[FFmpeg-user] Colorchart and colormap

Michael Koch astroelectronic at t-online.de
Mon Apr 25 22:49:13 EEST 2022


Am 25.04.2022 um 21:41 schrieb Paul B Mahol:
> On Mon, Apr 25, 2022 at 9:16 PM Michael Koch <astroelectronic at t-online.de>
> wrote:
>
>> Hi,
>>
>> I have some remarks and questions about the new "colorchart" source and
>> "colormap" filter.
>>
>> In "colorchart" is a small error in the yellow field. It should be 231,
>> 199, 31.
>> Source:
>> https://www.xritephoto.com/documents/literature/en/ColorData-1p_EN.pdf
>>
>> "colorchart" is missing in the table of contents of the documentation.
>>
>> Could you please also add an option for the chinese version which has
>> slightly different colors?
>> Source: https://www.aliexpress.com/item/32738129067.html
>> The RGB values are shown in the 5th picture. Code is below.
>>
>> In "colormap" I'd like to know how the color from the "source" image is
>> calculated. If a real image of a ColorChecker is used, then the borders
>> between the fields must somehow be excluded.
>>
> Center pixel of patch is picked, that is fastest way.
> There is separate software for processing real world colorcharts.
> (Dealing with geometric transformation and color averaging)

If colormap isn't for processing of real world colorcharts, then what 
else is its purpose?

Michael



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