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Does bicubic zoom some .gif V 1.95.2 1.95.3 1.95.4

Posted: Sun Nov 30, 2008 7:03 pm
by Jou
The example picture where xnview does the perfect resampling (bicubic or whatever) when enlarging the picture:
http://www.sinfest.net/archive_page.php?comicID=1935
And just one day later an example of an image where xnview does only cheap pixel resize.
http://www.sinfest.net/archive_page.php?comicID=1936

Go about fifty pictures backwards and you will have many examples for .gif files which resize nicely.

Go about fifty pictures forward and you have enough .gif files which xnview only displays with cheap pixel resize.

Is this a bug in xnview ? I think so, but I want others to confirm what I see.

Jou

Posted: Sun Nov 30, 2008 10:45 pm
by XnTriq
If you take a look at the color maps (Image » Edit Palette...) of 2005-08-01.gif & 2005-08-02.gif, you'll find out that one is based on a grayscale palette (all 256 unique shades of gray are used in the picture) while the other has a web-safe palette (only 6 out of 216 colors are used).

Recommended workaround: Increase the images' color depth from 8- to 24-bit (Image » True Colour) or convert them to grayscale (Image » Convert to Grey » 256 Grey scale).

Posted: Mon Dec 01, 2008 8:24 pm
by Jou
Ah, thank you for clearing the difference between those two, I missed that spot.

So this does make a bug in xnview for treating them different, they should both be bicubic resized (at least from my point of view).

Jou