Digital BW, The Print

----- Original


AFAIK the Excel 'spectral calculator spreadsheets' on this page
http://www.brucelindbloom.com/SpectCalcSpreadsheets.html

will do what you want.

Regards,

Alan

--------

Alan
I had a look at these, and they are not what I want. I need something 
simpler, that will simply convert  a Lab value into an RGB one, in the same 
way as this color converter does:
http://www.colorpro.com/info/tools/convert.htm#TOP

except I would like the calculations to be done in a spreadsheet, so I can 
covert a full set of  readings at a time.

Brian

I think there's no such thing in the sense that RGB is not a colour model
per se.  You would have to define which RGB space.  The numbers for R, G and
B, respectively, for a given CIELab colour will be different for each RGB
space (Adobe RGB, ProPhoto RGB etc) and in fact there may not be an RGB
number for many CIELab colours - because of gamut limitations.

> From: Brian <brian@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Fri, 24 Mar 2006 13:50:08 -0000
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: Re: [Digital BW] Re: LAB to RGB formula?
> 
> 
> ----- Original
> 
> 
> AFAIK the Excel 'spectral calculator spreadsheets' on this page
> http://www.brucelindbloom.com/SpectCalcSpreadsheets.html
> 
> will do what you want.
> 
> Regards,
> 
> Alan
> 
> --------
> 
> Alan
> I had a look at these, and they are not what I want. I need something
> simpler, that will simply convert  a Lab value into an RGB one, in the same
> way as this color converter does:
> http://www.colorpro.com/info/tools/convert.htm#TOP
> 
> except I would like the calculations to be done in a spreadsheet, so I can
> covert a full set of  readings at a time.
> 
> Brian

I agree with Steve. When going from CIELab to RGB values you need to
define the colour space. If you want to choose a color space I could
adapt one of my existing Excel spreadsheets. If you tell us more about
exactly what you wish to do, we may be able to help more.

Best,
Helen 

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale
<stevekale@...> wrote:
>
> I think there's no such thing in the sense that RGB is not a colour
model
> per se.  You would have to define which RGB space.  The numbers for
R, G and
> B, respectively, for a given CIELab colour will be different for
each RGB
> space (Adobe RGB, ProPhoto RGB etc) and in fact there may not be an RGB
> number for many CIELab colours - because of gamut limitations.
> 
> 
> > From: Brian <brian@...>
> > Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> > Date: Fri, 24 Mar 2006 13:50:08 -0000
> > To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> > Subject: Re: [Digital BW] Re: LAB to RGB formula?
> > 
> > 
> > ----- Original
> > 
> > 
> > AFAIK the Excel 'spectral calculator spreadsheets' on this page
> > http://www.brucelindbloom.com/SpectCalcSpreadsheets.html
> > 
> > will do what you want.
> > 
> > Regards,
> > 
> > Alan
> > 
> > --------
> > 
> > Alan
> > I had a look at these, and they are not what I want. I need something
> > simpler, that will simply convert  a Lab value into an RGB one, in
the same
> > way as this color converter does:
> > http://www.colorpro.com/info/tools/convert.htm#TOP
> > 
> > except I would like the calculations to be done in a spreadsheet,
so I can

> > covert a full set of  readings at a time.
> > 
> > Brian
>