Working space and Colorvision Profiler Pro

Greg wrote:

Hi,
I’m using Profiler Pro V2.3 to profile my Epson 2200.

In the documentation, it says that during profile creation, the working space in Photoshop should be the same
as the working space that will be used afterwards, while editing and printing images. It also says that it is important
to always use this same working space, because otherwise there will be a colour shift. This makes sense – I have read
elsewhere that profiles are (or can be) to an extent optimised for a particular source gamut.

This is all fine, except that what I’m noticing is that the resulting profile seems to behave identically, *regardless* of
the working space I use while building the profile! Has anyone else noticed this? Should I tag all the Profiler Pro
ancilliary images (the images it opens up during the profiling, and which are tagged by default with Adobe RGB)
with my new working space? Should I *convert* them all to my working space?

I am in touch with Colorvision support as well, but so far they don’t even seem to understand what my issue is.

Photoshop is designed to recognize embedded profiles, and honor them for printing and display purposes. The end goal of this is consistency, which is what you are seeing.

There are ways to thwart this – for example by selecting the "Same as source" option in the print dialog, and this may well be what the Colorvision folks are refering to. For more detail, see:

< http://www.computer-darkroom.com/ps7_print/ps7_print_mac_2.h tm>

—

Mike Russell
www.curvemeister.com
www.geigy.2y.net

"Mike Russell" wrote in message

Photoshop is designed to recognize embedded profiles, and honor them for printing and display purposes. The end goal of this is consistency, which is what you are seeing.

I understand this. When I said "identical results", I mean *exactly* – the resulting pixel values are 100% identical.
This doesn’t make sense to me at all. If Colorvision really mean what they say, then when I build two different
profiles (using two different working spaces during the profile creation), I would expect at least the perceptual
tables to produce slightly different colours, when I switch between the two profiles. It appears to me that
it makes no difference whatsoever what my working space is set to during profile creation – this is contrary
to the Profiler Pro documentation.

Greg.

Greg wrote:

"Mike Russell" wrote in message

Photoshop is designed to recognize embedded profiles, and honor them for printing and display purposes. The end goal of this is consistency, which is what you are seeing.

I understand this. When I said "identical results", I mean *exactly* – the resulting pixel values are 100% identical. This doesn’t make sense to me at all. If Colorvision really mean what they say, then when I build two different profiles (using two different working spaces during the profile creation), I would expect at least the perceptual tables to produce slightly different colours, when I switch between the two profiles. It appears to me that it makes no difference whatsoever what my working space is set to during profile creation – this is contrary to the Profiler Pro documentation.

Perhaps the documentation is not correct in this respect. This is the way I see it: First you print a color chart. It shouldn’t really matter in which color space you opened that chart, because in the end you will print it in the *printer color space*. That’s all the printer can do. Next you measure the results by scanning that print. You build the profile based on that, so I don’t see any reason why the profile should be different if the color space of the chart is different. As long as you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/

"Johan W. Elzenga" wrote in message

Perhaps the documentation is not correct in this respect.

I’ve been kind of wondering whether this might be the case.

This is the
way I see it: First you print a color chart. It shouldn’t really matter in which color space you opened that chart, because in the end you will print it in the *printer color space*.

Agreed/understood.

That’s all the printer can do.
Next you measure the results by scanning that print. You build the profile based on that, so I don’t see any reason why the profile should be different if the color space of the chart is different. As long as you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used.

I have read that it is possible to optimise the perceptual intent tables for different assumed
*source* gamuts. For example, if the source gamut is large (e.g, Ekta Space), the perceptual conversion
needs to scale the gamut down much more than if the source gamut is small (e.g, sRGB). This is what I thought Profiler Pro might be trying to do – optimise the perceptual tables for the user’s working space. So, by some means, I thought the Profiler Pro
plugin might have determined what the current working space is (during profile creation), and taken that into account while
actually building the profile. The documentation is very clear in it’s directive to set the working space during profile creation to whatever working space will be used afterwards. But as you say, it may just be incorrect.

