[TYPO3-english] How to edit a 8-bit PNG graphic with colortype 6 = RGB+alpha?

[Martin Bless]

Hi,

>Perhaps you could provide a link to such an image that causes
>you headache

I found peace of mind by now but still have questions:


(1) Question: How to "roundtrip" PSD -> PNG -> PSD?

Use one layer "white" and set opacity to 65%. Then save as 8-bit
PNG with transparency: Fine!

Now, open that PNG with Photoshop again and you'll find a half
transparent layer with 100% opacity. 

Q: How can you find out with means of Photoshop what the original
RGB values of the color and the original opacity percentage is? I
still have no answer to this. If somebody has, let us know!

And be assured, the PNG does contain that information! In my case
it was in the palette as (255, 255, 255, 204), that's "white" with
opacity 204.0/256*100 = 79.6875 = approx. 80% opacity.


(2) Image like transparency information and Photoshop ...

This was more lack of knowledge of mine. I was looking for a
function "Create alpha channel with transparency information" from
image. CS5 now has such an option directly in the menu (something
like "Create layer from transparency". With my CS4 I can do it
manually: Select and copy everything. Then the selection contains
the transparency information. With that you can do a paste in a
mask layer. It is just not really an intuitive procedure ...

Martin

-- 
Certified TYPO3 Integrator | TYPO3 Documentation Team Member

http://mbless.de