Help needed writing greyscale PSD files

Hello

I’m not an experienced Photoshop user and I’m trying to write out some multi-layered psd files from a proprietary application. I’m using my own code and the Adobe PhotoShop file format description to do this.
The resultant file is mostly right but my user complains that the layers are partially locked and he has to duplicate them to unlock them. Looking at the file in PS, I notice that the layer names in the Layer palette are italicised suggesting that PS regards them as Background layers. It’s not at all clear to me what I’m missing or what I’m writing incorrectly. By experimenting, I find that if I change the transparency of the layer to less than 100% or the layer type from "normal" to anything else then the layer is no longer locked.

I wondered if someone who has some experience in successfully writing multilayered greyscale PSD files could advise me of possible errors/omissions I might be making.

Alternatively, can anyone tell me what precisely denotes a layer as Background in the PSD file? If I take a file with a single background layer then this layer is locked. If I double click the layer on the layer-palette and replace the background layer with a new layer then I still have a single layer but the new layer is no longer locked. What is the significant change in the file which says that this layer is no longer a background layer?
Many Thanks
Fred

Don’t know if this will help…

In Photoshop, when you use Layer>Flatten Image all the information on the layers is put onto the Background layer. There is no longer any transparency and you can not save the PSD file with Layers checked.
You may be writting code for a flattened file with layers. Something you can not do within Photoshop.

Hello

I’m not an experienced Photoshop user and I’m trying to write out some multi-layered psd files from a proprietary application. I’m using my own code and the Adobe PhotoShop file format description to do this.
The resultant file is mostly right but my user complains that the layers are partially locked and he has to duplicate them to unlock them. Looking at the file in PS, I notice that the layer names in the Layer palette are italicised suggesting that PS regards them as Background layers. It’s not at all clear to me what I’m missing or what I’m writing incorrectly. By experimenting, I find that if I change the transparency of the layer to less than 100% or the layer type from "normal" to anything else then the layer is no longer locked.

I wondered if someone who has some experience in successfully writing multilayered greyscale PSD files could advise me of possible errors/omissions I might be making.

I just made a tiny ps image (4×4 pixels) and saved it as is and after I converted the background to a layer.
When I checked the saved files with a hex editor I found that file content is different at and after address 0x1358. This is probably the offset, at which layer information is stored, because shortly behind this address the layer name is written into the file. I’d suggest you do the same and compare data in this area to the specs of the file format and to the content of the files your application produces. HTH,

"Peter Wollenberg" wrote in message

…

Unfortunately this doesn’t seem to solve my problem. Even if I explicitly set all the protection bits to zero (which is the default anyway) then my layers are still "partially locked" whenever I set their type to normal and their transparency to fully opaque. I only get this problem with greyscale images and not rgb images – very strange.

"Fred" wrote:

BTW, the ADOBE developper forum might be a better place to ask that kind of questions.

Do you have any further info on the ADOBE developer forum – is it run by Adobe for example?

Hello

I’m not an experienced Photoshop user and I’m trying to write out

multi-layered psd files from a proprietary application. I’m using my

code and the Adobe PhotoShop file format description to do this.
The resultant file is mostly right but my user complains that the

partially locked ….

Many Thanks
Fred

This may or may not help, but I have written a program that can inspect and dump PSD files in some detail; source code is available at http://www.telegraphics.com.au/svn/psdparse/ (Subversion repository).

"toby" wrote in message

This may or may not help, but I have written a program that can

and dump PSD files in some detail; source code is available at http://www.telegraphics.com.au/svn/psdparse/ (Subversion

Thanks – that looks like it could be really useful.

But I’m afraid I’m not familiar with Subversion…
If I follow the links to Subversion on the above Url, should I be

download a set of code

…that I can build in Windows 2000 using Visual Studio?

Will I need to install some other apps as well?

Thanks for your help

Fred

Fred wrote:

No; it’s self-contained. And to save you the trouble of building it, here’s a pre-built DOS console app that produces a verbose dump: http://www.telegraphics.com.au/sw/files/psddump-1.3b3-win.zi p