Color profile problems on Macintosh

[arnulf]

I've already posted a question about my problems concerning color profile when uploading

photos to PN. If I have understood things correctly, PN removes all file information,

<i>including</i> color profile, on uploaded photos. Apparently, this is great for PCs, but

on my Mac, the colors seem a lot paler on the site than if I upload the same photo to any

other site than PN. I have tried several other browsers (Camino, Omniweb, IE), and the

result is always the same. The images look dull.

<p>

I'm wondering wether it's something I do on my computer that makes only my images look

pale, or if I see all photos on PN with different saturation than people have uploaded them.

Since I've already accused some of my fellow photographer friends of pale shots, I would

like to know if I was in my right to do so.

<p>

So, my question is: Are there any Mac users out there who have experienced similar

things? Is there something I can do to make the colors appear right?

<p>

Desperately waiting for an answer.

<p>

arnulf

[mottershead]

Make sure the image is in the sRGB color space before you upload it to photo.net, and you should not have any problem. If there is no color profile in the image, then your browser will default it to something. I don't know what that is, but I would bet on sRGB. Since that is what the image actually is, the image will then look the same displayed in your browser from photo.net as it would if you displayed it in your browser or in Photoshop from your hard disk.

 

If you don't convert it to sRGB before uploading it, when the color profile is stripped out, your browser won't know what it is and will assume the default (as I said, probably sRGB), and it will look wrong.

[photomark]

Brian, as you may or may not know, Safari is aware of color profiles and makes use of

them. When there is no profile, however, safari does not default to sRGB. Looking at

untagged images in Safari, my best guess is that it just sends the raw rgb data to the

monitor--in effect showing the image in the context of your monitors profile. Since Safari

is color profile-savy, a good way to get reasonably (as reasonable as you can on the web)

consistent color among calibrated systems is to convert images to sRGB and save them

with a profile. This allows applications like safari to use the profile while providing

reasonable rgb numbers for non-aware applications whose default is close to the sRGB

color space. Of course, if photo.net is stripping the profile from uploaded images then this

option is not available which is a shame considering a profile only adds a couple K to the

image size.

 

Arnulf, much of the tone shift in images is probably coming from the fact that your system

is using a different gamma than the pc. You can calibrate your monitor to use a 2.2

gamma, which is not a bad idea anyway, and will make untagged sRGB images look less

washed-out on your screen. This may make some of the OS things like icons a little darker

but you will get used to is quickly.

[mottershead]

Mark, I knew that Safari and other browsers on the Mac supported color profiles, but I did not know that they had no default, effectively providing no conversion when the color profile is not specified. It seems to me that this is a bad design decision, that any image on the web has a reasonable chance of being sRGB, since that is what browsers on other platforms assume, and that there is almost zero chance that the color profile of the monitor would be the correct choice.

 

The reason that we strip out the non-image data is that some types of non-image data cause problems in browsers. In particular, versions of IE 6 will break if presented with XML-encoded preview data. I don't know that color profile information causes problems, but the program that we have for stripping out non-image data can't distinguish between the various types of non-image data.

[scott_clarke]

I use both Mac and PC, and have some trouble sometimes with the Mac. Alot of times I don't see the problem until I see it on the PC later. Like Arnulf it is most often color, but also density. I have now got in the habit of checking it on the PC before I put in critique. If I don't someone will be all over it. Thanks for the question and response. It is much help to me. Regards to you both.

[minicucci]

Arnulf:

 

One thing you can try is to setup PSCS' Save-For-The-Web to display the JPG using "Standard

Windows Color". In theory, this will alert you to any problems before you post. Just click on

the little triangle in the upper right corner as shown in the attached and select the Windows

option.

 

I also agree that it is best to calibrate your monitor to a 2.2 gamma versus the traditional 1.8

gamma of the Mac. It is a 2.2 gamma world out there.

