Sony DVD Rom/DVD Video - Manual (Page 17)

2. DVD V
ideo
17
2.3.19 Image Size
Each highlight on any page should be contained in
its own separate TIFF file. Each image should only
be as big as the text or graphic itself and should not
have any white space around the graphic. It should
also be big enough to include the registration mark.
Please make sure to always supply two images of
the same dimensions per highlight, one with and
one without registration mark.This allows closer pla-
cement of highlights on the page, as highlight files
cannot overlap in a DVD menu.
One file that contains all the highlights for a page
should also be provided. The colour depth and file
format for this file should be the same as the other
highlight files. Sample below.
2.3.15 Interlacing
(Flicker/Jitter)
A video frame is made up of two video fields. These two
fields are interlaced and each contains half of the infor-
mation required to display the frame. Due to timing
drifts in video equipment, the two fields do not interlace
perfectly causing the flicker/jitter commonly seen on
sharp edges and fine lines.
This is more evident in horizontal lines than vertical.
This problem is not evident on computer displays
because they are usually non-interlaced.
To avoid these flicker/jitter problems, thin (e.g. single
pixel) horizontal lines should be avoided and the overall
image should be blurred, using either gaussian or other
suitable methods.
2.3.16 File Format
The preferred file formats for menu background delivery
are uncompressed TIFF or as video on a separate tape.
If the artwork is made in Adobe Photoshop, it must be
saved in PC format with no compression. Some gra-
phics packages save an alpha channel with a 24bit file.
DO NOT save the alpha channel.
2.3.17 Naming Convention
For efficient and clear processing of the menu items, the
following naming convention should be applied:
2.3.18 Registration and
Alignment
To facilitate positioning and alignment of high-
lights/overlays on the backgrounds at Sony DADC,
a file with registration marks should also be supplied
with the main background file. This file should con-
tain clearly visible registration marks in addition to
artwork in the menu background file.
The registration marks can be of any type as long as
they are accurate to one pixel width and height. They
should also be of a colour that makes them stand out
from the background.
The accompanying highlights/overlays should have a
matching registration mark in a colour of the palette,
which has not yet been used. This is discussed in
detail later.
Menu
background
without…
…and with
registration
marks