Legacy ImageMagick Discussions Archive

I wanna try testing with this concept. Using the sample image at http://forums.dpreview.com/forums/read.asp?forum=1006&message=40282142 the anti-aliasing effect seems not easily noticeable. convert.exe 7640_CO40_FM1-175pct_sRGB.jpg -colorspace RGB -filter RobidouxSharp -distort resize 1800x900! ...

Do you have any tool to demosaic the RAW samples at
http://www.fotopolis.pl/index.php?n=14580&p=1

P.S. The landscape sample seems nice (http://www.dpreview.com/reviews/nikon-d800-d800e/27)

"-q 1" is VNG ... um....

http://www.libraw.org/articles/bayer-moire.html

Perhaps rawtherapee with LMMSE or AMaZE using "neutral" BW? It seems to have linux binary distributions.

Actually, the color of "apartment.tif" is a bit off, kinda green-cast there. What something like: LibRaw-0.14.6\bin\dcraw_emu.exe -w +M -H 2 -fbdd 1 -dcbe -q 10 -o 1 -g 1 1 -6 apartment.rw2 ImageMagick\convert.exe apartment.rw2.ppm -set colorspace sRGB -crop 2520x2520+530+1249 +repage -def...

That "whitepaper" is for marketing guys, nothing technical

I tend to believe that they are re-using the quick resample routine (the one for realtime display and "pureview" digital zoom) for that "oversampling" task, giving the sub-par results.

[duplicate post deleted]

Conjecture With my favorite methods, no negative total weight can occur. as long as that there is no programming or compiler bugs (or different rounding conventions, etc.) 8) btw, though not DSLR, Nokia is introducing a 41MP mobile phone with a 1/1.2" sensor. :shock: Information and samples at...

ImageMagick seems to be converting raw files with the bundled dcraw 9.06 which is a bit too old.

You may want to take a look at the dcraw "clone" in LibRaw (http://www.libraw.org/download) which has more demosaic and denoise methods.

But if what you say is true, why not use an even more extreme gamma change on both ends rather than just the .45455 and inverse built into sRGB? Does that make any sense? I just find linear light downsize produces images that match better (brightness wise) to viewing the original 1:1 image a few fe...

In my testes, images with heavy PP(post processing) have a tendency to be worst when using linear light due to the fact that the PP may already have enhanced the details... I tend to take a simpler explanation. Artifacts are unwanted patterns formed by interpolated values generated by resizers. The...

Pictus wrote:convert BackPack.png -filter Lanczos -define filter:lobes=4 -define filter:blur=0.88451002338585141 -resize 1200x1200 Lanczos_4.png
....

Aren't these blur values designed for distort resize?

NicolasRobidoux wrote:Do you see problems with the downsample of the apartments image I put in the test image bank? If you do (please explain), I may redo it.

No, it's the image itself, containing high contrast sharp lines. I tried sizing it down by 50% and then up by 2X, the lines become awful.

Pictus wrote:use some contrast detect algorithm to choose the good one...

I think the range from EWA-Robidoux to EWA-Catrom should cover most uses.

P.S. I just checked: Indeed box filtering by 3 of a crop to multiples of 3 in both directions shows moire. I'm really happy now that none of the images in the test image bank I prepared is moire prone. But apartment.tif is alias-prone. 8) P.S. 2 Henry, I am truly very thankful for all your feedback...

I remember that cubic calculation are quite a bit faster than, e.g. Jinc, for EWA, right? The time needed for such search should be acceptable. Indeed, the sharper the source, the less sharp the downsizer should be. If we have some algorithm to evaluate the sharpness, can we have some automatic calc...