Dpi for PDF not correct

Ideas for improvements and requests for new features in XnView Classic

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Troken
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Location: Sweden

Dpi for PDF not correct

Post by Troken »

Hi everybody,

the preview-info is great, for instance showing DPI. But for vectorgraphics (AI, most PDFs and some EPSs) its always showing 72 DPI, which isn't correct. My guess is that it is the DPI for the preview in XnView, not the actual image. It's confusing, wouldn't it be better to write something else? Or not at all?

Any opinions on this?
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xnview
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Re: Dpi for PDF not correct

Post by xnview »

Troken wrote:Hi everybody,

the preview-info is great, for instance showing DPI. But for vectorgraphics (AI, most PDFs and some EPSs) its always showing 72 DPI, which isn't correct. My guess is that it is the DPI for the preview in XnView, not the actual image. It's confusing, wouldn't it be better to write something else? Or not at all?

Any opinions on this?
Yes, it's the dpi used to import the vector file... Ok i'll try to show original dpi
Pierre.
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Troken
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Location: Sweden

Post by Troken »

A PDF can contain images with different DPI, I wonder if it is possible to solve it easily.
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helmut
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Post by helmut »

Vector graphics like PDF or AI consist of vectors, not pixels, so there is no such thing as DPI. PDF may contain an bitmap image, but this is not a must.

Which DPI value would you consider to be the correct value to be displayed in XnView?
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Troken
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Post by Troken »

helmut wrote:Vector graphics like PDF or AI consist of vectors, not pixels, so there is no such thing as DPI. PDF may contain an bitmap image, but this is not a must.

Which DPI value would you consider to be the correct value to be displayed in XnView?
If you ask me, this is a complex matter. PDFs can come in many varyaties. Easiest would probably be not to display any DPI information. It would be better than the current 72 DPI value.

- A PDF without any bitmap-images (only vector-graphics) are DPI independent, they have an unlimited DPI. How do you describe it?
- A PDF with bitmap-images with different DPI-values could perhapps get the lowest DPI value, but is fairly confusing.
- The only PDF with a staight-forward value is a single bitmap-image, saved as a PDF, but these are not very common.[/list]

So whats the conclution? My suggestion, as mentioned above, is to not display any DPI info for PDFs. But I'd very much like opinions on this.