Help with displaying website images

[Stephen Willard]

I have calibrated my mac for a gamma of 2.0 and imbedded the color profile sRGB IEC61966-2.1 in all my images. Typically, my images range from deep shadows to extreme highlights and are very sensitive to gammas that differ from my calibration.

I have recently made a effort to view my website on other peoples machines (non-technical people with uncalibrated computers) and was horrified how varied the images were from very dark to very light. PCs were typically too dark while macs were too light.

Is there any solution to this problem? I suspect the villain is the varied gamma setting of the computers. Can gamma be controlled by color profiles? My impressions are color profiles only manage colors, but not gamma settings.
Is this true?

I also believe the Microsoft browser does not use color profiles embedded in the images and simply defaults to sRGB IEC61966-2.1.
Is this true?

Are there any solutions to this problem? I am actually thinking about presenting the viewer with three identical images: one corrected for a gamma of 2.5, one at 2.0, and at 1.4. The viewer would select the image he feels looks best just prior to accessing my online gallery. I would then display a suite of images that have been corrected for the corresponding gamma. Unfortunately, this would require me to generate three suites of images for each photograph corresponding to gamma 2.5, 2.0, and 1.4.


FACTS:
1. In general, photographers do not buy fine-art photographs. They buy equipment. These are the people who calibrate their machines.

2. 85% of my sales are from women. From my surveys and emails with these patrons, they do not use calibrated computer systems.

3. The vast majority of computers do not employ color management solutions.

Any help would greatly be appreciated. Thanks.

[stompyq]

I've seen some websites that employ a stepwise b&w gradiant to adjust gamma. The site simply requests that you adjust moniter brightness and contrast so that you'll see seperation in the lightest and darkest tones. This should work at least partially. I've been thinking about this solution since one of my co-workers commented about how crappy my site looks on the lab moniter. All it needed was a little tweaking of the brightness and things looked normal.

[Bruce Watson]

Is there any solution to this problem?

No, there's not. The reason is inherent in the web itself. The web was designed to separate content, which you control, from display, which the end user controls.

About the best you can do is also provide some guides in the form of instructions and a gradient or step wedge. If you can talk the viewer into tweaking their monitor to "properly" display your step wedge you've done about all you can do.

[Stephen Willard]

I have a step wedge, but I believe that most non-technical people will not know how nor bother to adjust their gamma even if they new how. That is why I am leaning toward the picture approach which puts the burden on me to triplicate every image thumbnail and enlargement. The viewer simply selects what looks best to her, and then I can display the images that will provide a close approximation of how she likes it. I believe this gamma problem is costing me sales, and it would be worth it to me to triplicate my images. No fun!

Does anyone have a feel for the gammas of 2.5, 2.0 and 1.4 I picked?

[Jack Flesher]

I think your first problem is that sRGB is a 2.2 gamma space. Working in 2.0 would open shadows and supress highlights relative to 2.2, and this would not get accurately translated to sRGB. I suspect if you balance your images under a monitor gamma of 2.2 you be far happier with your web results.

Cheers,

[Marko]

Hi Stephen,

First let me state some facts:

1. The only current major browser that is color-management aware is Safari on the Mac. It will correctly use whichever profile it finds embedded into an image and will use monitor profile for untagged ones.

2. All other browsers simply use sRGB color space, which is, arguably, the target space of the www.

3. Virtually all monitors on the market today, save for very few very expensive models, are capable of displaying only sRGB gamut.

4. The Gamma is set by the color profile. Since most browsers are not color managed, they simply ignore the embedded profile and use the monitor profile. Since so do most Windows users too, their systems revert to their default settings - gamma 2.2 and sRGB.

So, the best way to approach the problem is to do the following:

1. Set your working gamma to 2.2. Since you're on the Mac, the easiest way to do this is to create a specialized profile which you can switch on or off as you please. You can also make it sRGB when at it, but this is not really neccessary.

2. Process your images as usual and then convert them to sRGB profile as the very last step before saving for Web (be careful to save the originals before this step!).

3. Once converted, save the images using Save for Web option. This option allows you to customize the compression of your images while previewing the impact on image quality. Crucial for web optimization, since it lets you pick the best compromise. This option also strips all the "extras" that most browsers ignore anyway, such as preview icon and color profile.

The product is an image with no color profile embedded, but with the gamut properly reduced to fit the viewing capabilities.

What happens if you do not convert your image from, say, Adobe RGB or any other wide-gamut color space, prior to posting the image on the web is that your gamut will get clipped to fit the active monitor profile instead of being translated. The only exception being Safari for Mac, but if you use Save for Web, which you should, there will be no color profile for it to read, so it will use the current monitor profile and hence clip the image anyway.

Converting the image to sRGB prior to Saving for Web will correctly compress all your colors into the sRGB color space and the image will appear more natural and more vibrant.

4. As for gamma, it varies wildly from system to system and depends even more on the individual monitor settings, which are usually all over the place, especially for CRTs. You can do only two things about it:

- Standardize all your images for 2.2 from the get go and let the Mac users deal with the difference. As a good form, include a gray wedge somewhere, along with a very brief epxlantion.

- Accept the fact that virtually every viewer will see something different. That's the nature of the Web and there is nothing we can do about it.

