[Kdenlive-devel] Color correction tools: How and where to implement them?

[Simon Eugster]

2010/7/30 Till Theato <root at ttill.de>:
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> On 07/15/2010 10:21 PM, Simon Eugster wrote:
>> 2010/7/15 Dan Dennedy <dan at dennedy.org>:
>>> On Thu, Jul 15, 2010 at 1:49 AM, Till Theato <root at ttill.de> wrote:
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>>>> On 07/15/2010 09:52 AM, Simon Eugster wrote:
>>>>> 2010/7/14 Till Theato <root at ttill.de>:
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>>>>>> On 07/14/2010 07:13 PM, Dan Dennedy wrote:
>>>>>>> On Wed, Jul 14, 2010 at 9:00 AM, Simon Eugster <simon.eu at gmail.com> wrote:
>>>>>>>>>> * 3-Way color correction works basically quite well,
>>>>>>>>>>   but the usability is terrible.
>>>>>>>>>>   If you want to change the blacks, you have to rise the black
>>>>>>>>>>   value to see colors in the color picker, and at the end make
>>>>>>>>>>   it nearly black again. Would be much better to just chose a
>>>>>>>>>>   color and not having to worry about black.
>>>>>>>>>>   Also is it not very convenient not to have a live preview.
>>>>>>>>>
>>>>>>>>> All Kdenlive effects have live preview. So, a simple enhancement to
>>>>>>>>> toggle that would help.
>>>>>>>>
>>>>>>>> Well, there is live preview as soon as the color has changed in the
>>>>>>>> widget. But this is only the case when the color picker has been
>>>>>>>> closed already. There should be a built-in color picker.
>>>>>>>
>>>>>>> Yeah, like I suggested for white balance.
>>>>>>>
>>>>>>
>>>>>> I will take a look at this one. Maybe we could also reuse a color
>>>>>> selector from krita.
>>>>>
>>>>> Perhaps something like the HSV color wheel here
>>>>> http://en.wikipedia.org/wiki/Color_wheel would be good because even
>>>>> for high black values you still see the color.
>>>>>
>>>>> Perhaps a wheel that just ignores the black value (like a YUV wheel
>>>>> with fixed Y) would suit even better. Especially as the vectorscope
>>>>> uses YUV as well, this would make color corrections much easier. I'm
>>>>> currently trying (or, intending to try, should be learning actually)
>>>>> to produce a YUV circle for the vectorscope as background, but this
>>>>> could also be used for a color wheel later. When I get it, this
>>>>> shouldn't even be too difficult.
>>>>> Perhaps we'd still need to add the Y component separately.
>>>>>
>>>> What I thought of was Krita's Triangle Color Selector
>>>> (http://lukast.mediablog.sk/i/colorchoosers/krita-color-choosers.png).
>>>> However it is RGB based.
>>>
>>> I just realized that for White Balance, I was thinking about the
>>> eye-dropper. It would be nice to choose a color via eyedropper for
>>> White Balance and/or color-palette for other effects without the
>>> issues of a modal dialog.
>>
>> I think that is exactly what I tried to express :)
>
> Hi,
> in svn r4662 I now added a color picker ("eyedropper").

Cool! Thanks.

>> Please take a look at r4582. I've added a method
>> Vectorscope::yuvColorWheel which creates a YUV color wheel.
>> It is totally amazing what graphical effects you get when ignoring
>> char overflows.
>> I mean. The modified color wheel might suit quite well as color
>> picker. Perhaps it would require some more modifications to get more
>> differentiable saturation. (Actually the modified one was the original
>> YUV wheel which I identified as being just wrong. But it does seem
>> useful.)
>>
>> You can see the wheel in the vectorscope, when changing the background
>> (via combo box there). Works in an empty project as well.
>
> @Granjow: Do you want to implement a color chooser? If not I will adopt
> one from krita.
> Also take a look at this post:
> http://celarek.at/2010/07/krita-gsoc-colour-selectors-with-colourspaces-support/
> If they are finished we might want to adopt some to give the user
> several color choosers.

Atm I don't really have time. And the color choosers there look quite
good. Especially the bottom left one in the first picture. So I'd vote
for using one of them.

Simon