Preparation

Postscript Problems

Presentation

Before giving a presentation you should use the dlb to produce a dlb document of your presentation slides just as, for instance, in PowerPoint. You may use either dlb's drawing tools for the slide production or external tools which can produce Postscript or GIFs. The postscript or GIF images can be imported into the dlb either by using "Insert->Image" or "Insert->PS Direct". Both commands can be used to import postscript. If you know the orientation of your postscript document in advance, please set the correct rotation value in "View->Image Orientation" before importing the postscript slides. Otherwise, you will have to change the orientation of each imported slide by hand. Save your presentation slides as a dlb document. 

Notice: If your are using pixmaps (GIFs etc.), you will have a loss in quality when zooming a page.

Using Postscript as a presentation format often comes along with a lot of  problems. This concerns specifically postscript which has been produced  with Windows applications.  We achieved best results with Windows95 and the "Apple Laserwriter 4.00" driver. Choose "Optimal Portability" as driver option. However, there are still problems.

Before giving a presentation, make sure that your postscript slides are rendered properly with the dlb. For some known problems there exist workarounds:

• Older versions of gs are sometimes not compatible with the dlb. Make sure that you have installed a newer release (>v4) of ghostscript on your system.
• The right border of Landscape-oriented postscript slides which have been produced with Windows applications is often not visible. There are two possible solutions:
• Try to apply the Unix tool "pstops" to your original postscript document by  typing
   "pstops 1: input.ps output.ps".
  Then import the modified postscript document into the dlb.
• Instead of Using "Insert->PS Direct" you can also try to import postscript files as images by using "Insert->Image". Each Postscript slide is transformed to a pixmap prior to rotate it to Landscape. Rotation is done pixel-wise. 

Notice: 
• If your are using this option, rendering of postscript is a little bit slower than with "PS Direct". Furthermore, the quality is degraded slightly when using zoom factors above and below 100%.
• The dlb uses "PS Direct" per default when loading a dlb document which contains postscript. In order to render the postscript content of a dlb document as an image, disable "View->Use PS Direct" prior to loading the dlb document.
• For many other problems, it it sometimes helpful to convert a postscript file to a pdf file which is then again converted back to a postscript file. Use the tools "ps2pdf" and "pdf2ps".
• For postscript documents with more than one page, the dlb uses "pssplit" to compress and split the postscript document into separated pages. pssplit does not always work properly and sometimes produces white pages. There are two solutions:
• Use "pssplit" by hand (command line) to split your postscript document. Use "psselect" to pick out the critical pages. Then import your postscript slides page by page into the dlb. Don't forget to compress the slides by using "lzps". This reduces transmission time.
• Use "psselect" to pick out all pages. Compress pages by hand with "lzps". Notice: "lzps" and "pssplit" are included in the dlb distribution.

If your are using a software which can produce pixmaps of your slides instead of postscript, try this option. The dlb can import most of the common image formats. PowerPoint, for instance, produces excellent GIFs of a presentation when using the included HTML assistant. 

Load your prepared dlb document into dlb's workspace. Your pages are created locally. You can then transmit the pages to the group by using the double-arrow button above the local page list.

If you have postscript included in your document and don't want to use direct rendering, disable "View->Use PS Direct" prior to loading your dlb document (see above). Postscript is now automatically transformed to pixmaps by using the built-in ImageMagick library.

Use the telepointer and graphical annotations to illustrate your presentation. This makes it easier for the remote participants to follow your presentation.