That's all, I hope this helps. I also appologize for the long-winded post, but the topic is to complex for brief explanation.

[Steve Kefford]

I would suggest that you convert your images to sRGB rather than just tag them. That is as much control as you can have. I would also question your fact 3. I don't know about macs, but with Windows, provided the OS supports it, colour management is on. It is not, AFAIK, a configurable option.

I guess one option would be to reduce the contrast of the images so you dont have deep shadows or extreme highlights.

Steve

[David_Senesac]

One has no control currently over the display characteristics of other's personal computer monitors. However web display of images is improving year by year as more people get behind the 2.2 Windows gamma value. Also due to the explosion in digital cameras and associated computer applications, ordinary people at home are more likely to calibrate their monitors. However I think one ought to ignore monitors in many workplaces because color rendering on such monitors is rarely a business necessity as they tend to just run traditional business computer applications. Thus are set up by sys admin folk rather crudely as manufacturers provided.

I think there is a way out of the current situation. That would be to produce cheap calibrated color targets for less than say $5 a sheet. Of course Gretag McBeth and X-Rite have forever had a stranglehold on color targets while the IT8.7 target systems have always been pricy and hard to deal with. And I'm not talking about highly calibrated ones or ones that will last ten years. Rather just something the average CMS ignorant person can buy over the counter at any camera store and use as a comparison image to an easily available standard digital file they can download online. The online file might have an IT8-7 image on for example or any of the others.

Thus a person would download the file then display it on their monitor under prescribed viewing conditions, in order to make a crude evaluation via comparison of their monitor characteristics. As someone in computer engineering for a couple decades I only know too well how monitors tend to vary. Even calibrated ones today often are not as color balanced as people think because at the low consumer end, colorimeters and spectrometers are pretty crude with some aging quickly. Fortunately monitor adjustment functionality on the new LCD monitors is more easily incorporated. Thus more users have the capability to adjust their monitors by comparison alone that can result in reasonable displays. Most monitors I see are so grossly off that anything would be an improvement.

So Bill Gates, Dells, HPs etc how about doing something useful for all your users? If you even provided a crude color chart with each new computer it would go a long ways. ...David

[Steve Kefford]

A lot of this assumes that a user wants to calibrate his/her monitor. For non-imaging appliations a calibrated monitor is not necessarily the best option. In typical office conditions with bright flourescent lighting a calibrated monitor will be rather dull and a hinderence. This highlights the fact that a calibrated monitor is only half the story. Ambient conditions are just as important.

Steve

[Marko]

Most of this assumes that a user knows what calibrating the monitor is and why is it needed.

Most average folks (those who are not engineers, graphic artists and such) can't adjust the refresh rate on their CRTs properly. I've seen many who simply can't see the difference when shown! The entire concept of calibrating colors would be simply too exotic for them to bother, especially since it needs more than one click.

[David_Senesac]

Steve, I'd agree in office conditions calibration for images doesn't make sense and that is why I rejected a need to do so in the business environment.

Marko, you're correct about how little the average user knows, however that is certainly changing. However just about everybody today has a little digital camera, is looking at images online, printing things out on their $99 inkjet printers at home, or having prints made from kiosks at their local Walmart etc. Thus many are becoming aware of some problems with color when they come home with pics where everyone's face looks green. The industry producing all this high tech stuff is certainly not going to require everyone to buy monitor calibration aps? They may do nothing as has been the status quo but I'm betting some wise minds will eventually figure out something cheap like my idea. Better yet will be when cheap self calibration screen sensor IC's are incorporated into monitor designs. It could be done today and should be but consumer electronic designs tend to be controlled by companies only with near term profit motivations. ...David

[Stephen Willard]

I have one "check station" in a local eye glass store. They just purchased two new Apple iMacs. It is clear to me that they have not calibrated their computers. I would guess they are using the factory default, and I estimate the gamma is about 1.4.

I have two PC check stations I visit, and I guess the gamma for those systems are around 2.5 or more. Out of the six systems I visit only one looks like it may have been calibrated for viewing images on the web. The others do not have a clue.

If you are using your website informally then this is not a big deal. Just calibrate your gamma at 2.2 and use the color profile sRGB. However, if you are trying to sell images over the web then this is a serious problem. If the images do not look good then they will not sell!

[Marko]

If you are using your website informally then this is not a big deal. Just calibrate your gamma at 2.2 and use the color profile sRGB. However, if you are trying to sell images over the web then this is a serious problem. If the images do not look good then they will not sell!

Stephen, it is less of a problem than it may seem at a first glance. It is actually a problem that alleviates itself to a good extent, strange as it may sound.

Human vision in general and color perception in particular is very adaptive - the brain "knows" that your shirt is white and sees it as such whether you stand in shadow under the deep, blue sky or under the mercury street light in the evening. A person with normal vision, especially one that is unaware of these finer points we are discussing here, will see every image on every website they visit through the same distorted color and gamma setting, and thus will be so accustomed to it that their brain will see your images almost as you intended.

That leaves you with only two things you can do about it and one you shouldn't: Fine tune your images to look their best under gamma 2.2, convert them to sRGB and don't worry any further. :)