DPI : how it works ?

Discussions on GFL SDK, the graphic library for reading and writing graphic files

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rumicosly91
Posts: 1
Joined: Mon Jul 16, 2007 6:46 am

DPI : how it works ?

Post by rumicosly91 »

hi,

i read severals post about the DPI in this forum. I have few questions about it :
- what do exactly the api when i change the xpdi / ydpi value ? some post said it only change the metadata value some others said it change too the size of the picture... In my tests, only the value of the metadata is changed...
- So how to change the size of the picture when changing the dpi value ? like in photosop for instance...

i'm a bit lost...

sylvain
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xnview
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Joined: Mon Oct 13, 2003 7:31 am
Location: France

Re: DPI : how it works ?

Post by xnview »

rumicosly91 wrote:- what do exactly the api when i change the xpdi / ydpi value ? some post said it only change the metadata value some others said it change too the size of the picture... In my tests, only the value of the metadata is changed...
Change only the DPI values stored in the file (if you save it)
- So how to change the size of the picture when changing the dpi value ? like in photosop for instance...
Currently there is no way, you must compute the new width/height in pixels
Pierre.