iDVD '09 (7.x): Preparing images for iDVD slideshows
You can use photos, movies, presentation slides (created in a program such as Keynote), or other image files in a slideshow created in iDVD. iDVD works with any image file that is supported by QuickTime (including PICT, JPEG, TIFF, and PDF.) You can also use photos directly from your iPhoto library.
Images and movies in a slideshow are scaled to fit the standard DVD window size, but the aspect ratio is preserved. For example, a picture taken vertically (also known as “portrait format”) may have black bands on either side of it to fill out the screen. If you want an image to fit the DVD window exactly, use an image-editing application to resize the image before bringing it into iDVD. (It is not possible to resize movies.) Resize to these dimensions:
720 x 540 pixels for standard video in NTSC format
854 x 480 pixels for widescreen in NTSC format
768 x 576 pixels for standard video in PAL format
1024 x 576 pixels for widescreen in PAL format
You can also make sure images in iDVD are always scaled to a size that will fit within the area visible on most TV screens, or the “TV safe area.”
To fit slides into the TV safe area:
Choose iDVD > Preferences.
Select the checkbox labeled “Always scale slides to TV Safe Area.”