Greg.

"Johan W. Elzenga" wrote in message
As long as

you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used.

Also, note that other images (two, I think) are opened by Profiler Pro, *during* the profile creation. I don’t
think these images are important – I think Profiler Pro just needs *any* image open for certain
operations, simply because it’s a Photoshop plugin. These images are tagged with Adobe RGB,
and the documentation clearly says not to convert them when opening. (i.e, to leave them in Adobe RGB).

Greg.

Greg wrote:

"Johan W. Elzenga" wrote in message
As long as

you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used.

Also, note that other images (two, I think) are opened by Profiler Pro, *during* the profile creation. I don’t think these images are important – I think Profiler Pro just needs *any* image open for certain operations, simply because it’s a Photoshop plugin. These images are tagged with Adobe RGB, and the documentation clearly says not to convert them when opening. (i.e, to leave them in Adobe RGB).

I can understand that you shouldn’t *convert* anything. That makes sense. Let say that the color chart contains a patch with RGB values 200,200,200. You print this on your printer and next you scan this print. The scan will be opened in your default color space, so that will be AdobeRGB. Because the original chart was in AdobeRGB as well, the software can make a direct comparision: The scanned patch should be 200,200,200 again, but it won’t be. The difference is what is used to make the profile. However, if you opened the chart and used "Convert to profile" in order to use another color space, the original patch value would not be 200,200,200 any longer. It will be converted to something else, so you printed something else. Scan this into AdobeRGB, and you obviously find a value that is not 200,200,200. Not because of the printer, but because the value wasn’t 200,200,200 to begin with. The result is that your new profile will be off.

By the way, it seems that Profiler Pro works a little differently from the one I got. I have PrintFIX and DoctorPRO. PrintFIX doesn’t open any other image during profile creation. DoctorPRO does open an image during profile correction, but that seems indeed because something has to be open (DoctorPRO runs an action, that can’t run if there’s no open document).

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/

"Johan W. Elzenga" wrote in message

By the way, it seems that Profiler Pro works a little differently from the one I got. I have PrintFIX and DoctorPRO. PrintFIX doesn’t open any other image during profile creation.

FWIW, I’ve just tried it again, and it opens an image called "Colorvision.tif" twice –
once when I open the measurements file, and once when I click the ok button to
generate the profile. The image is the colorvision logo.

DoctorPRO does open an image during
profile correction, but that seems indeed because something has to be open (DoctorPRO runs an action, that can’t run if there’s no open document).

Indeed.

Greg.

Greg wrote:

"Johan W. Elzenga" wrote in message

By the way, it seems that Profiler Pro works a little differently from the one I got. I have PrintFIX and DoctorPRO. PrintFIX doesn’t open any other image during profile creation.

FWIW, I’ve just tried it again, and it opens an image called "Colorvision.tif" twice – once when I open the measurements file, and once when I click the ok button to generate the profile. The image is the colorvision logo.

Could well be that this is for entertainment only. Personally, I can’t see why the Colorvision logo would be needed to create a profile!

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/

On Sat, 17 Jan 2004 14:31:25 +0100, (Johan W.
Elzenga) wrote:

Greg wrote:

"Johan W. Elzenga" wrote in message
As long as

you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used.

Also, note that other images (two, I think) are opened by Profiler Pro, *during* the profile creation. I don’t think these images are important – I think Profiler Pro just needs *any* image open for certain operations, simply because it’s a Photoshop plugin. These images are tagged with Adobe RGB, and the documentation clearly says not to convert them when opening. (i.e, to leave them in Adobe RGB).

