I had a nightmare

[Radiance]

strange, i think i missed saving a layer in photoshop then, i had propper crosses on the line for blue and green

i'll resave/upload the image...

EDIT: haha, it's due to the missing antialiasing in downscaled images on the forum, just click to view the image in full and you'll see the lines lol

Radiance

[Lord Crc]

The paper mentions staying on the line 2C + B = 1, in the interval B = 0 to 5/3, so this could be used for a simple slider, along with some presets (or just presets).

[Radiance]

hmmmm,

that's not a bad idea, i'll see if i can add a slider in luxblend.
then we can render some comparisons and pick a good default and some presets

Radiance

[Radiance]

Hey,

I added a mode to the luxblend mitchell options, where you have the old B and C params when you choose 'manual',
or 'preset' and 'slider'.

The slider is implemented and goes from 0 (blurry) to 1 (sharp) which is basically a linear measure which follows the dotted line in the graph.

I think the current default is a bit too much, maybe we should aim for something along the 0.3 (B=0.7/C=0.15) as the default ? or 0.35 ?

greetz,
Radiance

[Radiance]

This one cooked last night with 0.35, and it seems good, no ringing and to me it looks acceptable in terms of blurryness...

I'll code it into luxblend as the default for now.

Radiance

[Lord Crc]

Yeah looks good to me too.

[jim]

To revive the off-topic part of an old thread...

I was doing some other work, and ran across the following link which I think is extremely useful as a technical (but not mathematical) introduction to image filtering, including some examples...
http://www.imagemagick.org/Usage/resize/#filter

Also of interest is that ImageMagick now supports EXR images, which could make it exceedingly useful for Lux.