How to get accurate color after uploading

paulblock · August 2, 2005

I've been on pbase for a time and am trying out Smugmug to see about making the switch. While I love the ease of use and other Smugmug features, I'm concerned about what appears to be slightly inaccurate color display after uploading. Here's what I'm seeing. I have downsized large images to 800x wide pixels and 72 dpi and saved. Then I upload those images to my
"recent" photos gallery on smugmug at http://paulblock.smugmug.com and my "recent photos gallery on pbase at http://www.pbase.com/paulblock. I then open the same picture in large size (so it displays at the full 800x wide) in separate windows on the two, and I also open the original 800x wide file in both Photoshop CS2 and Preview (this is on a Mac under OSX Tiger). The pbase and both originals (Photoshop and Preview) are exactly identical. The smugmug is just the slightest bit duller (grayer). I then download the images back to my harddrive and compared them, and still the pbase is exact but the smugmug image is slightly duller. Furthermore, the smugmug file is smaller in size, whereas the pbase is the exact same as the original. This tells me that the image has been changed when I upload an 800x wide image to smugmug, and during this recomposition the color shifts slightly. I redid the test by saving the same image in Photoshop and having it not embed the sRGB color profile. This makes no difference.

I'd like to upload images already cropped to 800x and have smugmug display the exact file I upload. Is this possible, or will smugmug always reprocess the file? Is there some way to ensure the image displayed on smugmug is exactly what I upload, colorwise? Any info would be greatly appreciated.

Paul Block

paulblock · August 2, 2005

Addendum: How to get accurate color after uploading
I've done some more reading of the help docs, and smugmug claims that if I size the photo just under 801px on the largest size, it will use that photo exact photo and will not recrop, so folks will see what I have uploaded. This is NOT what my tests show me on numerous uploads. While smugmug does not appear to resize my 800px-wide horizontal images (or 800px-high vertical ones), it is compressing it and causing a slight color change. I have already done my own sharpening and compression to bring a 3+ megapixel image from an 8MP Canon 20D camera down to about 90K or so, and the smugmug file ends up shrunk another 15 percent or so. When I download the image back to my hard drive from smugmug, the resulting file is always smaller. A file that is 96K (96,840 bytes) that I then upload to smugmug and pbase and then download back again comes back at that exact same number of bytes from pbase but only 80K (78,227 bytes) from smugmug. While the help screen indicates that smugmug uses my original for the large image, since it is smaller than 800px on the largest size), this isn't precisely correct. The file appears to be recompressed, and the resulting image is a bit duller. I see this over and over again. Is there a way to ensure my carefully prepared images will be used intact? The file I have created is far, far smaller than if I uploaded the full 3MB original and let smugmug create the large, which ends up being something like 200K.

Baldy · August 3, 2005

Hi Paul,

I think there are two issues at work. One is that although we love the Mac and I worked for Steve Jobs for two years, it's bad at rendering color accurately and consistenly on the Internet.

Read it and weep.

My guess is you're using Safari and your Mac is rendering sRGB files differently when an ICC profile is embedded and when it's not.

In a few minutes I'll investigate why we're processing your photo instead of leaving it untouched and post another response.

Thanks,
Chris
smugmug

Baldy · August 3, 2005

Hi Paul,

I analyzed 3 versions of this image and here's what I found:

http://paulblock.smugmug.com/gallery/702381/1/30620088/Original

The PBase version is 101K. The smugmug version, linked above (note how the URL ends in the word Original) is also 101k and they are byte-for-byte identical.

The smugmug version that ends in Large is 61K:

http://paulblock.smugmug.com/gallery/702381/1/30620088/Large

The large would normally be the only version a visitor to your gallery would see, unless they knew how to manipulate our URL to say Original at the end like I did.

None of the photographic bits were changed on the Large version, so it's identical to the Original except for the metadata attached to it, which we stripped for viewing on the Internet. Why would we do that? Because it adds a 40K load (9 seconds for a 56k modem user) but doesn't add any value to them. For example, the original has an embedded thumbnail which is just dead weight for someone viewing your photo on the Internet.

