Saving converted images without applying the alpha layer

[psycosyd]

Greetings all,

I have been struggling with this problem for a while now. It seems simple enough but I am not quite able to create the result I want. I am currently trying to convert an image to a psd type to be opened later. When I do a straight conversion the alpha layer is applied to the resulting images, so I lose the original full image. For example, using the tutorials found at http://www.imagemagick.org/Usage/masking/#alpha_off I have as my background the resulting image of the "convert moon.png -alpha off alpha_off.png" command. My alpha layer creates the first image, with the moon. When I do my image conversion, the resulting psd has the alpha layer I want (that would create the moon shape) but the rbg image also has applied the alpha, and so I dont preserve the original full image background, only what is under the white part of my alpha layer.

It is not enough for me to use:

convert moon.png -alpha off -alpha set alpha_set.psd

as then my alpha layer is lost and saved as completely opaque and white.

I had thought to use the above command and then use Dst_In with the initial image to copy the alpha layer but once again I get the same problem I had before, where I lose the background image without the alpha layer.

So, I was wondering if anyone could clue me in on how to solve this... hopefully I explained things well enough too.

Thanks for the help!

[fmw42]

I am not sure I understand what you are trying to do. It might be best to post links to your input image and any test result images with your command line and then explain what it is you want to have as a result.

Please note that PSD images have two kinds of transparency -- background transparency and alpha channel transparency. IM currently can only handle the alpha channel transparency. So if your input image has background transparency then you may be out of luck.

[psycosyd]

I figured it would be a bit confusing

Here is my initial image, in this example it happens to be a tga.

http://www.freeimagehosting.net/0d350

As you can see, there are the rbg channels and the alpha channel.

This is the result after my basic convert command
convert original_image.tga final.psd

http://www.freeimagehosting.net/e7873

As you can see, the rgb channels have applied the alpha layer, and the original image is lost.

Now if I do the command
convert original_image.tga -alpha off -alpha on final.psd
I get the following
http://www.freeimagehosting.net/fd40e

Which, as can be seen, I have preserved my rgb image but lost the alpha channel.

[fmw42]

can you post a link to your input image, not the screen snap, so others can test with it.

It would appear that IM is applying the alpha channel into background transparency in the PSD conversion and keeping the alpha channel.

I would note that IM's PSD and TIFF transparency processing has a number of known bugs and issues with dealing with both background and alpha transparency.

[psycosyd]

here it is, a tga for my initial test

http://myfreefilehosting.com/f/4aeddee0ec_0.44MB

EDIT: For reference, I am using the most recent version of IM, 6.7.1.

[fmw42]

here it is, a tga for my initial test

http://myfreefilehosting.com/f/4aeddee0ec_0.44MB

EDIT: For reference, I am using the most recent version of IM, 6.7.1.

I get your same result when going to PSD. The alpha channel is both converted to background transparency and kept as an alpha channel.

However, it seems to work correctly when going to TIFF and viewing in my old PS CS.

convert jedisquirrels.tga jedisquirrels.tiff

[psycosyd]

Yeah, I get that result as well, but I really need it as PSD... so it may be that IM is not going to be my solution this time. That would be too bad too.

[fmw42]

You could try using EXIFTOOL to edit the psd file to tell it that it does not have background transparency. I was going to try that, but it looks like my exiftool install is corrupt and I will have to reinstall first before I can test that.

[fmw42]

Perhaps you should report this on the Bugs forum.