached file I have changed only one byte to "upgrade" it to version 1.5, now it saves almost as the same size.
Attachments
CHOP-2012 - Copy.pdf
(2.93 MiB) Downloaded 242 times
Victor
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Please archive any files posted to a ZIP, 7z or RAR file or they will be removed and not posted.
enaef
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Posts: 46
Joined: Sat Apr 02, 2011 1:53 pm

Re: File blows up after simple change

Post by enaef »

Marvellous :!:

You guys are extremly quick an helpful - as always

Ernst

I guess I couldn't have done this change to 1.5 by myself?
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John - Tracker Supp
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Re: File blows up after simple change

Post by John - Tracker Supp »

Hi Ernst - u could but it would not be reccomended as you may inadvertenty cause other issues.

If you do try - always work on a copy and not the original...
If posting files to this forum - you must archive the files to a ZIP, RAR or 7z file or they will not be uploaded - thank you.

Best regards
Tracker Support
http://www.tracker-software.com
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