Here's the breakdown of the metadata in that photo:

JFIF 14 bytes
Exif 15934 bytes
Photoshop IRB 23158 bytes
Adobe APP 1412 bytes

And there were a couple of other things as well.

So why did it look slightly different in color to you? It wouldn't to anyone on a PC or consumer device like TV, handheld, etc. It's missing the ICC profile, which only Safari tries to read. if your Mac isn't set up to render sRGB files the same color whether it has an ICC profile or not, which is the way it should work, you get a color shift.

ICC profiles are useful for pre-press work, but they don't fly on the Internet. Here's why:

http://blogs.smugmug.com/great-prints/2005/06/25/why-icc-profiles-dont-fly-on-the-internet/

Clear as mud? I hope this helps.

Thanks,
Chris
smugmug

James Broome · August 3, 2005

Baldy wrote:

None of the photographic bits were changed on the Large version, so it's identical to the Original except for the metadata attached to it, which we stripped for viewing on the Internet. Why would we do that? Because it adds a 40K load (9 seconds for a 56k modem user) but doesn't add any value to them. For example, the original has an embedded thumbnail which is just dead weight for someone viewing your photo on the Internet.

Here's the breakdown of the metadata in that photo:

JFIF 14 bytes
Exif 15934 bytes
Photoshop IRB 23158 bytes
Adobe APP 1412 bytes

And there were a couple of other things as well.

So why did it look slightly different in color to you? It wouldn't to anyone on a PC or consumer device like TV, handheld, etc. It's missing the ICC profile, which only Safari tries to read. if your Mac isn't set up to render sRGB files the same color whether it has an ICC profile or not, which is the way it should work, you get a color shift.

I'm not directly involved in this issue, but thanks for writing this up. There's some outstanding info there and I'm sure it'll help me.

delenca · August 3, 2005

Baldy wrote:

Hi Paul,

I think there are two issues at work. One is that although we love the Mac and I worked for Steve Jobs for two years, it's bad at rendering color accurately and consistenly on the Internet.

Read it and weep.

My guess is you're using Safari and your Mac is rendering sRGB files differently when an ICC profile is embedded and when it's not.

Thanks,
Chris
smugmug

Hi Chris,
I had read that reference ("read it and weep") and I thought I understood the implication - make sure to include the sRGB ICC profile with your picture when you upload. But that's not right - what you are saying is that since smugmug (and probably all other online sharing sites) strip the EXIF data (including ICC profile) when it generates the Large/Medium/Small thumbnails, those pictures will ALL look different to users of Safari on Macs (which, of course, is the default browser in Macs).

. I am speachless. I know you like Macs and all (I did once too) but that's just terrible... Truly a case to weep. So, now I have to worry about how the pictures will look to Mac viewers... because the default behavior of the default web browser in Macs is NOT to adopt the standard/default color profile on the internet... And people continue to insist Macs are easier to use... Sigh.

Of course, the ideal situation would be to convince the powers that be (with your connections, Chris...) to change the behavior on Safari. But is there another solution? Would be possible to strip the EXIF information while keeping just the ICC profile info without significantly increasing the size of the file? That would be great - you could say: "smugmug is the only photo sharing site that is viewed correctly by both Macs and PCs..." A pipe dream, I suppose...

-Alex

jfriend · August 3, 2005

Embedded profiles cause different behavior on Mac vs. PC

delenca wrote:

Of course, the ideal situation would be to convince the powers that be (with your connections, Chris...) to change the behavior on Safari. But is there another solution? Would be possible to strip the EXIF information while keeping just the ICC profile info without significantly increasing the size of the file? That would be great - you could say: "smugmug is the only photo sharing site that is viewed correctly by both Macs and PCs..." A pipe dream, I suppose...

Delenca, a quick question for you. Are you interested in making your smugmug images look the same for all viewers whether they are using a Mac browser or a windows browser?

