ocr: Figure 4B: High-Boost Filtering (After): A7x7 median filter is used first to isolate low-trequency information. The result is subtracted from the original image (figure 4A) to produce a high- frequency image. This high-frequency image was added back to produce this figure, with the equivalent of a 1.5 amplification factor. Notice the contrast in the facial features (such as the eyes and teeth) is strengthened and the wisps of hair on the right side of the face are more distinct. On the negative side, two specks of white (noise) have appeared which are probably the result of tiny flecks of pape ...
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