[minicucci]

Oops. Here's the JPG.<div></div>

[arnulf]

Thanks to you all for your help. Changing the gamma certainly helped a lot. Patricia's save-

for-web tip is also very helpful.

<p>

I still don't understand what the point of stripping the images for their color profile is, but I

guess you guys know what you're doing...

<p>

arnulf

[johncrosley]

Patricia,

 

I have Windows only, and I cannot reproduce the menu you have posted. I have chosen 'JPEG' and 'maximum' but your posting is too small for me to see what you have chosen for the two boxes on the left under 'Preset' and what is filled in under 'preset' I can see you have quality at '100' blur at '0' and Matte is not filled in at all, while 'progressive is checked and ICC profile is checked.

 

I must be missing something.

 

Can you please attach to a post a full-size copy of your attachment, above, or e-mail me a full-size copy at johncrosley@photo.net so I can see if I can reproduce the menu choices on a Windows version of Photoshop CS2 or discover if it's just missing entirely from the latest Windows version.

 

Thanks in advance. Let me know if this presents a problem; I am ever so grateful for the help members provide one another and the clues I get, even now as a 2-year+ member.

 

******

 

To the member (whose name is obscured as I write this) who inquired about why it was necessary to strip out certain info from photo files.

 

Brian's answer above should have sufficed.

 

However, I have some recollection from long-ago earlier posts of his. His prior answers were that not stripping out the data caused certain Internet Explorer 6 versions just to crash -- they wouldn't function, which is a disaster for a photo site.

 

I seem to recall that the problem is accumulative, that such crashes are not immediate and their potential builds up over time as a person browses photos with that file data, and then suddenly thge browser stops without warning.

 

That is very bad for business for a photo site, since members quickly download hundreds, thousands and more thumbnails in one or more browsing sessions (and many 'hibernate' their Windows computers, thus not interrupting their browsing sessions; until they shut down their computer, their cumulative 'views' are one long browsing session, I divine, helping make matters potentially worse.

 

So, I recall (I think) Brian made a point that the 'crashes' were the result of an 'error' compounded by multiple cumulative views overloading some IE browser function -- leading to a browser crash.

 

Brian can step in if I've wrongly remembered or explained it.

 

John (Crosley)

[minicucci]

If you click on the first entry (a TIFF file), just before the Oops posting, the image is full size.

If that does not work, let me know and I'll email it. This is Save For the Web, powered by PS'

ImageReady application. Not sure if it is the same for WIndows. The menu I was showing

Arnulf is displayed when you click on the little triangle at the upper right of the image

window. Again, it might look different in Windows.

 

The preset just says "Unnamed" because I've been too lazy to name it. I always use the same

settings.

[arnulf]

Wouldn't it be possible then to first strip the image for all information and then convert to

sRGB? Would that be too unpractical? Sorry if I'm asking stupid questions here, I just think it's

annoying that the colors don't look right.

[minicucci]

Arnulf: You might take a look at this thread:

http://www.photo.net/photo/4314774

sRGB tightly compresses transitions from one color to another, which can lead to a range of

issues when your editing space is a larger gamut that sRGB (and everything has a larger

gamut than sRGB).

 

Stripping data and then converting is no solution, unless I misunderstand you question. To

do so, you'd have to resave a JPG, which would introduce a host of other quality questions

quite apart from color and all in trade for no benefit that I know of.

[arnulf]

Thanks Patricia for the link. I'm not going to pretend I'm anywhere near understanding all of

it, but it certainly helped me realizing the extent of the problem. Guess I'll just have to learn

more about color management and -theory.

[alberto.conde]

Again, Patricia makes a worthy, enlightening contribution to a question. I do wish that many photo.netters were as gentle and learned as she is.<p>Perhaps she would be as gentle and contribute an answr to a question of mine weeks ago that had the privilege of getting zero answers...<p>In any case, even if she does or cannot, thanks a lot, Pat!