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 in the local neighborhood must be above a certain threshold for enhancement to be applied.

Explanation:

• Mean: The local mean determines the average intensity of the pixels in the neighborhood around a given pixel.
• Variance: The local variance measures how much the pixel intensities deviate from the mean. A high variance indicates that the neighborhood has high contrast (with edges, textures, or details), while low variance suggests a smooth, uniform area.

Condition:

• Threshold Variance: Enhancement is typically applied when the variance exceeds a certain threshold, indicating that the region has enough variation in pixel intensities to enhance. In areas with low variance (smooth regions), enhancement might not be applied, or it would be minimal, as it may lead to noise amplification.

This ensures that enhancement is focused on areas with enough texture or contrast to benefit from the enhancement process, rather than applying it to uniform or featureless regions.