Editing Preferred number (section)

== Computer engineering ==
When dimensioning computer components, the powers of two are frequently used as preferred numbers:

  1    2    4    8   16   32   64  128  256  512  1024 ...

Where a finer grading is needed, additional preferred numbers are obtained by multiplying a power of two with a small odd integer:

      1  2   4   8   16    32    64    128   256    512    1024 ...
 (×3) 3  6   12  24  48    96    192   384   768    1536   3072 ...
 (×5) 5  10  20  40  80    160   320   640   1280   2560   5120 ...
 (×7) 7  14  28  56  112   224   448   896   1792   3584   7168 ...

{| class="wikitable" align="right"
|+ Preferred aspect ratios
! !! 16: !! 15: !! 12:
<!--| (2²)² || 3 × 5 || 2² × 3-->
|-
! :8 <!--|| 2<sup>3</sup>-->
| 2:1 ||     || 3:2
|-
! :9<!--|| 3²-->
|16:9 || 5:3 || 4:3
|-
! :10<!--|| 2 × 5-->
| 8:5 || 3:2 || <!--not preferred-->
|-
! :12<!--|| 2² × 3-->
| 4:3 || 5:4 || 1:1
|}
In [[computer graphics]], widths and heights of [[Raster graphics|raster images]] are preferred to be multiples of 16, as many compression algorithms ([[JPEG]], [[MPEG]]) divide ''color'' images into square blocks of that size. Black-and-white JPEG images are divided into 8×8 blocks. Screen resolutions often follow the same principle. 
Preferred [[aspect ratio]]s have also an important influence here, e.g., 2:1, 3:2, 4:3, 5:3, 5:4, 8:5, 16:9.