[Gimp-user] Alpha channel and pixel transparency value
Hi Gimp-user, I'd like to know the transparency value of a pixel in Gimp. In PSP, when you run the cursor over a pixel it'll tell you the RGB and the alpha percentage. Can I get this information in Gimp? Thank you. -- __ DJ mailto: delphit...@yahoo.com ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Alpha channel and pixel transparency value
On Thu, Apr 16, 2009 at 9:50 AM, DJ delphit...@yahoo.com wrote: Hi Gimp-user, I'd like to know the transparency value of a pixel in Gimp. In PSP, when you run the cursor over a pixel it'll tell you the RGB and the alpha percentage. Can I get this information in Gimp? Have you looked at docs.gimp.org to find out the answer to some of these questions? Anyway, the 'Cursor' dockable does this. David ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Alpha channel and pixel transparency value
Hi DJ, On Thu, Apr 16, 2009 at 10:28 AM, DJ delphit...@yahoo.com wrote: It may not appear like it, but yeh. Sorry. I'm hitting PF1 all the time to get specific doc too. I do a google site search for terms too. I didn't quite know what you meant by Cursor dockable. So I checked Windows - Dockable Dialogs, and didn't see that terminology. A friend Eh, maybe it is called 'Pointer' dockable. I don't use GIMP in the English language, but Lojban. The menu item in question appears after Undo History and before Sample Points in the menu. http://docs.gimp.org/en/gimp-windows-show-dock.html http://docs.gimp.org/en/gimp-pointer-info-dialog.html I noticed that pressing Shift+F1 over the 'Pointer' menu item only gives the 'EEK! Missing help' page. This is probably a bug in the docs, since the relevant page does actually exist. I scrolled across the image. That checkbox option eluded me... Such an option is not available in GIMP. If you would like it, I suggest making a mockup and submitting it to gimp-brainstorm.blogspot.com. However, the Pointer dockable works fine for me for this purpose, on the rare occasions I need it. Do you have a good reason for replying only to me rather than the list? It makes the thread on the mailing list appear disjointed. Here, I use 'Reply to All' to reply to messages from mailing lists, and this is effective. David ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
[Gimp-user] alpha channel computation
Hello. I have a TGA image that is fully opaque. I want to introduce translucency to the image, making each pixel translucent according to how far away from black it is. If a pixel is originally black, it becomes fully opaque. If a pixel is originally white, it becomes fully transparent. If a pixel is 0x7f7f7f (gray) or 0xff007f (approximately halfway in brighness between dark and light), it becomes somewhere around half transparent (computed using diagonal of color cube). Is there an easy way to do this in GIMP? i can imagine writing a quickie computer program to do this for me, but I'm sure the easier way would be to convince GIMP to do this for me. Thanks. ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] alpha channel computation
Hi, On Thu, 2008-07-24 at 11:49 -0700, Nerius Landys wrote: Hello. I have a TGA image that is fully opaque. I want to introduce translucency to the image, making each pixel translucent according to how far away from black it is. If a pixel is originally black, it becomes fully opaque. If a pixel is originally white, it becomes fully transparent. If a pixel is 0x7f7f7f (gray) or 0xff007f (approximately halfway in brighness between dark and light), it becomes somewhere around half transparent (computed using diagonal of color cube). Is there an easy way to do this in GIMP? Easy. Just add a layer mask. In the dialog for creating the mask, choose to initialize the mask with Grayscale copy of layer. Now you already got almost what you want. You just need to invert the mask as you want white to be transparent and black to be opaque. Colors-Invert will do this. Now all you need to do is to apply the layer mask. Sven ___ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
Re: [Gimp-user] Alpha Channel
cedric wrote: I wonder why, when Opening or creating a document, there are only 3 color channel and then, when creatin a layer, the alpha is coming. What this stand for ? Cedric The bottom layer cannot be transparent, as far as I'm aware, so it does not have an alpha channel associated with it. You can still export transparent gifs and pngs though. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.7 - Release Date: 12/04/2005 ___ Gimp-user mailing list Gimp-user@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Alpha Channel