I can understand that you shouldn’t *convert* anything. That makes sense. Let say that the color chart contains a patch with RGB values 200,200,200. You print this on your printer and next you scan this print. The scan will be opened in your default color space, so that will be AdobeRGB. Because the original chart was in AdobeRGB as well, the software can make a direct comparision: The scanned patch should be 200,200,200 again, but it won’t be. The difference is what is used to make the profile. However, if you opened the chart and used "Convert to profile" in order to use another color space, the original patch value would not be 200,200,200 any longer. It will be converted to something else, so you printed something else. Scan this into AdobeRGB, and you obviously find a value that is not 200,200,200. Not because of the printer, but because the value wasn’t 200,200,200 to begin with. The result is that your new profile will be off.

By the way, it seems that Profiler Pro works a little differently from the one I got. I have PrintFIX and DoctorPRO. PrintFIX doesn’t open any other image during profile creation. DoctorPRO does open an image during profile correction, but that seems indeed because something has to be open (DoctorPRO runs an action, that can’t run if there’s no open document).

But if your printer normally expects an sRGB (converted or otherwise from Adobe RGB), doesn’t it make sense to convert to sRGB anyhing sent to the printer first? Of course you could set PS to work in sRGB, but that seems counterproductive. Or maybe with Profiler, you just forget all that sRGB business and use the profile that it creates?

Do you have a color reflection densitometer? Maybe this could be used to verify that your Profiler program is doing what it’s supposed to. Get a known color reference chart and compare it to the printed results from a scanned-in copy. Also there’s no guarantee that your scanner has perfect color, either–maybe this why Profiler has those color tweaks available.

"Pard" wrote in message

But if your printer normally expects an sRGB (converted or otherwise from Adobe RGB), doesn’t it make sense to convert to sRGB anyhing sent to the printer first? Of course you could set PS to work in sRGB, but that seems counterproductive. Or maybe with Profiler, you just forget all that sRGB business and use the profile that it creates?
Do you have a color reflection densitometer? Maybe this could be used to verify that your Profiler program is doing what it’s supposed to. Get a known color reference chart and compare it to the printed results from a scanned-in copy. Also there’s no guarantee that your scanner has perfect color, either–maybe this why Profiler has those color tweaks available.

I am using the raw mode of my Epson 2200, and it most certainly does not expect
sRGB! The profiler is indeed working well – colours are accurate, greyscale is neutral, and
I can print colours way outside sRGB. (e.g, Lab 41,-33,-36, confirmed by measuring with a
colorimeter)

Greg.

Pard wrote:

But if your printer normally expects an sRGB (converted or otherwise from Adobe RGB), doesn’t it make sense to convert to sRGB anyhing sent to the printer first? Of course you could set PS to work in sRGB, but that seems counterproductive. Or maybe with Profiler, you just forget all that sRGB business and use the profile that it creates?

Of course you should forget about sRGB and use the printer profile you just created. What is the use of making a printer profile if you don’t use it?

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/

"Johan W. Elzenga" wrote in message

Could well be that this is for entertainment only. Personally, I can’t see why the Colorvision logo would be needed to create a profile!

No, I do not think it’s for entertainment. I think it’s simply that it needs *any* image open,
just like Doctor Pro. However, it is possible that the colour space of this image matters.

I’ve just dumped the perceptual tables (B2A0 tags) from the two different profiles (one made with Adobe RGB set as my working
space, the other made with Ekta Space set as my working space), and they are identical – the working space I used
made absolutely no difference to the resulting printer profile. Anyway, I’m now talking to someone at Colorvision who seems much more technical than the first person – I’ll report back after we’re done.

Greg.

Just to bring a bit of closure to my original question – Colorvision say that the working space *does* make
a difference, when using CMYK profiles. They haven’t actually yet agreed that there is no difference whatsoever
for RGB profiles, but they seem to agree that the documentation should ideally be changed, to move the advice to use
whatever working space *during* the profiling, that is intended to be used aftewards for actual
printing, to the CMYK profiling section of the document.

I can’t use CMYK profiles so I’m not going to bother trying to verify this.

Greg.