[Radiance-general] aspect ratio problem

[Gregory J. Ward]

Hi Iebele,

If you have a specific pixel aspect ratio, ra_tiff preserves this  
information in it's horizontal/vertical density tags.  If your  
application doesn't understand or interpret these tags, your image  
won't be displayed correctly.  Oddly enough, Photoshop doesn't  
correct the aspect ratio on display.  Photosphere does, as does  
Preview.  I don't know what tool you are using when you say that the  
aspect ratio is lost in the TIFF.

-Greg

> From: iebele <info at iebele.nl>
> Date: September 7, 2006 5:45:54 AM PDT
>
> Hi Lars,
>
> Thanks for your suggestion using image aspect ratios instead of  
> pixel aspect ratios.
>
> Anamorpic Pal is (as I understood) a 720x576 image stretched to  
> 1024x576 by the displaying device.
> This suggests a pixel of which width is 1.42 taller as its height.
>
> I tried your suggestion and rendered my image at 1024x576 square  
> pixel with a the vv value calcualted like this:
> vv = vh / 1.42  (where 1.42 is 1024/720 )
>
> Rendering square pixels at 1024x576 works fine, at least the image  
> fits the videoframe.
> But I really wonder if the way I calculated the vv value is correct.
>
> -Iebele
>