Not sure if it is something like rounding errors:
Search found 188 matches
- 2012-08-15T09:42:27-07:00
- Forum: Bugs
- Topic: Resizing pictures with sharp B/W lines under LUV
- Replies: 13
- Views: 19284
- 2012-08-15T05:07:05-07:00
- Forum: Bugs
- Topic: Resizing pictures with sharp B/W lines under LUV
- Replies: 13
- Views: 19284
Resizing pictures with sharp B/W lines under LUV
Win32 ImageMagick 6.7.8-10 2012-08-10 Q16 DLL convert rings_lg_orig.png -colorspace LUV -resize 25% -alpha off +repage -colorspace sRGB -quality 95% rings_sm_luv1.png convert rings_lg_orig.png -set colorspace sRGB -colorspace LUV -resize 25% -alpha off +repage -colorspace sRGB -quality 95% rings_sm_...
- 2012-08-13T10:03:10-07:00
- Forum: Digital Image Processing
- Topic: "Sigmoidal" minimization of resampling filter haloing & blur
- Replies: 136
- Views: 341182
Re: "Sigmoidal" minimization of resampling filter haloing &
Me neither, especially after Anthony's comment that while linear RGB's intensity is linear, its colors are not.NicolasRobidoux wrote:I am convinced that linear light is "it" when downsampling. But I am not certain.
- 2012-08-12T23:02:23-07:00
- Forum: Digital Image Processing
- Topic: "Sigmoidal" minimization of resampling filter haloing & blur
- Replies: 136
- Views: 341182
Re: "Sigmoidal" minimization of resampling filter haloing &
I wonder how much these contrived tests really tell us. Sorry being off-topic. Actually I should have posted in another thread where Anthony talks about LAB and LUV. Even if they are too harsh sometimes, these contrived tests do help revealing abnormality. For example, the LUV-downsize above produc...
- 2012-08-12T17:30:57-07:00
- Forum: Digital Image Processing
- Topic: "Sigmoidal" minimization of resampling filter haloing & blur
- Replies: 136
- Views: 341182
Re: "Sigmoidal" minimization of resampling filter haloing
Henry: "Brasseur test" conclusion: stick to linear light when downsampling. Seems LUV works very well in Brasseur-Dalai test: convert gamma_dalai_lama_gray_tft.jpg -distort resize 50% -quality 95% -sampling-factor 1:1:1 dal_tft.jpg convert gamma_dalai_lama_gray_tft.jpg -set colorspace sRG...
- 2012-08-12T08:03:05-07:00
- Forum: Digital Image Processing
- Topic: [SOLVED] making sense of sigmoidal-contrast
- Replies: 38
- Views: 90689
Re: making sense of sigmoidal-contrast
Hope we will have an official HDRI compile.NicolasRobidoux wrote:When I have a minute, I will change enhance.c so that sigmoidal-contrast not use a LUT in HDRI mode
- 2012-08-12T07:56:35-07:00
- Forum: Users
- Topic: PNG resize question
- Replies: 6
- Views: 10247
Re: PNG resize question
It works again by adding "-set colorspace sRGB".
Code: Select all
convert rings_lg_orig.png -alpha off -set colorspace sRGB -colorspace RGB -filter RobidouxSharp -distort resize 50% -colorspace sRGB -alpha off +repage -quality 95% test1b.png
- 2012-08-11T06:54:29-07:00
- Forum: Users
- Topic: PNG resize question
- Replies: 6
- Views: 10247
Re: PNG resize question
With 6.7.8-9 Win64 DLL, gray images appear to be causing troubles again: convert rings_lg_orig.png -alpha off -colorspace RGB -filter RobidouxSharp -distort resize 50% -colorspace sRGB -alpha off +repage -quality 95% test1.png convert rings_lg_orig.png -alpha off -evaluate POW 2.2 -filter RobidouxSh...
- 2012-08-10T09:49:03-07:00
- Forum: Users
- Topic: Summary: reducing (downsizing) natural images
- Replies: 4
- Views: 8753
Re: Summary: reducing (downsizing) natural images
A small note that some ppls like to take BW (gray) photos but IM6 behaves weirdly with gray photos and -colorspace options. Better use -gamma with gray photos for the time being.
- 2012-08-10T09:39:22-07:00
- Forum: Users
- Topic: Summary: reducing (downsizing) natural images
- Replies: 4
- Views: 8753
Re: Summary: reducing (downsizing) natural images
Are "LanczosRadiusN" and "LanczosSharpestN" available directly in IM6 or 7 now?
- 2012-08-09T18:05:48-07:00
- Forum: Users
- Topic: PNG resize question
- Replies: 6
- Views: 10247
Re: PNG resize question
r u really upsizing by 1000 times?
- 2012-08-08T03:58:05-07:00
- Forum: Digital Image Processing
- Topic: "Sigmoidal" minimization of resampling filter haloing & blur
- Replies: 136
- Views: 341182
Re: "Sigmoidal" minimization of resampling filter haloing
Henry: I'll have to redo the downsampling tests with the newly fixed sigmoidal-contrast code. (IM7 is closest to fixed, and the fix is not complete for orthogonal resize methods with negative lobes.) Other things to do for a while. Remember to include this test case: http://www.4p8.com/eric.brasseu...
- 2012-08-07T01:00:10-07:00
- Forum: Users
- Topic: PDF to JPG – Trying to obtain a “Crisp” (not fuzzy) JPG
- Replies: 6
- Views: 17359
Re: PDF to JPG – Trying to obtain a “Crisp” (not fuzzy) JPG
To add even more acutance (sth like edge sharpness), convert -density 288 image.pdf -filter lagrange -distort resize 25% -quality 95 -sampling-factor 1:1 image.jpg Linear RGB resize is mathematically more correct but this is probably counter-productive in this use case: convert -density 288 image.pd...
- 2012-07-26T18:46:16-07:00
- Forum: Digital Image Processing
- Topic: future of image enlargement?
- Replies: 61
- Views: 159712
Re: future of image enlargement?
Hey, it's not fair. I am an amateur using defaults and you are THE expert using tuned parameters.
- 2012-07-26T09:50:14-07:00
- Forum: Digital Image Processing
- Topic: future of image enlargement?
- Replies: 61
- Views: 159712
Re: future of image enlargement?
Pure NNEDI3NicolasRobidoux wrote:Thank you Henry.henrywho wrote:...
Let me try Avisynth+NNEDI3+EEDI3 tonight.