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10 May 2011

i1 Profiler Update


I promised you an update after I had been using the new i1 Profiler in the field for a few weeks, so hear it is. I’ve done quite a few jobs with the new software now and I remain impressed with the quality of the profiles and have gotten used to, or worked around, or learnt to ignore some of the small interface niggles I have with the software.

I’ve used i1 Profiler to create profiles for two of my oldest and most regular customers - the artists Gilbert & George, and fashion and interiors company Photographic Interiors. Both are very demanding in different ways. Gilbert & George use two Epson printers to print their art and they use a mix of monochrome photography with bold graphic colours. Their works are often very large and so they need the two printers to match exactly so that panels can be printed across both. The nature of their work requires profiles that deliver very good neutrals and vivid colour saturation. The profiles I made with i1 Profiler for them matched their very high standards.

Photographic Interiors are demanding customers for a very different reason, they constantly are on the leading edge of digital production for the fashion and interior design market and use a very wide array of media. They produce garments and wall coverings for some of the very big names in UK fashion and design. In the past I have profiled printing onto real leather for them as well as many different fabric printing technologies. Due to the nature of the materials involved the gamuts are sometimes small and the processes sometimes inherently variable but they still need to achieve eye-popping colour. Again i1 Profiler was up to the task with the new profiling engine making the most of the fabric printing process I was profiling, even if I did have to wait an hour and a half for each set of patches to be washed and steamed before measuring them.

I’ve also done my first customer training on the software. I took a break from a family holiday to train the photographers of FotoLarko in Cyprus in creating profiles for their entire workflow. Explaining software to somebody else is always a good test of its ease of use and despite some slight difficulty with language (but obviously their English was much better than my Greek) we profiled their printers, cameras and monitors with the new software during the day and they haven’t come back with any questions yet.

There have been a few bugs found after the software was released, specifically problems reading dark colours with a i1 Pro, but X-Rite have produced fixes or work arounds and will probably issue a maintenance release soon. I’ve found I’m using the Saved Workflows feature a lot to store frequently used combinations of media size, instrument and black generation which makes things quicker. All the customers who have had profiles through our Custom Profile Service have been very happy with the results as well.

15 Apr 2011

i1 Profiler - Displays & Projectors






In this last blog looking at the new i1 Profiler software I’ll be covering monitor and projector profiling. The only instrument that is supported for display profiling is the i1 Pro, which is a shame since the i1 Pro spectrophotometer doesn’t measure low light values as well as a colorimeter, such as the i1 Display 2, although the i1 Pro can be more accurate at higher brightness values.

The Display Profiling workflow is pretty intuitive, even if you’ve never used a monitor profiling system before. The first option you get is to choose the White Point of your monitor, D65 (6500K) is the default. You can choose from a range of common values or measure your ambient lighting. The Luminance value defaults to 120 cd/m2. You also get to choose the Contrast Ratio, which is usually a factor of the luminance of the white point divided by the luminance level of the black point. If you are profiling multiple monitors then having the same contrast ratio can help to get a visual match. You’d have to profile each screen, see what contrast ratio each has and then set them all to the lowest value. The trouble with this approach is that most of the screens are no longer displaying at their full potential and are being dumbed down slightly.

The Profile Settings page allows you to set options such as Tonal Response Curve, Chromatic Adaptation and ICC Profile Version. Most customers won’t need to change from the defaults, apart from those using older versions of Photoshop who may find a version 2 ICC profile works better for them.

Once you click on the Measurement page you’ll see options to use Automatic Display Control (ADC) or Adjust brightness and contrast manually. Many monitors support ADC for automatic adjustment of the monitor. Both my MacBook Pro screen and my Lacie 324 have this feature, for example. Other monitors may not be able to be adjusted automatically and so you’ll have to interactively measure and adjust the brightness.

