ARC130S SECTION
4
ARC130S 060801 Version 1 Issue 1
4.23
CC
Raster aspect ratio -
Number(s)
Aspect Ratio of the full raster when correctly
displayed expressed as a two digit abbreviated
numeric value where the comparison ratio is
against a height of 9. 12 is used for 4 by 3 (12 by
9)
i.e.
Two digit number(s) giving the
a
spect ratio of
entire picture / raster / graphics bitmap, including
all the black of any Letterbox or Pillarbox area, that
gives a correctly displayed image.
Numbers describing ratios seen in use at present
are 12, 14, 15 (Super16), 16, 17 (1.85:1), 21
(2.35:1Cinemascope), 24.
e.g. A 16 : 9 full height “anamorphic” raster is
shown as
16
.
A request for material suitable for 16 by 9 TX could
just be “supply it in F16 format”.
Examples of common aspect ratios expressed as
two digit numbers using this notation.
Aspect Ratio
Two Digit Number
4:3
12
14:9
14
15:9
15
16:9
16
1.85:1
17
Generally:
If the aspect ratio is expressed as: -
A : B
(width to height)
Then the two digit number N representing the
comparison ratio against a height of 9 will be given
by
N
9
B
x A
=
or by transposing
B =
9
N
x A
and
A
B
9
x N
=
Full Raster
Area
