Transparent layers are only supported on a few file formats, of course.
That said, there are a number of programs available that allow you to optimize your images, often *greatly* reducing file size. For example, if you use Windows you might look at the freeware selections at http://www.snapfiles.com. They have a category called "Image Compression" under Graphic Tools--and you can choose from a variety of programs depending upon your needs. The same site also has some graphic editors that allow for image compression as a built-in function. Similar tools exist for other operating systems as well. HTH David On 6/13/06, Georg Baum <[EMAIL PROTECTED]> wrote:
Paul Smith wrote: > Dear All > > I have taken a screen-shot of a certain window containing an intricate > figure. Around the figure everything is white. Then I thought that > changing the white to transparent, I would get a picture with a > smaller size, which would lead to a pdf document with a smaller size > too. Can this be achieved? If yes, how? I always use gimp for this: Image->Autocrop image works fine (except when there are some nonwhite pixels left, e.g. from a scan, but then I erase them before. Georg