On Wed, Apr 13, 2005 at 03:57:56PM +0100, David Marrs wrote: cedric wrote: I wonder why, when Opening or creating a document, there are only 3 color channel and then, when creatin a layer, the alpha is coming. What this stand for ? Cedric The bottom layer cannot be transparent, as far as I'm aware, so it does not have an alpha channel associated with it. You can still export transparent gifs and pngs though. Err, unless I am misunderstanding you, you are wrong. Bottom layers can most definitely be transparent. As noted previously in response to this question, when you create a new image, what you fill the base layer with changes whether or not it has an alpha channel. At any point, you can add an alpha channel by going to: Layer - Transparency - Add Alpha Channel At any point, you can remove an alpha channel by flattening the layer. Jeff -- Computer Science is as much about computers as astronomy is about telescopes -- Edsger Wybe Dijkstra (1930-2002) pgpP6G9fLk27B.pgp Description: PGP signature
Re: [Gimp-user] Alpha Channel
Jeffrey Brent McBeth wrote: On Wed, Apr 13, 2005 at 03:57:56PM +0100, David Marrs wrote: cedric wrote: I wonder why, when Opening or creating a document, there are only 3 color channel and then, when creatin a layer, the alpha is coming. What this stand for ? Cedric The bottom layer cannot be transparent, as far as I'm aware, so it does not have an alpha channel associated with it. You can still export transparent gifs and pngs though. Err, unless I am misunderstanding you, you are wrong. Yup, sorry. I should know that, having made bottom layers transparent in the past! (wtf?) I don't know where I got that from. Put it down to lack of coffee. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.7 - Release Date: 12/04/2005 ___ Gimp-user mailing list Gimp-user@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Alpha Channel Continuing.
OK. Understood. But i think something is quite strange (it's UI, only). Alpha Channel is displayed in the upper part of the window. I thought this part was made for permanent informations (such as primary channels), but it seems that the alpha is dealing only with the active layer. Does anybody have an explanation of that behavior ! Cedric ___ Gimp-user mailing list Gimp-user@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
[Gimp-user] Alpha Channel
I wonder why, when Opening or creating a document, there are only 3 color channel and then, when creatin a layer, the alpha is coming. What this stand for ? Cedric ___ Gimp-user mailing list Gimp-user@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Alpha Channel
On Wed, 2005-04-13 at 01:47 +0200, cedric wrote: I wonder why, when Opening or creating a document, there are only 3 color channel and then, when creatin a layer, the alpha is coming. What this stand for ? The default setting for a new document is the RGB colorspace with the document filled with the background color; no transparency is needed. When you add a layer, if you change nothing, the layer will be transparent, so an alpha channel is required at that point and one will be added. You can set up a new document to have the background filled with transparency (under the advanced options tab in the new image dialog box) and then you will have an alpha channel from the start. However, if you create a new layer filled with the background or foreground color, that will still add an alpha channel if you do not have one in the image, because there are always transparency options available for layers. Cheers, Malcolm ___ Gimp-user mailing list Gimp-user@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Alpha Channel
Hi, Paulo S [EMAIL PROTECTED] writes: I am a novice user of GIMP and I would like to understand Alpha Channel. Could somebody here please help me? Perhaps some of these links can help: http://kimihia.org.nz/how/gimpalpha/ http://gug.sunsite.dk/faq.php?cat=1 http://gimp-savvy.com/BOOK/node56.html Sven ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Alpha Channel
Perhaps some of these links can help: http://kimihia.org.nz/how/gimpalpha/ http://gug.sunsite.dk/faq.php?cat=1 http://gimp-savvy.com/BOOK/node56.html Thanks a lot, Sven! Paulo ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
