Re: [gentoo-user] CMYK comparison to sRGB between platforms

[Peter Humphrey]

On Sunday 27 September 2015 10:47:51 Mick wrote:
> On Sunday 27 Sep 2015 09:58:43 Peter Humphrey wrote:
> > I do have the two .icc files in .local/share/icc:
> >
> > $ ls -l .local/share/icc
> > total 28K
> > -rw-r--r-- 1 prh prh 1.2K Sep  9 16:51
> > edid-fbec4f9c1804ea718b6e1b585fc234ad.icc -rw-rw-r-- 1 prh prh  21K Sep 10
> > 10:41 GCM - Samsung - SMS27A350H - unknown (2015-09-10) [04-58-44].icc
> >
> > /usr/bin/file shows them both as "ColorSync ICC Profile". I don't know why
> > there are two, nor why they have such different sizes.
>
> I'm guessing that the 'edid-fbec4f9c1804ea718b6e1b585fc234ad.icc' was
> extracted from your monitor's EEPROM chip through the i2c bus and saved on
> disk by the LiveCD you ran, but the 'GCM - Samsung - SMS27A350H - unknown
> (2015-09-10) [04-58-44].icc' was generated by the colorimeter during your
> calibration exercise.
>
> I'm also guessing that the smaller size of the first file is because your
> monitor's EDID is of an earlier version, e.g. EDID-v1.1 or some such, which
> used to only contain a 128-byte data structure.  I seem to recall that very
> early EDID versions didn't even contain colospace and Gamma data, but may be
> wrong.

I've just visited the Taxi site you mentioned to see what's there for my 
monitor. Nothing! So I tried uploading my ColorHug data. The page asked for a 
metadata file and a profile data file, from which I supposed that my smaller file 
is metadata about the content of the larger one. But when I tried to upload 
the two files on that assumption I got a server error. Same when I tried them 
the other way round.

Looking at the larger file with less, I find eight lines of binary data at the 
head followed by 400-odd lines of legible textual data. Interesting stuff, 
though of course I don't know what to do with it myself.

> These are [Mick's] sizes :
>
> ls -n ~/.local/share/color/icc/devices/Display/
> total 800
> -rw-r--r-- 1 1001 1001   1944 Sep 18 18:16 ACI ASUS VS239
> EALMTF200702_edid.icc
> -rw-r--r-- 1 1001 1001   2016 Sep 18 18:16 Dell Computer DELL ST2320L
> MP82K0712EJL_edid.icc
> -rw-r--r-- 1 1001 1001  20884 Sep 18 19:01 P2311H 2012-06-20 2.2 MQ-HQ
> 3xCurve+MTX.icc
> -rw-r--r-- 1 1001 1001 783804 Sep 18 19:02 PA248 2015-04-18 S
XYZLUT+MTX.icc
>
> The first two are from the monitors' EDID content, the latter are the
> profiles I downloaded from the Taxi DB.  Some of these contributors'
> profiles were created with spyder or other expensive colorimeters, so I am
> surmising that they capture more data points and contain more information,
> than the manufacturers EDID which is primarily contains other than
> colorspace and Gamma data.

Lucky you! As I said, my monitor hasn't made it into the database yet. And it 
seems I can't contribute to it either.

-- 
Rgds
Peter