Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Digital Photography > why device independent color?

Reply
Thread Tools

why device independent color?

 
 
Martin Brown
Guest
Posts: n/a
 
      01-27-2014
On 27/01/2014 17:53, isw wrote:
> In article <UcpFu.5703$(E-Mail Removed)4>,
> Martin Brown <|||newspam|||@nezumi.demon.co.uk> wrote:
>
>> On 24/01/2014 23:47, Eric Stevens wrote:
>>> On Fri, 24 Jan 2014 12:13:47 -0500, nospam <(E-Mail Removed)>
>>> wrote:
>>>
>>>> In article <(E-Mail Removed)>, Dale
>>>> <(E-Mail Removed)> wrote:
>>>>
>>>>>>
>>>>>> what is needed is a colour managed workflow, with the image and each
>>>>>> device along the way having a profile.
>>>>>>
>>>>> that's how you get the profiles
>>>>
>>>> no, you get the profiles by running the appropriate profiling software.
>>>>
>>>> what the software does internally doesn't matter. users do not need to
>>>> understand all the math behind it to be able to use it.
>>>>
>>>> what matters is does the user get what they expect, and the answer is
>>>> yes.
>>>
>>> You are missing the point of Dale's original comment:
>>>
>>> "you need to convert the device colors through device independent
>>> color space like XYZ,CIELAB,CIELUV".

>>
>> But that is clearly not true!
>>
>> It is a lot more convenient to convert to a device independent colour
>> space and from there to whatever output medium you want to use because
>> the number of profiles need for N different image sources and M
>> destinations is limited to N+M colour profiles.
>>
>> But you could with a *lot* more work compute direct colour profiles for
>> every possible combination of source and destination N*M. In the early
>> days when N was about 3 and M was about 4 that was what happened.
>>
>> It may still make a lot more sense to store the original image in the
>> colour space where it was measured and only ever compute the device
>> independent form as a hidden step on the way to the output device.

>
> What do you do years later, when all information about the creating
> device's characteristics are long gone, and all you have is an image
> file?


In the digital age you struggle badly unless you can recognise the data
format. There are plenty of data "archives" now virtually inaccessible.
An example of a UK one that required heroic efforts to resurrect was the
BBC Domesday Project with multimedia from only 1986.

http://www.atsf.co.uk/dottext/domesday.html

Finding a still surviving videodisc player was only half the problem.

--
Regards,
Martin Brown
 
Reply With Quote
 
 
 
 
Martin Brown
Guest
Posts: n/a
 
      01-28-2014
On 27/01/2014 22:48, Eric Stevens wrote:
> On Mon, 27 Jan 2014 10:29:50 -0800, isw <(E-Mail Removed)> wrote:
>


>> And just to keep things sort-of on topic, despite its limitations,
>> NTSC's color space was larger than that of any other commercial color
>> reproduction technique that existed at the time. (And that includes
>> color photographic film).
>>

> Wow!
>
> That brings us back to Dale's original topic. You couldn't say "NTSC's
> color space was larger than that of any other commercial color
> reproduction technique that existed at the time" unless you had a
> device independent space (such as "XYZ, CIELAB, CIELUV) through which
> you can connect them.
>
> Many thanks.


Yes you could by showing that the other colour spaces gamut could be
represented as a subset of the NTSC colour space. I am not convinced the
claim is true about NTSC though it was for a while a de facto colour
space standard in practice.

The fact is though that CIE 1931 predates all of the modern device
independent colour spaces in trying to encode human colour perception.

http://en.wikipedia.org/wiki/CIE_1931_color_space

And it was obviously available when NTSC 1953 was defined. The RGB
phosphors were in fact specified by their position on CIE 1931.

--
Regards,
Martin Brown
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Why is there no platform independent way of clearing a terminal? Daniel Fetchinson Python 49 08-06-2010 02:42 AM
Changing font color from current font color to black color Kamaljeet Saini Ruby 0 02-13-2009 04:58 PM
why why why why why Mr. SweatyFinger ASP .Net 4 12-21-2006 01:15 PM
findcontrol("PlaceHolderPrice") why why why why why why why why why why why Mr. SweatyFinger ASP .Net 2 12-02-2006 03:46 PM
C++ object for Device Independent Bitmaps David Cox C++ 5 08-01-2005 02:12 AM



Advertisments