Wikipedia:Reference desk/Archives/Computing/2016 September 24

= September 24 =

Y Matching Paint Tool
I used to have a program, like paint, that, when you selected a colour, could match the luma of any point you drew. Essentially, it would change the colour, but keep the shading. I cannot figure out what program this was, if you know of any programs that can do this, it would be wonderful. I need to recolour a bunch of sprites for a game I'm working on, it is very tedious doing it without this. Thank you for any help:-) Phoenixia1177 (talk) 00:31, 24 September 2016 (UTC)


 * You mean the luminosity in the Hue-Saturation-Luminosity model ? I should think any number of programs would do that.  StuRat (talk) 01:22, 24 September 2016 (UTC)
 * You are correct, the draw and paint tools matched the y in yuv. Do you know of any programs that can do this easily, preferably free ones.72.23.145.236 (talk) 01:27, 24 September 2016 (UTC)
 * ImageMagick, but it's command-line only. Here are example invocations to change the H,S and L channels individually Asmrulz (talk) 03:09, 24 September 2016 (UTC)
 * I think I'm poorly explaining what I'm looking for. You know how you can pick the pencil in mspaint and draw with it? In this program, you could do the exact same thing, select Y matching, then, if you click on a pixel it will change it to the colour selected, but keep the luma the same. So, for example, if you had the colour green selected and clicked on a pink pixel, it would turn it to a green pixel with the same brightness as it had when pink. In short, this made recolouring sprites easier since you could change the colour of the hair without having to worry about how bright each pixel was, you just picked a colour and applied it, pixel by pixel.73.174.196.36 (talk) 03:16, 24 September 2016 (UTC)
 * I found it, Ultimate Paint has this feature as part of its fill dialogue.73.174.196.36 (talk) 03:38, 24 September 2016 (UTC)

email addresses on Apple 'Mail'
I have a number of different addresses and want to close/remove them so that I do not receive mail sent to those addesses, how do I do that please? Artjo (talk) 13:26, 24 September 2016 (UTC)
 * Are you looking to close the email boxes completely with their constituent services, if so, you would go to those services and request to close your account. If you simply want to delete the accounts from Mail in macOS, go to SYSTEM PREFRENCES → INTERNET ACCOUNT. You will be able to delete or adjust your email account settings there.--Adam in MO Talk 21:41, 25 September 2016 (UTC)

Thanks for this but it is not accounts that I want to delete but the one or two of the many email addresses that I have created over the years. Any ideas please?Artjo (talk) 21:53, 26 September 2016 (UTC)

Permissions expressed in code
I've noticed that two software platforms that use permissions, a model of security that seems to be taking off, don't use plain labels to mark the, but instead use language objects or classes to signify them. I'm talking about Android and Java. These permissions are associated with source code, but I don't get how expressing the permissions in the code that is managed by a runtime works or why it is necessary. How does the inclusion of a permission's class in a program provide security when anyone can just include it in their code? More over, how does that relate to the runtime that monitors what an application does to sandbox it with a particular set of permissions? — Melab±1 &#9742; 20:23, 24 September 2016 (UTC)
 * That's odd. Such an interesting Q, and no answers. I'll just venture a guess and say that, while nothing stops you from trying to create any permission object, or declaring permissions you want in the manifest file, the runtime will signal an exception if you don't actually have that permission. Asmrulz (talk) 09:52, 26 September 2016 (UTC)


 * >> . How does the inclusion of a permission's class in a program provide security when anyone can just include it in their code?
 * Inclusion of permission's class in program allows programmer to access related class/library functions. When such program is installed on device, these used/requested permissions are listed and user has option to allow or deny any or all of these permission. When program runs and attempts to do anything that is not allowed by user, the run-time system does not allow program to execute it and throws error. manya (talk) 05:33, 27 September 2016 (UTC)