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 variance within the local window must be greater than a certain threshold to effectively enhance the image.

Explanation:

• Mean: The local mean calculates the average intensity of the pixels within a specific neighborhood or window.
• Variance: The variance measures how spread out the pixel values are within the local neighborhood. High variance indicates more texture or contrast, while low variance indicates smooth, uniform regions.

The Key Condition:

• Enhancement is applied more effectively in regions with higher variance. This is because high variance typically corresponds to areas with more detailed features, such as edges or textures, which can be enhanced to improve contrast.
• Low variance areas, typically smooth or uniform regions, do not undergo significant enhancement to avoid amplifying noise or unnecessary contrast in featureless regions.

Thus, local enhancement is triggered when the variance exceeds a predefined threshold, ensuring that only regions with meaningful texture or contrast are enhanced.