OK ... now at least I sort of understand it.
I was trying to reduce an overly blue image and attained confusion instead.
I suspect that your {2) "a" steepness, "b" steepness} will bring even
more confusion especially to new users.
At least I *think* I now understand what is going on. Thanks
David
On 13-10-22 12:44 PM, Sergey Astanin wrote:
> Hi David,
>
> I agree, that the labels do not explain exactly what the sliders do: they
> adjust steepness of a* and b* curves in Lab (and tooltips say just that).
> The labels were supposed to make the tool approachable by less technical
> users who don't know about Lab curves. But it's difficult to describe the
> effect of a* and b* steepness in a label...
>
> Moving sliders to the right doesn't change color balance, but increases
> saturation of both colors (green *and* magenta, blue *and* yellow). Moving
> sliders to the left desaturates both colors (green *and* magenta, blue
> *and* yellow). Those are the effects for a color-neutral image, the actual
> effect might be different. If an image is tinted blue, the effect is
> different: moving the first slider to the right is more like "saturate blue
> and magenta", rather than "saturate green and magenta". So color names are
> just a mnemonics to distinguish them, but it's not always a correct
> description. Referring to a* and b* steepness directly is more correct.
>
> Thinking again about it, I note that while blue corresponds to small and
> negative a* values, green corresponds to positive b* values. So reversing
> the order of colors for one of the labels makes sense to me. I suppose that
> changing "vs" to "and" may be helpful too: to indicate that we change a
> pair of opposing colors, not one of them at expense of the other.
>
> So I think that these two ways of labeling the sliders make sense:
>
> 1) "green and magenta", "yellow and blue"
> 2) "a* steepness", "b* steepness"
>
> I don't know if (1) is really a usability improvement, though I like it.
>
>
>
> On 21 October 2013 19:27, David Vincent-Jones <davi...@frontier.com> wrote:
>
>> 'green vs magenta' ... slider to left vs slider to right ... intuitive
>> 'blue vs yellow' ... slider to right vs slider to left ... UN-intuitive
>>
>> I suggest that the blue and yellow label names should to be reversed.
>>
>> David
>>
>>
>>
>>
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