For a local enhancement using mean and variance, there is one condition: σs(x, y) ≤ k2DG, where, MDG is global standard deviation, k2 a positive constant and σs(x, y) a measure of contrast at point (x, y). Then, which fact is true for k2 if its values is less than 1.0?

Question

For a local enhancement using mean and variance, there is one condition:

Answer 1

For local enhancement using mean and variance, the key condition is:

The local variance must be sufficiently high to apply enhancement effectively.

Explanation:

• Mean: The mean of a local region provides the average intensity within that neighborhood. It helps in adjusting the brightness of the region.

• Variance: The variance measures how spread out the intensity values are within the local neighborhood. High variance indicates that the region contains more detailed features, like edges or textures, whereas low variance indicates smooth or uniform areas.

Condition for Local Enhancement:

• Local enhancement using mean and variance is typically more effective when the variance is high. This is because high variance indicates that there are more details or contrast in the region, which can be enhanced. In areas where the variance is low (i.e., the region is uniform or smooth), enhancement is less useful or may be avoided.

In summary, the enhancement is applied only when the variance of the local region exceeds a certain threshold to ensure that features are enhanced without exaggerating noise in flat regions.