Clarification on the use of the terms 'Brightness' and 'Luminosity'

[Boudhayan Gupta]

Hi Valter,

There's two answers to this question. The first is that at least as far as
physics is concerned, luminosity and brightness are two different things.
Luminosity is the amount of luminous radiation emitted by the object as
measured from the position of said object in space, and brightness is not a
physics term at all, but most closely relates to luminance, which is
luminous intensity per unit area, as measured at the point of observation.

In the context of computer graphics, brightness really literally means how
bright the image looks (how darkened or brightened it is), while luminosity
is a component of the HSL way of defining colours
(Hue/Saturation/[Lightness,Luminance,Luminosity]). Unfortunately the terms
are really used interchangeably, and some programs even use HSB
(Hue/Saturation/Brightness).

I hope this helps.

Thanks,
Boudhayan


On Wed, 3 Jun 2020 at 22:32, Valter Mura <valtermura at gmail.com> wrote:

> Hi,
>
>
>
> My name is Valter Mura and I work in the KDE Italian Localization Team and
> I'm translating Krita in Italian.
>
> I have a question concerning the use of two (similar) nouns in the
> program:
>
> *Brightness* and *Luminosity*
>
>
>
> Is there any specific reason to use one noun in one place instead of the
> other noun?
>
>
>
> Can we consider them synonyms?
>
>
>
> Are there very special cases for the use of "Brightness" in some parts and
> "Luminosity" in others?
>
>
>
> Thanks for the attention.
>
> Please keep me in CC, I'm not subscribed to this list.
>
> Best regards,
>
> --
>
> Valter
>
> Open Source is better!
>
> LibreOffice: www.libreoffice.org
>
> KDE: www.kde.org
>
> Kubuntu: www.kubuntu.org
>
> KDE neon: https://neon.kde.org/
>
> La bici non consuma e non produce emissioni, non ingombra e non fa rumore:
>
> è un mezzo ecologico per definizione e ad alta efficienza energetica.
>
> La bicicletta migliora il traffico, l'ambiente, la salute e l'umore.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.kde.org/pipermail/kimageshop/attachments/20200604/b76abddc/attachment.htm>