Enhancement and Filtering

Five questions. Choose one answer for each, then submit to see your score and explanations.

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1. Which explanation matches brightness, contrast, and clipping?A. Global equalization uses one mapping for the entire image.B. For an averaging filter, equal weights add neighboring values and divide by their count.C. A Gaussian filter computes a weighted average, with nearby pixels usually receiving greater weight.D. A simple brightness change adds a constant.

2. Which explanation matches histogram equalization and local contrast?A. A simple brightness change adds a constant.B. For an averaging filter, equal weights add neighboring values and divide by their count.C. Global equalization uses one mapping for the entire image.D. A Gaussian filter computes a weighted average, with nearby pixels usually receiving greater weight.

3. Which explanation matches convolution: let neighboring pixels help?A. A simple brightness change adds a constant.B. For an averaging filter, equal weights add neighboring values and divide by their count.C. Global equalization uses one mapping for the entire image.D. A Gaussian filter computes a weighted average, with nearby pixels usually receiving greater weight.

4. Compare global equalization and a mild local contrast setting on one shadowed image. Inspect a flat background and a detailed region separately.A. Record whether real edges become clearer, whether background noise grows, and whether colors shift. Choose settings based on those observations, not only the overall appearance.B. The last value becomes 225, not 240. Clipping made the operation irreversible for that pixel.C. The average is 40. Averaging gives every sample influence, so a single extreme value can pull the output away from the surrounding level.D. The answer depends on the noise and line width. Compare line continuity and thickness, not only the smoothness of the background.

5. Use the same two filters on a noisy image containing a thin line. Which result best preserves the line?A. The last value becomes 225, not 240. Clipping made the operation irreversible for that pixel.B. Record whether real edges become clearer, whether background noise grows, and whether colors shift. Choose settings based on those observations, not only the overall appearance.C. The average is 40. Averaging gives every sample influence, so a single extreme value can pull the output away from the surrounding level.D. The answer depends on the noise and line width. Compare line continuity and thickness, not only the smoothness of the background.

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Enhancement and Filtering

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