Ok, what I probably need is to scale one channel with scale factor increasing gradually from left to right, and do the opposite for the other two channels.
Of course you are right regarding desaturation of a single channel being nonsense.
Search found 37 matches
- 2013-09-22T04:13:20-07:00
- Forum: Users
- Topic: Gradient desaturation?
- Replies: 14
- Views: 8277
- 2013-09-22T03:59:54-07:00
- Forum: Users
- Topic: Gradient desaturation?
- Replies: 14
- Views: 8277
Re: Gradient desaturation?
I would attach a sample input image, but seems like the forum infrastructure doesn't support that.
I _think_ gradual desaturation is what I want; cannot be 100% sure of course.
I _think_ gradual desaturation is what I want; cannot be 100% sure of course.
- 2013-09-21T06:23:56-07:00
- Forum: Users
- Topic: Gradient desaturation?
- Replies: 14
- Views: 8277
Gradient desaturation?
Is it possible to gradually desaturate color channels in an image? E.g. I have a red-cyan anaglyph that shows over-saturation of cyan towards the left side and over-saturation of red towards the right side. I'd like to extract the green+blue channels and desaturate them with something like min:max w...
- 2013-08-31T07:28:04-07:00
- Forum: Users
- Topic: Removing complex vighetting
- Replies: 7
- Views: 8163
Re: Removing complex vighetting
Ok, here is the solution I adopted. The idea is to use Plus and Minus operators sequentially instead of fx operator. I start with a photo of the (undesired) vignette when impact I want to compensate. It's neutral in the center and has color casts growing towards sides. I make a one-color image with ...
- 2013-08-17T05:26:39-07:00
- Forum: Users
- Topic: Removing complex vighetting
- Replies: 7
- Views: 8163
Re: Removing complex vighetting
So, I downloaded Fred's HDR-enabled IM from . ====== D:\Photo\SL3D_35_2d8\TRY>convert -version Version: ImageMagick 6.7.6-1 2012-03-17 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC Features: HDRI ====== But my -fx "u+v.p{w/2,h/2}-v" command still ...
- 2013-08-16T23:30:01-07:00
- Forum: Users
- Topic: Removing complex vighetting
- Replies: 7
- Views: 8163
Re: Removing complex vighetting
Thanks! Regarding the version: I started with the latest - ImageMagick-6.8.6-8, but the fx operator didn't work. I then switched to ImageMagick-6.7.1-6 and found the same problem. The reason: fx expects expression in double quotes, while the examples use single quotes. My platform is Windows, which ...
- 2013-08-16T13:19:50-07:00
- Forum: Users
- Topic: Removing complex vighetting
- Replies: 7
- Views: 8163
Removing complex vighetting
I'm experimenting with single-lens 3D photography; this technique introduces heavy color vignetting. E.g. the closer you are to the left, the stronger is cyan cast; the closer you are to the right, the stronger is red cast. I'm trying to fix this by subtracting a photo of white wall (ColorVign_dark_...