Just seen this slightly odd issue. Take a look at this image (http://www.c3s.co.uk/images2/deveron220601.jpg) in a web browser, then save it to HD and open it in Photoshop. When I do that, the red bit on the LHS has nasty jaggies (http://www.c3s.co.uk/images2/deveron220601_ps.jpg) as though it wasn't anti-aliased properly when it was rendered - but it looks fine in Opera, IE and Firefox. Paint Shop Pro also shows the jaggies, but Fireworks renders it smoothly.

And no comments about the image content, it's from a friend who likes drawing space ships and asked me what was going on! :)

Any ideas?

Il sent u a PSD with a smooth edge, that is some strange stuff :S

I can create a smooth version easily enough - just done that by opening the jpg in Irfanview and saving as PNG. Wonder what's going on though, it's odd that this one then looks perfect in Photoshop! :)

Could be a lil misunderstanding between the original compressors output and the decompressors in the other programms, i know jpg's use smoothing (blur?!) to make things look errrrm smoo...better :)

the damndest thing!

you are absolutely right.

what application is the actual jpg image created in?

What I think is happening here is that the browsers are better at rendering 'progressive' jpegs - photoshop displays image 'as is'?

The image was created in 3ds max v7.5.

From what I understand, the jpg format doesn't blur deliberately but the lossy part of the compression comes from downsampling high-frequency brightness data - plus the fact that it is tiled into 8x8 pixel squares. I would have thought that the decompressing algorithm should be perfect and repeatable between programs though! (progressive or not)

He has solved his problem by saving to another format, importing to PS and then saving as jpg. I'm more interested in why it's happening though!

I'd say that its a defect in the JPEG rendering in the application. Or maybe a legacy compression method that has been superceded.

But what concerns me most is the discrepancy between Fireworks and PS. That is irritating.

Yeah, I'd already wondered if it was some slightly unusual option - I think the jpg spec is quite complex, but you'd hope it would be handled properly in an expensive graphics program! I think the main thing that worries me is that I always assume Photoshop is "right" out of all the applications I use. Or are PS/PSP right and the other programs wrong??

Looks fine here in PS 7 and CS. But the port and starboard markers are on the wrong sides though:|

Unless, of course, it's not a rear view:)

Originally posted by GMAN
Looks fine here in PS 7 and CS.
Really? I thought it was fine at first until I looked closely at the anti-aliasing (or lack of) between the red and grey. But if it looks the same in IE (for example) and PS on your pc, wonder if there's something even weirder than I thought going on...

Think I know what's going on here.

Photoshop isn't using the same decompression methods as your web browser and other image viewers.

Photoshop is actually rendering the image correctly, while the web browsers are applying extra filters to smooth out the JPG.