[reportlab-users] drawImage makes image roughly twice as big as it should be

[JP Glutting]

Thanks! That was a very informative post.

Tim Roberts wrote:

>On Thu, 26 Jan 2006 08:34:48 +0100, JP Glutting <jpglutting at oqua.udl.es>
>wrote:
>
>  
>
>>Thanks. I ended up just using a much larger image, and it scales down 
>>well - it just takes up a lot more space in the document.
>>
>>    
>>
>
>Yes.  It NEEDS to.  Your smaller image doesn't have enough pixels to
>render properly on anything but a web site.
>
>  
>
>>The drawImage 
>>function maps one point to one pixel by default: "If width and height 
>>are not given, the "natural" width and height in pixels is used at a 
>>scale of 1 point to 1 pixel."
>> 
>>
>>    
>>
>
>Right.  What that means is that a 101x75 pixel image will occupying a
>rectangle of 101 points by 75 points.  If you happen to view that file
>at 100% magnification on a device that has a resolution of 72 pixels per
>inch, then it will look as you expect.  Most Windows displays are set
>for either 96 dpi or 120 dpi.  Plus, you were probably viewing your PDF
>at a magnified view.
>
>PDF files don't work in pixels, ever.  Everything is in real-world
>physical units, even when they are displayed on a CRT.
>
>  
>
>>Unfortunately, I can't create my own logo, since it is the official logo 
>>of the university, and I am not handy enough to re-create it, but I will 
>>try to get a copy in EPS format.
>> 
>>
>>    
>>
>
>If the higher-res JPEG is acceptable, then there is probably no need to
>look for an EPS.
>
>  
>
>>To clarify - I understand what you are saying about the printer, but the 
>>problem was that the image was magnified and looked bad in the Adobe, 
>>before it even went to the printer.
>> 
>>
>>    
>>
>
>Right.  There's no real difference between the two.  The screen happens
>to have a lower resolution than the printer, but it's still higher than
>the 72 dpi resolution you get with the default 1 point : 1 pixel setup,
>so it gets stretched.
>
>  
>


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