Interestingly you don’t get the option of adjusting the white point at all. i1 Profiler adjusts the video look up table of your graphics card to get the correct white point. This can be a good approach for cheaper monitors with poor controls but many monitors do have good adjustments for colour and it is disappointing not to be given the option of interactively changing and measuring the white point of the monitor. However, it did adjust the white point of my monitor using ADC but not precisely enough that it didn’t still have to make adjustments in the graphics card.

After the measurements have been done you can go on to the ICC Profile page and Create and save profile. You can then look at a graph of the gamut of your monitor and a graph of the adjustments made in the graphics card. You also get to see the range of Roman test images you get in the CMYK Printer Profiling workflow, and also have the option of loading your own. When you are viewing the test image you can click a before or after button to see the change in your monitor.

To further test your new monitor profile you can access the Display QA workflow. This takes the reference values from the classic 24 patch ColorChecker card, displays them on screen and then measures how close your monitor comes to displaying the colours accurately. Most previous monitor validation software I’ve used simply puts a series of colours through a profile, and then measures them to check the internal consistency and accuracy of the profile. The i1 Profiler approach of how well the monitor can display certain reference colours is different and I can see the benefit of it. What I would say though is that the little message you get at the bottom of the QA Report page, that the reference uses different measurements and some of the differences might be due to that, is not that reassuring. I’m assuming the reference values were done in D50 and since I profiled my screen at D65 that might be the difference X-Rite are referring to but a little more explanation or factoring in of the differences might make this feature more useful. I first profiled my display to 120 cd/m2 as usual and it failed the QA test but when I put it up to 140 cd/m2 it passed, just.


Now, I’ll be the first to admit that since I got the BasicColor Discus I have been slightly spoilt when it comes to monitor profiling. The profiles the Discus makes the best monitor profiles I’ve ever seen. That said i1 Profiler with an i1 Pro does a competent job that compares favourably with those from a ColorMunki, Spyder3 Elite or i1 Display 2. However, since i1 Profiler is X-Rite’s top of the range profiling product they could have put a few more features in to the Display Profiling workflow to reflect this. I think the lack of white point adjustment is a major omission and I also think an extended Display QA workflow that included uniformity checking would be good.

The Projector Profiling workflow is basically similar to the Display Profiling workflow, but you get no option to adjust the projector, the software simply profiles it as it is. You’ll need the Beamer attachment for your i1 Pro to profile a projector. The Projector QA workflow is also the same as Display QA. The projector profiles I got were slightly better than i1 Match.

My blog has covered all the major aspects of i1 Profiler now, but I’ll revisit it again in a few months after I’ve used the software on-site a bit more for customers. I used it yesterday for customer to profile their digital printing onto cloth and it did a very good job of profiling a difficult process and all the printer profiles I’ve made so far have been very good.

13 Apr 2011

CMYK Printer Profiling with i1 Profiler






In this blog I’ll be looking at CMYK printer profiling in the new i1 Profiler software, including the Printer Linearization, Printer QA and Data Analysis workflows. The new i1 Prism color engine in i1 Profiler seems to make exceptionally good CMYK profiles, although as with other parts of the software there are functions included that I think few people will use and some that don’t seem to have much effect, there are also a couple of features of ProfileMaker that I will miss.

Let’s start with the Printer Linearization workflow. Linearizing a printer ensures that each colour channel is printing in a defined linear fashion so that 50% of a colour is half as strong as 100%, for example. The software won’t let you linearize a RGB printer since most printers being profiled as RGB are only virtual RGB devices and are really printing with CMYK inks. Not all CMYK printers need linearizing in profiling software since most RIPs have a linearization function within the media calibration wizard and you’ll get better results linearizing there. If, however, you are profiling something like a simple colour laser without a RIP then you may get better results doing a linearization before you profile. You start by defining the number of patches per channel, 40 is more than enough, and then go on to set page size and print the chart. You then measure and save the linearization result. It would be nice to be able to see the curves at this point, as you could in Monaco Profiler.

