Turn PDF into grayscale

[gabrielle harrison and Paul van den Bergen]

On Tue, 27 Jun 2006 10:00:41 +1000, Dariusz J. Garbowski  
<thuforuk at yahoo.co.uk> wrote:
>>  So how is the gray scale value calculated?  is it just the average of  
>> the RGB values?
>>  e.g. would
>>      R   G   B
>>     126 0   0
>> and
>>     R   G   B
>>     0   126 0
>> and
>>     R   G   B
>>     0   0   126
>>  all convert to the same gray scale of
>>      R   G   B
>>     42  42  42
>>  ???
>
> It's not that simple.

and I'm glad I asked. :-)

thanks.

-- 
Dr Paul van den Bergen
Chance favours the prepared mind