[Tool] ChromIQ – a macOS and Windows GUI for ArgyllCMS printer profiling (v3.13.0-beta)

[riclin]

Hi Sebastian,

I've got a question regarding Step 4 - Build profile. In the manual settings one can set a A2B (-q) and a B2A (-b) quality. The info box states that B2A Quality is derived from A2B quality automatically, if B2A is not set. Reading the help for colprof says: Default for -b is Low quality. For me that means, one have to explicitly set the -b switch with a quality setting. A quick look at the sources for colprof confirmed that. Checking the ChromIQ log one can see that the call to colprof gets a -q argument but no -b. Are you really sure, that the info box text is correct?

Ronald
--

My understanding is that -b tracks -q unless specifically set otherwise. I also mentioned this in slightly more detail in response to the query in the YAAW thread.

 

[itsab1989]

Hi Sebastian,

I've got a question regarding Step 4 - Build profile. In the manual settings one can set a A2B (-q) and a B2A (-b) quality. The info box states that B2A Quality is derived from A2B quality automatically, if B2A is not set. Reading the help for colprof says: Default for -b is Low quality. For me that means, one have to explicitly set the -b switch with a quality setting. A quick look at the sources for colprof confirmed that. Checking the ChromIQ log one can see that the call to colprof gets a -q argument but no -b. Are you really sure, that the info box text is correct?

Ronald
--

I handed this over to Claude - hope this helps:

Hi Ronald,

thanks for the sharp question — and for actually reading the colprof sources before asking. You've hit a genuinely confusing spot in Argyll's documentation, and I'm happy to report the info box is correct. The subtlety is that there are two different "defaults" hiding in that -b flag:

Case 1 — you don't pass -b at all (this is what ChromIQ does when you leave B2A Quality unset). In colprof.c the B2A quality variable starts out as a sentinel:

int iquality = 1; /* A2B quality */
int oquality = -1; /* B2A quality same as A2B */

and later, after all the options are parsed, that sentinel is resolved like this:

if (oquality == -1) { /* B2A tables will be used */
oquality = iquality;
}

So with no -b on the command line, the B2A quality is copied from the A2B (-q) quality — exactly what the info box says.

Case 2 — you pass a bare -b with no letter after it. That's the one the usage text describes: "-b [lmhun] Low quality B2A table - or specific B2A quality…". In the source, the -b parser ends with:

} else
oquality = 0; /* bare -b, no argument → Low */

So "-b means low quality" is true — but only if you actually type -b. Omitting the flag entirely is a different code path. (Amusingly, there's a commented-out alternative usage line right below it in the source that says "…same as -q (def)" — Graeme knew.)

You can see it for yourself in two minutes, no source-diving needed. Build the same measurement twice and dump the table resolutions:

colprof -qh MyChart → iccdump: all six A2B/B2A tables at CLUT resolution 33 (high)
colprof -qh -b MyChart → iccdump: A2B tables at 33, B2A tables at 9 (low)

I ran exactly this on a real 1168-patch measurement to double-check before answering: without -b, the B2A tables come out at grid 33 — high quality, inherited from -qh. With a bare -b, they drop to grid 9.

So the ChromIQ log you looked at (a -q argument, no -b) is precisely the "inherit from A2B" case, and the info box describes it correctly. But your question shows the wording could make this trap clearer — the Argyll usage text really does read as if low were the default. I'll take that as a hint to mention the distinction in the info box.

Thanks again for checking so carefully — questions with source references are the best kind.

 

[mavtop]

@itsab1989 just a little question, if for you is easy, can you make the charts note printed at the same bottom level of the last row printed, i attach a screenshoot, or even more, at the printer minimal margin

i would like it will be printed starting from the Red Line or at the bottom printer margin if possible and when you have free time to spend on it

i will understand if you will not do it

 

[itsab1989]

@itsab1989 just a little question, if for you is easy, can you make the charts note printed at the same bottom level of the last row printed, i attach a screenshoot, or even more, at the printer minimal margin

i would like it will be printed starting from the Red Line or at the bottom printer margin if possible and when you have free time to spend on it

i will understand if you will not do it

Knut made me aware of your post and had a reply for you:

The notes box is by design only available on either side of the columns (strips) with labels. The main reason is that most supported instruments (such as i1Pro or ColorMunki/i1Studio) require to start and end on white space. Thus, placing the notes box on the bottom margin of where strip-reading ends is not supported. This equally applies to Portrait and Landscape orientation of the page. However, if you just desire the notes box to be on the long side, then change to portrait orientation. Then the notes box can be placed on the long side, left (default) or right.

Knut

 

[mavtop]

Sorry @itsab1989 maybe my phrases were not so easy to understand,

i mean on the same position, but printed starting lower than now

i try to explain with a screenshoot

i mean printed starting lower than the patch rows, see the red arrow, at the printer lower margin (or bottom margin) if possible, so no reading problems with patches but more space to print info/notes/etc.

 

[itsab1989]

Funny thing is that I told Knut that what you are saying was my interpretation of your request
Now I am not 100% sure to be honest but I think that at the moment it is centered. So if it gets longer it should grow in both directions. Or have you noticed text being cut off?

 

[mavtop]

Funny thing is that I told Knut that what you are saying was my interpretation of your request
Now I am not 100% sure to be honest but I think that at the moment it is centered. So if it gets longer it should grow in both directions. Or have you noticed text being cut off?

maybe you are right, it is centered, if so, it is perfect in this way, sorry to disturb you.

 

[mavtop]

Anyway i'm having a lot of problem to measure a chart,

on a m2 mac with an usb-c -> multiport (usb-A, hdmi, etc.) it can use the instrument, calibrate it and possibly read the patches, i see the light turn on and change while i'm reading the patches, but no line is never completed, at the end of line, after some seconds i left the button to stop the read, it says instrument lose connection and i can retry, save and quit, if i click on save a quit, it gave an error and i can;t retry to read patches again because of that error

I tried at different speeds also very very slow but always failed.

if i click retry (not pressing save and quit) i can read the strips again but still it tells me at the end there is a communication error.

So i tried on a x86 Mac with usb-A ports, but it fails to calibrate the device (while M2 succeds in this).

EDIT: i retried with the M2 mac and it now fails to calibrate the i1pro1, i suppose it broken in some way,
i have another one in my office (i bought to have another one) but all is postponed to next weekend.

it is very strange i used this device 4-5 times and it was perfect

Argggggggggg

 

[pharmacist]

Is the converter USB 2.0 to USB-C converter of good quality ?

 

[itsab1989]

Anyway i'm having a lot of problem to measure a chart,

on a m2 mac with an usb-c -> multiport (usb-A, hdmi, etc.) it can use the instrument, calibrate it and possibly read the patches, i see the light turn on and change while i'm reading the patches, but no line is never completed, at the end of line, after some seconds i left the button to stop the read, it says instrument lose connection and i can retry, save and quit, if i click on save a quit, it gave an error and i can;t retry to read patches again because of that error

I tried at different speeds also very very slow but always failed.

if i click retry (not pressing save and quit) i can read the strips again but still it tells me at the end there is a communication error.

So i tried on a x86 Mac with usb-A ports, but it fails to calibrate the device (while M2 succeds in this).

EDIT: i retried with the M2 mac and it now fails to calibrate the i1pro1, i suppose it broken in some way,
i have another one in my office (i bought to have another one) but all is postponed to next weekend.

it is very strange i used this device 4-5 times and it was perfect

Argggggggggg

May I ask what you are doing to have a reason to own 2 of those devices? I mean this out of pure interest because I can’t even really justify owning a ColorMunki for what I do (well now with the coding stuff I can).