use clouds from Terraformer as overlay ?

JimP

Well, I did figure out how to use the cloud maps a foreground image on my world all maps using html div...

How do I make the areas that aren't clouds, transparent so viewers can see the ground below the clouds ?

Thanks.

Monsen

I believe that might be a bit difficult. The files are jpg files without transparency information, so there are no transparent sections in the file at all. FT uses the complete file, not as a n image, but as a transparency map when it uses it for overlays, something you cannot easily do in HTML.

You'll probably need to create a new image (solid white), and somehow use the cloud image as a transparency channel for that image. Problem is, I have no idea how to do that. Maybe Photoshop has some way of doing this.

JimP

I did look in Irfanview, but didn't spot anything in there for changing transparency.

Monsen

I don't think you can use Irfanview for this. It is a far more complicated procedure than most simple editors supports. Advanced packages like Photoshop might be able to do this, but that's just me guessing, as I am not skilled in Photoshop (Both to expensive to buy and too difficult to use IMHO)

Monsen

Here JimP, I figured out how to do this in Gimp:
http://www.gimpusers.com/forums/gimp-user/10832-alpha-from-image

For the RGB image mentioned in the tutorial, you'll probably want an image consisting of just plain white. Then save it as .png which supports alpha transparency. This should cause you to end up with a transparent cloud image you can use as an overlay in HTML or basically anywhere else.

JimP

OKay, I'll check into it. Thanks.