Re: [Gimp-user] feature request: alpha level
From: "Ofnuts" Sent: Monday, July 22, 2013 3:45 PM On 07/22/2013 09:34 PM, Daniel Hornung wrote: On Monday, 22. July 2013 08:38:00 Alex Vergara Gil wrote: Hello GIMP developers: I am working on a project where I need to set all pixels below a level as alpha channel, is there a quick way to achieve this? The level can be both set a priori or adjusted dinamically, the second way is prefered. Right now my workflow includes: 1. duplicate layer. 2. use color level in duplicate layer, in menu COLOR -> LEVEL. 3. add alpha mask to original layer 4. copy duplicate layer into the alpha mask of the original. 5. delete duplicate layer. 6. If result is not ok then return to 1. As you can see this workflow is a headache, specially point 6 which is often achieved. Any thoughts 1. Create a channel mask from the grayscale value. 2. On the channel mask, use the threshold tool. Voilà! +1 For step 2) you can also uses Levels, Curves or even Brightness/Contrast, to keep some intermediate values of opacity and achieve a smoother result. ___ Great! I don´t know this could be done so easily. Thanks! I have adapted my workflow now. 1. Decompose original image in whatever you want RGB, LHS, LAB or even grayscale. Then pick some channel. 2. Copy the selected channel into an alpha mask of the original image. 3. Use level tool in the mask (threshold is not good because it creates sharp edges, but Curves and brightness/Contrast are good choices also). With this workflow you can also set an alpha level on a specified channel! Thank you all ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list
Re: [Gimp-user] feature request: alpha level
On 07/22/2013 09:34 PM, Daniel Hornung wrote: On Monday, 22. July 2013 08:38:00 Alex Vergara Gil wrote: Hello GIMP developers: I am working on a project where I need to set all pixels below a level as alpha channel, is there a quick way to achieve this? The level can be both set a priori or adjusted dinamically, the second way is prefered. Right now my workflow includes: 1. duplicate layer. 2. use color level in duplicate layer, in menu COLOR -> LEVEL. 3. add alpha mask to original layer 4. copy duplicate layer into the alpha mask of the original. 5. delete duplicate layer. 6. If result is not ok then return to 1. As you can see this workflow is a headache, specially point 6 which is often achieved. Any thoughts 1. Create a channel mask from the grayscale value. 2. On the channel mask, use the threshold tool. Voilà! +1 For step 2) you can also uses Levels, Curves or even Brightness/Contrast, to keep some intermediate values of opacity and achieve a smoother result. ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list
Re: [Gimp-user] feature request: alpha level
On Monday, 22. July 2013 08:38:00 Alex Vergara Gil wrote: > Hello GIMP developers: > > I am working on a project where I need to set all pixels below a level as > alpha channel, is there a quick way to achieve this? The level can be both > set a priori or adjusted dinamically, the second way is prefered. Right now > my workflow includes: 1. duplicate layer. > 2. use color level in duplicate layer, in menu COLOR -> LEVEL. > 3. add alpha mask to original layer > 4. copy duplicate layer into the alpha mask of the original. > 5. delete duplicate layer. > 6. If result is not ok then return to 1. > As you can see this workflow is a headache, specially point 6 which is often > achieved. Any thoughts 1. Create a channel mask from the grayscale value. 2. On the channel mask, use the threshold tool. Voilà! -- Mein öffentlicher Schlüssel / My public key: 4096R/600ACB3B 2012-04-01 Fingerabdruck / Fingerprint: 9902 575B B9A0 C339 CFDF 250B 9267 CA6B 600A CB3B Runterladen z.B. bei/ Get it e.g. from: pgp.mit.edu, subkeys.pgp.net, pgp.uni-mainz.de, pool.sks-keyservers.net, ... signature.asc Description: This is a digitally signed message part. ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list
[Gimp-user] feature request: alpha level
Hello GIMP developers: I am working on a project where I need to set all pixels below a level as alpha channel, is there a quick way to achieve this? The level can be both set a priori or adjusted dinamically, the second way is prefered. Right now my workflow includes: 1. duplicate layer. 2. use color level in duplicate layer, in menu COLOR -> LEVEL. 3. add alpha mask to original layer 4. copy duplicate layer into the alpha mask of the original. 5. delete duplicate layer. 6. If result is not ok then return to 1. As you can see this workflow is a headache, specially point 6 which is often achieved. Any thoughts Alex ___ gimp-user-list mailing list List address:gimp-user-list@gnome.org List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list
