APPARATUS FOR IMPROVING SHARPNESS OF IMAGE
First Claim
1. An apparatus for improving sharpness of an image, the apparatus comprising:
- an edge detector calculating an edge value of each pixel of an input image using brightness relation with neighboring pixels;
an effective edge judging unit determining, as effective edge pixels, pixels having an edge value between a first threshold value and a second threshold value set in advance among pixels of the input image;
an effective edge classifying unit determining, as weak edge pixels, pixels having an edge value smaller than a third threshold value set in advance among the effective edge pixels, and determining, as strong edge pixels, pixels having an edge value greater than the third threshold value among the effective edge pixels;
an isolated edge judging unit judging an isolated edge pixel included in an isolated edge among the effective edge pixels;
a 2-dimensional (D) high pass filter (HPF) applying unit applying a first 2-D HPF having a first gain to the weak edge pixels excluding the isolated edge pixel, and applying a second 2-D HPF having a second gain smaller than the first gain to the strong edge pixels excluding the isolated edge pixel to generate edge strengthening values of respective pixels; and
an edge strengthening value applying unit adding the edge strengthening values to brightness values of the respective pixels of the input image.
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Abstract
Provided is an apparatus for improving the sharpness of an image. The apparatus includes an edge detector, an effective edge judging unit, an effective edge classifying unit, an isolated edge judging unit, and a 2-D HPF applying unit. The edge detector calculates an edge value using brightness relation with neighboring pixels with respect to each of pixels of an input image. The effective edge judging unit determines effective edge pixels. The effective edge classifying unit determines weak edge pixels and strong edge pixels. The isolated edge judging unit judges an isolated edge pixel included in an isolated edge. The 2-D HPF applying unit applies a first 2-D HPF to the weak edge pixels, and applies a second 2-D HPF to the strong edge pixels to generate edge strengthening values. The edge strengthening value applying unit adds the edge strengthening values to brightness values of the respective pixels of the input image.
15 Citations
7 Claims
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1. An apparatus for improving sharpness of an image, the apparatus comprising:
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an edge detector calculating an edge value of each pixel of an input image using brightness relation with neighboring pixels; an effective edge judging unit determining, as effective edge pixels, pixels having an edge value between a first threshold value and a second threshold value set in advance among pixels of the input image; an effective edge classifying unit determining, as weak edge pixels, pixels having an edge value smaller than a third threshold value set in advance among the effective edge pixels, and determining, as strong edge pixels, pixels having an edge value greater than the third threshold value among the effective edge pixels; an isolated edge judging unit judging an isolated edge pixel included in an isolated edge among the effective edge pixels; a 2-dimensional (D) high pass filter (HPF) applying unit applying a first 2-D HPF having a first gain to the weak edge pixels excluding the isolated edge pixel, and applying a second 2-D HPF having a second gain smaller than the first gain to the strong edge pixels excluding the isolated edge pixel to generate edge strengthening values of respective pixels; and an edge strengthening value applying unit adding the edge strengthening values to brightness values of the respective pixels of the input image. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification