JPEG, what's the deal?

[hoodmeister]

JPEG's ~ Great, huh? Perfect for the internet, due to their diminutive size and good quality.

But, on occasion, I have serious issues when trying to JPEG my photos. Mostly it's just artifacting, which can generally be solved by increasing the quality of the JPEG, but I also sometimes get saturation / hue issues, where the colours of things change significantly through the JPEG process.

Case in point (beware, the PNG is a LARGE file! :

Compressed JPEG (100% quality)

Uncompressed PNG (>3.5MB!)

Please note ~ Another thing I don't understand is that these images both look exactly the same when viewed direct (With Firefox here). You need to save them to desktop, and view them with Windows picture / fax viewer to see the effects I describe.


The ridges in the sheeps fur lose quite a lot of detail... But I can live with that, and it's nowhere near as bad as it was with higher JPEG compressions... A fair bit of contrast goes bye bye too. But the grass, it's completely changed colour! No longer is it the crisp fresh dark green, but an altogethor more unhealthy yellow. Nasty.

I've tried a few programs, but to avail. Is this just something I have to live with? Or is there something I can do to combat the effects?

[limpduck]

both images look the same to me, evan tested in photoshop cant see any major changes like you describe. some loss in contrast buts thats expected with the jpeg.

if your using photoshop check your gamma, colour profiles, or check on a crt if using a tft.

[eldren]

Haven't looked at your images, but from what you describe, I've an idea of what you mean. A colleague here at work showed me the same thing a few weeks ago - a picture of two cars in a show room. View it in FF, and they're a cool blue colour, with blue lighting and grays. View the same file in IE, and they're red with grays. This happened on his XP SP2 and my Win2K SP4 system.

No clue what's wrong or how to fix it, though. I'm not certain it's JPEG's fault so much as the program rendering it. I'd assume IE and the Windows image viewer share the same JPEG library, which would explain why both of them render it with the same colours. Good luck. :/

[specofdust]

Hoodi I might be being stupid here, but I think its more a case of windows fax and picture veiwer being crap at rendering jpegs, I find alot of the time with jpegs they cant be drawn, I zoom in one factor, they draw fine, in Opera, they're all fine first time, its just windows fax and picture viewer thats a bit useless. Try ACDC as a replacement

Anyway, having looked at them bother in windows, and opera, I'd say they both look the same, in both :/

[hoodmeister]

You're all right, in everything but windows picture & fax viewer, the images look identical :<

I feel like a lemon, please slap me now.

Perhaps it's just the picture and fax viewers dodgy rendering of PNG's that's the issue here... It's not rendering them "correctly" and the result is something "wrong" but that I prefer

[unrealrocks]

I think the quality loss is down to the fact Windows Picture viewer seems to interpolate images, not only when you zoom, but when its being viewed at 100%!

[DeludedGuy]

Im using IE here at work, and the images look pretty much identical. The JPEG is a little brighter.

*Slaps hoodmeister*

[hoodmeister]

Progress!

I'm having the same issue with more and more photos... And have found that embedding an "ICC profile" (don't know what this is) in photoshop makes JPG's have the right colours, at least when viewed from photoshop / windows picture & fax viewer. This still goes out the window when viewing images with a web browser, though :/

New example of this, here's a JPEG with an "ICC profile" embedded. Viewed here with IE / FF it doesn't look how I want it to. Take particular note of the lower leaves, and the kind of yellowy hue they have :



Now, save that image to your desktop, and then view it with windows picture & fax viewer / photoshop. Compare the lower leaves. They're far greener now, which is how I want it, and how I processed the image...

[Nemeliza]

Originally Posted by hoodmeister

Now, save that image to your desktop, and then view it with windows picture & fax viewer / photoshop. Compare the lower leaves. They're far greener now, which is how I want it, and how I processed the image...

look in FF, IE, PS 7(used embedded profile, and disgarded), and picture viewer...they all look the same

IN PS converted profile did however make a difference, although not huge it did look better.

[hoodmeister]

It's not a massive difference, it's just highly annoying to spend some time processing an image, to find that they lose some punch when I finally save them...

Still, anybody got any idea how to avoid it? Can I set my photoshop to use a standard profile, so that what I process is what I get?

[limpduck]

There so many factors when looking at images online that tbh it may not be worth the effort, you can use a £2000 professional colour sync'ed monitor, but it wont help much due to fact most people who look at it will be using some cheap 15" tft with brightness and contast turned to 100% with some weird gamma settings to boot.

[hoodmeister]

Still driving me nuts, but i've found a completely farcial workaround ~ Print Screen.

At least it works :/

[shiato storm]

i found if I tried to work in adobe 1998 colour space and save as jpeg, when viewed in picture/fax viewer its really over saturated...
I suspect I need to fidle around and calibrate my monitor a bit better