For a local enhancement using mean and variance, there is one condition: ms(x, y) ≤ k0 MG, where, MG is global mean, k0 a constant and ms(x, y) a measure of gray value as light or dark at point (x, y). Then, which fact is true for k0?

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 local variance must be greater than a threshold value to apply meaningful enhancement.

Explanation:

• Mean: The local mean provides the average intensity of pixels within a given neighborhood.
• Variance: The local variance measures how spread out the pixel values are from the mean, indicating contrast or texture within the region.

Condition:

• Variance Threshold: Enhancement is applied primarily in regions with higher variance, as these regions contain more detail, such as edges or textures, which can benefit from enhancement. If the variance is too low (indicating a smooth, featureless region), enhancement may not be applied or would be minimal to avoid amplifying noise.

Thus, local enhancement using mean and variance is effective when the variance exceeds a certain threshold, ensuring the enhancement targets regions with sufficient contrast or texture.