Search found 188 matches
- 2013-03-29T22:07:44-07:00
- Forum: Bugs
- Topic: [solved] Lab: "a" &" b" leaking into L in RGB round-trip?
- Replies: 11
- Views: 19958
Re: LAB: A&B channels leaking into L?
That is correct. (Except that they are called a and b, not A and B.) And I thought "fully saturated" have different implications in "Lab" and "RGB". Under "Lab", no matter how we manipulate "a" and "b", "L" should not be affected...
- 2013-03-29T20:10:33-07:00
- Forum: Bugs
- Topic: [solved] Lab: "a" &" b" leaking into L in RGB round-trip?
- Replies: 11
- Views: 19958
Re: LAB: A&B channels leaking into L?
I thought A and B control the "hue" and "saturation" only... having no effect on luminance.
- 2013-03-29T18:27:23-07:00
- Forum: Bugs
- Topic: MinGW / Windows distribute-cache.c build err
- Replies: 5
- Views: 7141
Re: MinGW / Windows distribute-cache.c build err
Awesome, thanks! By the way, can you give the steps you use to build on MinGW + windows? I was having some issues due to pthread and such (which I ironed out using the pthread for windows port) but I want to check if there is a better / easier way I once worked out a way to compile it under mingw32...
- 2013-03-29T15:30:15-07:00
- Forum: Bugs
- Topic: [solved] Lab: "a" &" b" leaking into L in RGB round-trip?
- Replies: 11
- Views: 19958
[solved] Lab: "a" &" b" leaking into L in RGB round-trip?
Found something strange.... convert.exe -respect-parentheses \ rose: -set colorspace sRGB -colorspace LAB \ -channel R -separate placebo_%d.png convert.exe -respect-parentheses \ rose: -set colorspace sRGB -colorspace LAB \ -channel G -sigmoidal-contrast 9,50% \ -channel B -sigmoidal-contrast 9,50% ...
- 2013-03-28T10:13:41-07:00
- Forum: Users
- Topic: Alternative to modulate command to increase Saturation
- Replies: 40
- Views: 65613
Re: Alternative to modulate command to increase Saturation
If it is a problem of "-separate", "b_0.png" should have been fine.
but "b_0.png" is wrong (in the same way) even if I put "RGB", "LUV", "HCL", etc. in place of "sRGB" in the middle.
but "b_0.png" is wrong (in the same way) even if I put "RGB", "LUV", "HCL", etc. in place of "sRGB" in the middle.
- 2013-03-28T05:56:35-07:00
- Forum: Users
- Topic: Alternative to modulate command to increase Saturation
- Replies: 40
- Views: 65613
Re: Alternative to modulate command to increase Saturation
@henrywho: if you want to increase saturation while leaving the L of Lab unchanged, the obvious way is to do it in Lab space. The a and b channels both record saturation as the distance from 0.5, that is a=b=0.5 (in the range 0 to 1) represents zero saturation. So apply the same "-sigmoidal-co...
- 2013-03-27T21:44:37-07:00
- Forum: Bugs
- Topic: L in HCL is not Luminance! (my error)
- Replies: 11
- Views: 20774
Re: L in HCL is not Luminance!
I am using Win32 Q16 static compile: Version: ImageMagick 6.8.3-5 2013-02-24 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2013 ImageMagick Studio LLC Features: DPC OpenMP convert.exe rose: -set colorspace srgb -colorspace hcl -channel R -gamma 1 +channel -colorspace lab -channel R -s...
- 2013-03-27T05:18:53-07:00
- Forum: Users
- Topic: Alternative to modulate command to increase Saturation
- Replies: 40
- Views: 65613
Re: Alternative to modulate command to increase Saturation
Actually, I am trying to increase the saturation so "-gamma 1.5" seems more appropriate.... except that I am looking for a way not to touch the pixels with high saturation.... something like "if saturation > threshold then untouch else increase it". Looking for some simpler way o...
- 2013-03-26T22:03:09-07:00
- Forum: Users
- Topic: Alternative to modulate command to increase Saturation
- Replies: 40
- Views: 65613
Re: Alternative to modulate command to increase Saturation
Just tried something like:
convert.exe input.png -set colorspace srgb -colorspace hcl -channel G +sigmoidal-contrast 3.5,49% +channel -colorspace srgb output.png
Not bad.... but I need something asymmetric so as not to de-saturate the high-saturation areas. Do u guys have any idea?
convert.exe input.png -set colorspace srgb -colorspace hcl -channel G +sigmoidal-contrast 3.5,49% +channel -colorspace srgb output.png
Not bad.... but I need something asymmetric so as not to de-saturate the high-saturation areas. Do u guys have any idea?
- 2012-12-11T23:15:20-07:00
- Forum: Digital Image Processing
- Topic: 5 new interpolation kernels
- Replies: 10
- Views: 29259
5 new interpolation kernels
For whoever interested, *.mp4 has posted five interpolation kernels in Doom9:
http://forum.doom9.org/showthread.php?t=166080
http://forum.doom9.org/showthread.php?t=166080
- 2012-12-01T09:12:24-07:00
- Forum: Users
- Topic: Oriental languages Japanese, chinese, Korean, etc
- Replies: 3
- Views: 7043
Re: Oriental languages Japanese, chinese, Korean, etc
try specifying a font like Arial Unicode MS or PMingLiU
- 2012-11-20T19:00:44-07:00
- Forum: Users
- Topic: Resizing working very slow
- Replies: 7
- Views: 12176
Re: Resizing working very slow
Agreed with fmw42.
A sharpened JPEG saved at a lower quality may have similar size as a smoother JPEG saved at a higher quality.... but looking much worse.
A sharpened JPEG saved at a lower quality may have similar size as a smoother JPEG saved at a higher quality.... but looking much worse.
- 2012-11-20T17:33:52-07:00
- Forum: Developers
- Topic: getting rid of Windows registry entries
- Replies: 2
- Views: 6804
Re: getting rid of Windows registry entries
Or search in the following order:
1) same directory or specific subdirectory of convert.exe/magick.exe
2) environmental variable (e.g. MAGICK_CONFIGURE_PATH)
3) HKCU
4) HKLM
1) same directory or specific subdirectory of convert.exe/magick.exe
2) environmental variable (e.g. MAGICK_CONFIGURE_PATH)
3) HKCU
4) HKLM
- 2012-11-20T17:27:33-07:00
- Forum: Users
- Topic: Resizing working very slow
- Replies: 7
- Views: 12176
- 2012-11-16T22:44:17-07:00
- Forum: Digital Image Processing
- Topic: Resize and resample in alpha-multiplied light
- Replies: 5
- Views: 106941
Re: Resize and resample in alpha-multiplied light
Last week I was resampling some large web banners (with transparency) into small paletted (8bit) icons. I also ended up with flatten-then-resample: convert big_banner_with_alpha.png -set colorspace srgb +repage \ -colorspace lab -background white -flatten \ -define filter:window=Quadratic -define fi...