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 local variance must be greater than a certain threshold to apply enhancement effectively.

Explanation:

• Mean: The local mean adjusts the overall brightness in a specific neighborhood around each pixel.
• Variance: The local variance measures the spread or contrast of pixel values in the neighborhood. A higher variance indicates a region with more details (e.g., edges or textures), while a lower variance indicates smooth or uniform regions.

Condition for Enhancement:

• Variance Threshold: Enhancement is most effective in regions with high variance, as they contain more detailed features that can be enhanced. When the variance is low (i.e., the region is uniform or smooth), little to no enhancement is applied to avoid accentuating noise.

In summary, local enhancement using mean and variance works best when the variance is above a certain threshold, ensuring enhancement is applied to regions with significant texture or contrast.