Blue stripes artifacts

[jenne1978]

Hi there everyone,
A student of mine made a picture with a leaf cameraback and it was ok apart from this (see attachement) Does anyone know what caused it? It does only appear on her photoshop, not mine. Hers is CS5, mine is CS6 and CC. It does not appear in camera raw. The screenshot is from her photoshop.

[Manfred M]

We would have to see the original Photoshop (*.psd) file. My guess is that there is a layer with the blue bands in that file that may have inadvertently been introduced to the image. There has obviously been some image manipulation (i.e. the frame has been put around the image).

[jenne1978]

The frame is just the photoshop workspace I included when I cut out the picture with snipping tool. There was no manipulation involved. The blue stripes are artifacts. The question remains what kind of artifacts.

[Manfred M]

The frame is just the photoshop workspace I included when I cut out the picture with snipping tool. There was no manipulation involved. The blue stripes are artifacts. The question remains what kind of artifacts.

Very strange indeed. The only time I've seen anything resembling those stripes is when the computer is acting up. Have you tried a cold boot on the machine to see if it still does this? The only way I can think of diagnosing this is if you can figure out how to replicate the problem.

[dje]

It certainly is very strange. It looks like some problem between CS5 and the graphics card in the computer although if it is only happening on this image then that theory is probably not valid.

What does the image look like if it is exported from CS5 as say a jpeg ?

Manfred's suggestion of a re-boot is worthwhile trying. If you really get desperate you could try a re-install of CS5 and even a driver update for the graphics card.

Dave

[revi]

There are several other (less likely) possibilities as well:
- It might have been a read error while loading the file.
- It might have been due to a race condition somewhere in the process, if CS5 is multi-threaded; multi-threading is very hard to get 100% correct,
and errors can show up only every now and then under special conditions (timing...), and can seem to be non-reproducible.

You say that the blue bands show up on your student's computer with CS5, but not with camera raw, nor on your computer. Do they still show after a restart of CS5 or a reboot of her machine?

Like Manfred said, the only way to really diagnose the problem requires you to be able to reproduce it while noting exactly what you do...

Remco

[Manfred M]

- It might have been due to a race condition somewhere in the process, if CS5 is multi-threaded; multi-threading is very hard to get 100% correct,
and errors can show up only every now and then under special conditions (timing...), and can seem to be non-reproducible.

Photoshop is not multi-threaded. I believe that Adobe Media Encoder is the only multi-threaded application in CS5.

The other possibility is that the machine has a non-compliant video card or driver as CS5 does use GPU video acceleration for some functionality like zooming, image rotation, etc. It also uses OpenGL for other more basic functionality.

[jenne1978]

That's a lot of information! thanks GrumpyDiver, Revi and Dje. It will remain a mystery because it is not my computer but it does shed some light in the darkness.