If you are, then your image cannot rely on an embedded ICC profile, not even on a Mac. Since Safari will use one if it's in the image and all browsers on the PC will not use one, you have to either strip it out or make sure it's the standard sRGB profile. If you do anything differently, your images will display differently in Safari than they will in IE on the PC.

I can't tell from this thread whether you understand this point or whether you are arguing for a different objective. Smugmug seems to be arguing that they want all images to look the same no matter which platform/browser they are viewed on and wants them to print the same too. From what I can see of their work, they are adopting policies on their site consistent with that objective. Supporting embedded ICC profiles would not be consistent with that objective because it would cause things to render differently on the Mac than anywhere else.

--John

paulblock · August 3, 2005

Chris:

Thank you for the wonderfully detailed explanation. It will take a bit of studying on my part, but I think understanding this process will resolve my issues. Yes, I'm on a Mac using Safari. It sounds as if most folks (PC users) aren't seeing things exactly as I expect even on my pbase account. The real solution may be for me to review how I am processing, so that my screen version looks the way I want without the ICC profile. Then it should display the way I want on both PC and Mac. I really like the way your galleries work, and as a test I've had all my galleries exactly the same on pbase and smugmug this past week, and I've had folks at work looking at my newest photos on each. So far, almost all prefer the way the gallery works on smugmug. I'll definitely pay for the full year (my trial account runs out in a day or so). And I may well upgrade to a pro account in the coming weeks and have my paulblock.com domain become my smugmug account. Thanks again for taking such time and effort to analyze and explain.

Paul

Matthew Saville · August 3, 2005

paulblock wrote:

Chris:

Thank you for the wonderfully detailed explanation. It will take a bit of studying on my part, but I think understanding this process will resolve my issues. Yes, I'm on a Mac using Safari. It sounds as if most folks (PC users) aren't seeing things exactly as I expect even on my pbase account. The real solution may be for me to review how I am processing, so that my screen version looks the way I want without the ICC profile. Then it should display the way I want on both PC and Mac. I really like the way your galleries work, and as a test I've had all my galleries exactly the same on pbase and smugmug this past week, and I've had folks at work looking at my newest photos on each. So far, almost all prefer the way the gallery works on smugmug. I'll definitely pay for the full year (my trial account runs out in a day or so). And I may well upgrade to a pro account in the coming weeks and have my paulblock.com domain become my smugmug account. Thanks again for taking such time and effort to analyze and explain.

Paul

What about macs that have IE? My girlfriend's Mac has Safari AND IE...

On another note, what about the smaller files that smugmug DOES create? I'd really like to see an improvement in the quality of the M and L jpeg files, from my experimentation they seem to be equal to a photoshop jpeg level 5 in quality. Isn't it just like, a few K difference from a 5 to a 7 or 8? Sometimes I get BIG artifacts if I'm uploading a picture with a really smooth blue sky contrasting with something sharp and jagged...

Anyways that's just a small tangent. I hope to some day own a Mac.

My uncle who works at IDEO hangs out with Steve Jobs by the way, lol...

-Matt-

delenca · August 4, 2005

jfriend wrote:

Delenca, a quick question for you. Are you interested in making your smugmug images look the same for all viewers whether they are using a Mac browser or a windows browser?

Yes, I would like the images to look the same to Mac and Win browsers. I think we all would! (Side-note: I don't actually have "Smugmug images" anymore b/c I ended up choosing imageevent. I like a lot about smugmug, especially the excellent service, but I don't like the quality of the M and L images created. The thumbnails suffer from too many jaggies and haloes due to the level of sharpening and compression chosen by smugmug (and discussed in other threads). I have had extensive discussions with Chris in this regard, who was very helpful in explaining the reasonings for smugmug's decisions on how to process the images. I hope to get back to smugmug at some point, which is why I keep an eye on what's going on here.)

jfriend wrote:

If you are, then your image cannot rely on an embedded ICC profile, not even on a Mac. Since Safari will use one if it's in the image and all browsers on the PC will not use one, you have to either strip it out or make sure it's the standard sRGB profile. If you do anything differently, your images will display differently in Safari than they will in IE on the PC.
I can't tell from this thread whether you understand this point or whether you are arguing for a different objective.