When you start the CMYK Printer Profiling workflow you can then load your Linearization file and it will be applied to the colour patches you generate for the profiling and also embedded in the profile at the end of the process. Linearizing a printer profiling will get you a better profile because the colour patches will be more evenly distributed across the colour gamut of the printer.

When you generate patches for a CMYK profile you have additional options to the ones you had for an RGB profile. You can set the total ink coverage for the patches. If you’ve ink limited in your RIP then you can leave that to 400 but otherwise you can set it to lower amounts if the media you are profiling won’t take that much ink and you get drying or spreading problems. You can also set a slider for Patch weighting (dark/light), the theory behind this feature is that if you know you are going to be generating a profile with high level of black (more about this further down) then you can choose to have more dark patches. I haven’t had time to fully explore this option but I guess it might come into its own with some of the trickier types of media I profile such as cloth or leather.

The Test Chart, Measurement and Lighting pages are the same as for RGB profiling so I’ll skip over them and get to Profile Settings. It’s here that you set the black generation options. I haven’t got space to explain black generation in detail so I suggest if you are new to the concept that you go to the CMYK Printer chapter in Practical Colour Management, which you can download for free from our websites.

You can control the total ink coverage, how soon black ink or toner begins to be used in the tonal range and the maximum level of black. The Black curve control sets how much black is generated at any tonal level. Some devices suit quite a light black curve and with others you’ll get better results and save ink with heavier curves. You can view the K%/Lightness curve by clicking on the button on the control bar above the test image (more about that in minute). It would be good to be ale to view all the gradation curves as you can in Measure Tool. The black width control determines the range of colours affected by the black generation, a setting of zero means that only neutral colours are affected, 100 would mean all colours might be.

The Full black separation check box will produce very heavy black generation, and the Use intelligent black check box will stop the Black curve you’ve selected from compromising the total gamut of your profile, it is best to leave this on unless you have problems and need to force the behavior of the black curve.

The affect of any setting can be viewed by looking at the channels of the test images supplied, or indeed by loading your own. There are test images for high key, low key, mid tone and various colours so you can get a good idea how the profile will generate black before you do any test prints. Once you have made your black generation choices you can then go to the next page and create your profile. ProfileMaker had some pre-set black generation settings and I think it would be good for novice users if i1 Profiler adopted this approach as well, there is one fairly hidden offset printing preset you can use but there should be more. The Perceptual, Tables and Advanced options are the same as for RGB profiling.

Once you have built and tested your CMYK profile you can go to the Printer QA workflow to measure a control strip to see how well your device conforms to an international printing standard, or you can use this workflow to monitor the consistency of your printer over time. The software supports the popular IDEAlliance and FOGRA test wedges, which are fine for those familiar with proofing and press standards but it would have been nice if X-Rite had included the option of creating your own test wedge. Once you’ve measured your wedge you can compare it to an industry standard reference, or if you’ve previously saved the page data from a Printer QA measurement page you can use that as a reference to judge your own devices against each other or against themselves over time. At the end of the workflow you get a Pass/Fail result and details of the delta e values (colour differences) and you can save out a QA report. The Printer QA workflow could be useful for monitoring printer behaviour, although I think most users needing to use it would have the functionality built into their RIPs. The Data Analysis workflow allows you to get a similar report to the Printer QA workflow but allows you to compare any two sets of measurement data as long as they have the same number of patches. This could be useful for comparing results across different media on the same printer, the same media over time or the same media on two different printers.

I’ve been really impressed with the CMYK profiles I’ve made using the software so far, our first customer using the software was a a very demanding fine art printer and he is getting excellent results on a wide range of canvas and fine art media.

The next and final blog in this series will be on Display and Projector profiling.

6 Apr 2011

Profile Verification & Optimization







Two of the new features of i1 Profiler are the ColorChecker Proof profile verification option and Printer Profile Optimization. We’ll start with ColorChecker Proof. The software comes with a new version of the classic 24 patch Munsell ColorChecker but this one has a twist, it has holes in it.

