In article <22icav4v4rfsmsaue3rbijffon1g935u3h@4ax.com>,
 Peter Popov <pet### [at] vipbg> wrote:

> Disagreed. Perhaps you're confusing blur with mosaic here? Mosaic does
> wonders with nearest neighbor, if you scale down by an integer factor
> and use the same number for the mosaic size. Thus you get the exact
> same result as +a0.0 +rn, where n is the scale factor.

No, I am thinking of blur. (How could I confuse it with mosaiac?!?)
And mosaiac will only "do wonders with nearest neighbor" if it does just 
what the resampling algorithm would do anyway. What you suggest here is 
equivalent to downsampling with some good algorithm, upsampling back to 
the original size with nearest neighbor, and then downsampling again 
with nearest neighbor. You also assume mosaiac itself doesn't use 
nearest neighbor.


> Gaussian blur helps a lot in most other downsampling algorithms, with
> the slight drawback that some careful work with unsharp mask is need
> after the resizing to bring out the (now) subpixel details.

And this can all be handled by the downsampling algorithm itself, in 
which case you will just be doing more work than necessary at best, or 
get in its way and get inferior results at the worst. A good algorithm 
will sample the area around the destination pixel, if the source image 
is blurred you will get bleed over in the final image. The resulting 
image will be blurrier than it should be.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/

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