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 key condition is:

The variance within the local window must exceed a certain threshold to perform effective enhancement.

Explanation:

1. Local Mean: The local mean helps in determining the average intensity in a given neighborhood (window) around a pixel.

2. Local Variance: The local variance measures the spread or contrast of pixel intensities within that window. High variance indicates that the region contains detailed features like edges or textures, while low variance suggests smooth or uniform regions.

Condition for Effective Enhancement:

• Variance Threshold: Enhancement is most effective in regions with high variance, as these areas have more detail that can be accentuated. In regions with low variance, which typically correspond to smooth or flat regions, little to no enhancement is applied.

Thus, the condition is that only regions with a sufficiently high variance undergo significant enhancement to improve the image contrast without amplifying noise in uniform areas.