The idea is that you click on the ColorChecker Proof workflow in the software and then drag and drop one of the profiles you’ve made onto the ColorChecker page icon. There is a check box to show which patches are out of gamut and so not expected to be matched on the printer. You then print the ColorChecker image and then get your ColorChecker Proof target and lay it over the print out. You’ll see the printed colours through the holes in the target and be able to evaluate the accuracy of the profile.

The main problems I have with this approach is that it obviously depends a lot on the light source you are viewing the print and the target under but also assessing areas of flat colour often tells you less about the accuracy of a profile than viewing a photographic image, with a wider range of tones and real world imagery we are familiar with such as faces, that our visual system has evolved to evaluate. So whilst I think the ColorChecker Proof is a useful tool I wouldn’t use it in isolation from conventional test images.

Once you have tested a profile you may choose to access the other new feature we’re talking about today, Profile Optimization. The Profile Optimization workflow takes an existing profile and analyses which areas might need a bit of improvement and generates a new set of patches to output and measure. Patches can be generated from images or spot colour libraries as well.

The technology is based on that in the ColorMunki software. The ColorMunki software only produces an initial 50 patch set so I can see the need for generating an additional second set. However, if you start by building an i1 Profiler profile with maybe 1000 or more patches there are unlikely to be many gaps that need filling. When I’ve tested Profile Optimization with RGB printer profiles I’ve never been able to see a visible difference in the final prints between and an optimized and un-optimized profile. There may well be small measurable differences in some colours but if the differences are not visible to the naked eye then it’s debatable if the procedure is worthwhile.

With CMYK printer profile you do sometimes get a small visual improvement and a larger measured improvement in Delta E values, but the improvement isn’t large in either case. I’ll need more time to assess this feature as I begin to use the software more in the field on a wider range of printers and technologies. However, I also find it curious that you can generate up to 6000 new patches and it will always generate the number you set. It never gives any feedback saying the profile is OK and can’t be improved or that only X number of patches are needed to make some improvement. It just generates the number of patches you ask it to. The level of improvement achieved is never quantified in any way either, so I’ve yet to be convinced but time will tell.

The other related feature to the ColorChecker Proof and Profile Optimization workflows is the Printer QA workflow, but we’ll tackle that next time when we talk about CMYK printer profiling.

5 Apr 2011

Using X-Rite i1 Profiler to calibrate your screen.

Here's another video demonstration of using the new X-Rite i1 Profiler software (i1 Basic Pro, i1 Photo Pro, & i1Publish Pro) to calibrate and profile your monitor.



For more information, please check out our website at www.nativedigital.com

4 Apr 2011

New videos about the X-Rite i1 Photo Pro

If you're keen to know more about the i1 Photo Pro, then these videos will give you a better understanding of the product and it's application.

The first video is just under 2 minutes and shows you the top 10 features of the i1 Photo Pro:




The last video is about US-based photographer Andy Katz - he show how he uses the i1 Photo Pro to help him throughout the photography process - from shooting RAW using the mini ColorChecker chart (to help with colour balance), profiling his monitors, profiling his printers and also profiling a digital projector - ensuring consistent and accurate colour every step of the way.



If you have any questions, please get in contact, or check out the i1 Photo Pro product page at www.nativedigital.com

29 Mar 2011

RGB Printer Profiling with i1 Profiler








Over the past few months I’ve been one of the team beta testing the new X-Rite i1 Profiler software, and now that it’s been officially released I can begin a series of blogs taking you through the new software. We’ll start with RGB printer profiling, in my tests the new software produces profiles that are noticeably better in many areas than i1 Match, ProfileMaker or Monaco Profiler. Also for users of i1 Match the new software includes advanced functionality previous only available in ProfileMaker or Profiler, but before we delve into the RGB printer profiling workflow it’s worth saying a few things about the general interface.

