Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Absolute scales for subjective evaluations of image quality.
| Quality Scale | Obstacle Scale | ||
|---|---|---|---|
| 5 points | No image degradation is noticed | 5 | Very good |
| 4 points | Can see changes in image quality without hindering viewing | 4 | Good |
| 3 points | It is clear that the image quality has deteriorated, which slightly hinders viewing | 3 | Common |
| 2 points | Obstructs viewing | 2 | Bad |
| 1 points | Very serious hindrance to viewing | 1 | Very bad |
