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 greater 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 condition is:

The variance must be above a certain threshold to apply meaningful enhancement.

Explanation:

• Mean: The local mean helps adjust the overall brightness of a region by calculating the average pixel intensity within a defined neighborhood.
• Variance: The local variance measures the spread of pixel intensities from the mean, indicating the level of contrast or texture in the region.

Condition:

• Variance Threshold: Enhancement is applied more effectively when the variance is sufficiently high, as regions with high variance contain more contrast or texture (e.g., edges or details). When the variance is low, indicating smooth or uniform regions, enhancement may not be needed or could lead to noise amplification.

Thus, local enhancement is applied when the variance exceeds a certain threshold, ensuring that only regions with sufficient detail or contrast are enhanced.