Digital Signal Processing Reference
In-Depth Information
4K Digital Cinema
4096 × 2160
1080p
1920 × 1080
720p
1280 × 720
480i/p
720 × 480
Figure 5.1.
5.1 Understanding Video Scaling
Video scaling, whether upscaling or downscaling, is the
process of generating pixels that did not exist in the original
image. To illustrate this, let's look at a simple example: scaling
a2
4 pixel image, as shown in
Figure 5.2
.
In the “New Image” the white pixels are pixels from the “Existing
Image” and the black pixels are those that need to be generated
from the existing pixels.
There are many methods for generating new pixels: the
simplest is called the nearest neighbor method, or 1
2 pixel image to a 4
1 inter-
polation. In this method a new pixel value is simply equal to the
Nearest Neighbor
Bilinear Scaling
Existing Image
New Image
Figure 5.2. A 2 x 2 pixel image is enlarged (upscale) to a 4 x 4 pixel image.
