Consider the images shown. The image on the right was obtained by lowpass filtering the im...

Consider the images shown. The image on the right was obtained by lowpass filtering the image on the left with a Gaussian lowpass filter and then highpass filtering the result with a Gaussian highpass filter. The dimension of the images is 420 × 344, and D0 = 25 was used for both filters.

(a) Explain why the center part of the finger ring in the figure on the right appears so bright and solid, considering that the dominant characteristic of the filtered image consists of edges on the outer boundary of objects (e.g., fingers, wrist bones) with a darker area in between. In other words, would you not expect the highpass filter to render the constant area inside the ring dark, since a highpass filter eliminates the dc term?

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(b) Do you think the result would have been different if the order of the filtering process had been reversed?