The opening screen or page of the software has several useful features including the ability to automatically check for software updates, access information about the software online and most important of all access training videos. One of my standard pieces of support advice is RTFM - Read The Flippin’ Manual. I’m sorry, but having written software manuals in the past I’m one of those people that reads the supplied manual for whatever they buy, it usually saves me a lot of time and lets me find features that might remain hidden if I didn’t know they were there. However, I realise not everybody gets on well with software manuals, apart from maybe as a cure for insomnia, so what I suggest is that the first time you open i1 Profiler you have a cup of coffee to hand and sit back and watch the training videos supplied via the handy button on the screen. They cover most of the functions of the software and are clear and very easy to understand.

i1 Profiler has two modes, Basic and Advanced. The Advanced mode really comes into its own when you’re profiling CMYK printers and for a lot of users doing just RGB printer profiling using the Basic mode will just stop you being presented with options that you’d always leave to default anyway, but in the interest of full disclosure I’ll write the rest of the blog assuming you are going to use the Advanced mode.

i1 Profiler uses a a step by step process and the options for each page can be saved into a workflow. Default workflows are supplied but you can also save your own to suit your own kit or processes. A workflow can include options such as the number of patches, page size and profile settings. Saved workflows, previous profiles and other saved data can be dragged and dropped onto the buttons in a workflow to set the options.

The first page, Patch Set, in an RGB printer profiling workflow defines the number of patches you want to measure. You can measure as few as 400 or up to 6000. In my experience you get little benefit from measuring over 1000 patches for an RGB printer profile. You have the option of scrambling or randomizing the order of the patches just in case there is any difference across the sheet, but there shouldn’t be on a inkjet printer. Once you have selected the number of patches you can then move on to the next page, Test Chart.

The Test Chart page allows you to define what measuring instrument you are using, the page size of your printer and other physical options relating to how the chart is laid out. You might have to step back and forth between Patch Set and Test Chart until you find a number of patches that fit on a certain number of pages. Personally, I think it would be better if they combined the Patch Set and Test Chart pages so you could define the page size and instrument then click a button to fill the page with patches. Anyway, once you have define the parameters you can then print the target or save it as a TIFF file.

The Measurement page is obviously where you connect your measuring device and measure the colours, and pretty much does what it says in a similar way to other profiling software. The next page, Lighting, is a new option that will be unfamiliar to users of i1 Match. Printer profiles can be built based on an expected viewing light to help improve the accuracy of the profile under that lighting condition. For example, if you were producing prints for a gallery that had a particular type of lights you could measure those lights and then use that measurement data when the profile was created to make the prints look good under that light source. Usually, however, you don’t know where the print will be viewed so the best thing for the vast majority of users is to leave the lighting options set to the default of D50 and skip the Lighting page.

Profile Settings also allows a lot of control over areas that most users will leave to default. The perceptual mapping options allow you to increase or decrease Contrast or Saturation and also the Neutralize gray option allows you to choose if gray colours are mapped relative to the colour of the paper or more absolutely neutral. The effect of these options will only be visible when printing with the perceptual rendering intent and I’d recommend first building a profile with the default options (all to zero) before changing anything. The effects are subtle but can be quite pleasing. The Tables option govern the size of the tables within the profile, again there isn’t much need to deviate from the defaults. By the way the defaults are displayed as ‘Custom’ for some reason - one of the issues I reported back during testing they didn’t have time to fix. Advanced sets other options most users won’t touch, you can find out what any option means by activating the Help function by clicking on the question mark at the bottom left of the screen and putting the cursor over the item you want explained.

The final ICC Profile page lets you save the profile. A 3D gamut graph of the profile is then displayed. You should then go and test the profile by outputting a few files before trying the new profile optimization and verification options, but more about those in the next blog.

If you want to test the quality of the profiles from the new software then we’ve already swapped our custom profiling service (http://www.nativedigital.com/products/Custom-ICC-Printer-Profile.html) over to using the new software.