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 condition is:

The variance in the local region must be greater than zero (non-zero) to apply meaningful enhancement.

Explanation:

• Mean: The local mean provides the average intensity of pixels within a specified neighborhood.
• Variance: The variance measures how much pixel intensities deviate from the mean. A non-zero variance indicates that the local region contains some contrast or variation in intensity.

Condition for Enhancement:

• Non-zero variance: Enhancement is more effective in areas where there is some variation in pixel intensities. A zero variance indicates a uniform region with no contrast (e.g., a solid color), where enhancement may not be necessary or beneficial.

In summary, local enhancement using mean and variance is applied only when there is variation (non-zero variance) in the local region, ensuring that the enhancement targets regions with texture or contrast rather than uniform, featureless areas.