Colormunki and chartread under Win 8.1 X64

[Roberto Revelli]

Hi,
my first post. I learned a lot reading this list .. therefore thank you
very much guys.

I upgraded 2 months ago my system from Win 7 X64 to Win 8.1 X64 .....
installed the colormunki driver with the well known procedure ...
everything is ok. (dispcalgui using binaries of argyll 1.6.2 works
flawless).

I have this strange problem: when i execute chartread.exe my colormunki
let me read just 4-5 columns and .. no more !! The button on the munki
seems broken. Chartread.exe (with the device blocked) reacts to the
commands of the keyboard (q,f,b).

My munki works perfectly if i use the colormunki photo 1.1.1 and i did
a lot of profiles in the past months under win 7 X64 with argyll without
any problem.

I tried to set the compatibility flag on the executable chartread.exe
... but no joy !!!!!

Any idea?

Tnx for your help and shame on me for my english :)

Roberto

[Graeme Gill]

I have this strange problem: when i execute chartread.exe my colormunki let me read just
4-5 columns and .. no more !! The button on the munki seems broken. Chartread.exe (with
the device blocked) reacts to the commands of the keyboard (q,f,b).

Hi,
I don't currently have a copy of Win 8.1, so it's hard to debug something like
this.

Try running it with the debugging turned on (-D7) and capture it to a log file
(chartread options etc... 2> log.txt), and mail _me_ the log.txt file.

Thanks,

Graeme Gill.

[BC Rider]

Hi,

When using the default value for the -r parameter I get (for example):

Peak err = 2.348581, avg err = 0.554618, RMS = 0.655012

And when changing the -r value to zero I get:

Peak err = 2.185529, avg err = 0.518934, RMS = 0.615882

Since -r=0 is a perfect, noiseless instrument, why don't the errors go to zero at those points? I had expected they would become "anchors" for the profiling algorithm given they are "perfect" but obviously not. I guess I need a conceptual sketch of what Colprof is actually doing to understand the behavior...any input appreciated!

How best to determine which -r value is "optimum" for a given profile?

Thanks.

PS. I also tried -r=2 and got: Peak err = 7.55, avg err = 1.222, RMS =1.46. Does that result tell me anything useful? And, for fun, I tried -qu option (just to prove it doesn't work!) and the error was basically identical to the -r=0 results. Does that tell me anything useful?

[Graeme Gill]

Post by BC Rider
Hi,
Peak err = 2.348581, avg err = 0.554618, RMS = 0.655012
Peak err = 2.185529, avg err = 0.518934, RMS = 0.615882
Since -r=0 is a perfect, noiseless instrument, why don't the errors go to zero at those points?

Hi,
the -r parameter is translated through a table into the actual underlying
smoothing values based on various scaling factors and experience, and the interpolation
algorithm won't work with no smoothing, since it would then have no means of doing
interpolation. In addition, if you have two points within the same locality as a grid
node that are inconsistent with the grid interpolation (ie. think two different
measurements for the same device values), then of course the profile can't satisfy both
at the same time, hence a minimum fit error.

You can set the raw underlying smoothing factor using "-r rX.XXXeX", but be warned
that off hand I'm not sure what value you would start with (it could be as
small as 1e-8, or as large as 1.0, I can't recall), and will vary with dimensionality
and number of test points.

Graeme Gill.

[Gerhard Fürnkranz]

Isn't there also a -rs option for suplying a relative scaling for the default raw factor? 0.3, 0.1, 0.03, 0.01,... (i.e. geometric scale with 2 steps per decade) are IMO good candidates to try for less smooth profiles than default. The defaults seem to be indeed rather smooth, but an "optimal" value which e.g. minimizes cross validation errors does not always give pleasing results on the other hand (so it may be safer to renounce 1 or 2 dE for better smoothness).
--
Best Regards,
Gerhard

Post by BC Rider

Post by BC Rider
Hi,
When using the default value for the -r parameter I get (for
Peak err = 2.348581, avg err = 0.554618, RMS = 0.655012
Peak err = 2.185529, avg err = 0.518934, RMS = 0.615882
Since -r=0 is a perfect, noiseless instrument, why don't the errors

go to zero at those points?
Hi,
the -r parameter is translated through a table into the actual
underlying
smoothing values based on various scaling factors and experience, and the interpolation
algorithm won't work with no smoothing, since it would then have no means of doing
interpolation. In addition, if you have two points within the same locality as a grid
node that are inconsistent with the grid interpolation (ie. think two different
measurements for the same device values), then of course the profile can't satisfy both
at the same time, hence a minimum fit error.
You can set the raw underlying smoothing factor using "-r rX.XXXeX", but be warned
that off hand I'm not sure what value you would start with (it could be as
small as 1e-8, or as large as 1.0, I can't recall), and will vary with dimensionality
and number of test points.
Graeme Gill.

[Gerhard Fürnkranz]

Isn't there also a -rs option for suplying a relative scaling for the default raw factor? 0.3, 0.1, 0.03, 0.01,... (i.e. geometric scale with 2 steps per decade) are IMO good candidates to try for less smooth profiles than default. The defaults seem to be indeed rather smooth, but an "optimal" value which e.g. minimizes cross validation errors does not always give pleasing results on the other hand (so it may be safer to renounce 1 or 2 dE for better smoothness).
--
Best Regards,
Gerhard

Post by BC Rider

Post by BC Rider
Hi,
When using the default value for the -r parameter I get (for
Peak err = 2.348581, avg err = 0.554618, RMS = 0.655012
Peak err = 2.185529, avg err = 0.518934, RMS = 0.615882
Since -r=0 is a perfect, noiseless instrument, why don't the errors

go to zero at those points?
Hi,
the -r parameter is translated through a table into the actual
underlying
smoothing values based on various scaling factors and experience, and the interpolation
algorithm won't work with no smoothing, since it would then have no means of doing
interpolation. In addition, if you have two points within the same locality as a grid
node that are inconsistent with the grid interpolation (ie. think two different
measurements for the same device values), then of course the profile can't satisfy both
at the same time, hence a minimum fit error.
You can set the raw underlying smoothing factor using "-r rX.XXXeX", but be warned
that off hand I'm not sure what value you would start with (it could be as
small as 1e-8, or as large as 1.0, I can't recall), and will vary with dimensionality
and number of test points.
Graeme Gill.

[Graeme Gill]

Post by Gerhard Fürnkranz
Isn't there also a -rs option for suplying a relative scaling for the default raw
factor? 0.3, 0.1, 0.03, 0.01,... (i.e. geometric scale with 2 steps per decade) are IMO
good candidates to try for less smooth profiles than default.

Hello Gerhard,
yes indeed, this may be a better way to play with tweaking it.
Graeme.

[Roberto Revelli]

Solved !!!

Sorry for my post: nothing to do with bug in chartread.... the culprit
was the usb hub where i connected the Munki.... changed hub and now
everything works like expected.

Tnx Gill for your reply,

roby

[Graeme Gill]

Sorry for my post: nothing to do with bug in chartread.... the culprit was the usb hub
where i connected the Munki.... changed hub and now everything works like expected.

Good to know that it's not a mystery.

Graeme Gill.