Sorry, perhaps I wasn't clear. The embedded ICC profile I meant was the standard sRGB profile. I originally assumed that by including the sRGB profile in all my images, they would get color-managed identically across all browsers. But Chris' message in this thread clued me in - since the thumbnails are stripped of the sRGB ICC profile, Safari will assume that the color profile for the thumbnails is "monitor" rather than sRGB. That's what I find stunning. And, thus, my suggested "hack" to avoid the problem.

jfriend wrote:

Smugmug seems to be arguing that they want all images to look the same no matter which platform/browser they are viewed on and wants them to print the same too. From what I can see of their work, they are adopting policies on their site consistent with that objective. Supporting embedded ICC profiles would not be consistent with that objective because it would cause things to render differently on the Mac than anywhere else.
--John

Well, but right now, it doesn't really work - since smugmug strips the sRGB ICC profile info from the thumbnails, Safari users will see the image differently from PC users (unless they know to change the default setting). Granted, this is true of other online photo sites too (like pbase and imageevent) and really caused by the fact that the Safari design does not default to the color space that is standard for web images. Nevertheless, it's disapointing that it's another thing to worry about (besides different monitor calibration, etc, etc) - and, thus, my question on whether it would be possible to preserve the sRGB information in the generated thumbnails.

Just a thought. Kudos again to Chris for all the information.
-Alex

Baldy · August 4, 2005

Getting the Mac to look like a PC is tough, unfortunately. Apple chose to go with a monitor gamma of 1.8 instead of sRGB's 2.2 standard, so photos look lighter on a Mac.

Then there's the fact that the 3 different mac browsers act 4 different ways.... Someone mentioned IE. Like Safari but unlike Firefox, it will do the right thing when an ICC profile is present. But unlike Safari, it assumes files are sRGB if no profile is present (that's what browsers are supposed to do). However, it only does it if you know to go into options and activate Colorsync.

So there's really no way to know what people are seeing on a Mac.

My editorial: it's because of the pre-press experts who've spent 20 years in the complex world of magazine and brochure production and have no experience in consumer networks. They had undue influence on Apple because Apple sold so many computers into those markets.

colourbox · August 4, 2005

I am a (mostly happy) Mac user and my approach is to calibrate my monitor to 2.2, convert Web graphics to sRGB, and write off the Mac viewers. The reason is that's how everybody else operates, from news sites to online catalogs, so Mac viewers are already used to seeing the gamma 2.2 Web through their 1.8 monitors. Besides, if Apple fixes Safari later, the problem will solve itself - I feel I should not try too hard to compensate for something that's broken, and then have my work look sub-optimal when it's fixed. Yes, it's sort of like coding CSS with IE6 around...

The best thing every Mac user can do to make images that look good everywhere else is to convert images to sRGB, which is at gamma 2.2. Going the other way, the best thing every Mac user can do to view the Web the way the rest of the world does is to use your Displays preference to profile your monitor at gamma 2.2. That way Safari probably has a better chance of making images look the way they're supposed to.

I don't agree that it's the prepress experts' fault. I can't think of any reason prepress people would have said "Oh, and why don't you assume a person's specific monitor profile is what everybody else sees, and why don't you think of other ways to screw up color management and be non-standard." Apple did it to themselves. Prepress experts, being so concerned with good color, would have said "Do it so that the best color shows up in the most places." Apple is supposed to be pushing ColorSync as a competitive advantage but they keep doing screwy things to Safari and iPhoto lately. Very puzzling.

Despite the accusation that prepress is pushing consumer-unfriendly color spaces and profiling, a few years ago when color management was so foreign to the workflows, much of the prepress world was telling people to shut off color management and strip out all profiles (sound familiar?). While it's not so forbidden to them now, a typical prepress person is probably more likely to agree with smugmug that on systems that don't interact perfectly, profiles can cause more problems than they solve.

How to get accurate color after uploading

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