Video signal processing apparatus and method
A video signal processing apparatus generates first to third correlation values based on five sequential video line signals C(n−2) to C(n+2) that include two kinds of color-difference signals transmitted line sequentially. The first correlation value indicates degree of similarity between C(n+1) and C(n−1), the second correlation value indicates degree of similarity between C(n+2) and C(n), and the third correlation value indicates degree of similarity between C(n) and C(n−2). When the degree of similarity between C(n+1) and C(n−1) is evaluated to be smaller than a predetermined level based on the first correlation value, the apparatus determines a mixing ratio of C(n+1) and C(n−1) according to relative magnitude of the third correlation value with respect to the second correlation value. The apparatus outputs a mixed signal obtained by mixing the signals C(n+1) and C(n−1) according to the mixing ratio and the video signal C(n) as two simultaneous color-difference signals.
1 . A video signal processing apparatus comprising:
a correlation value generation unit configured to generate a first, a second and a third correlation values based on five sequential video line signals C(n−2) to C(n+2) that include two kinds of color-difference signals transmitted line sequentially, the first correlation value indicating a degree of similarity between the signals C(n+1) and C(n−1), the second correlation value indicating a degree of similarity between the signals C(n+2) and C(n), and the third correlation value indicating a degree of similarity between the signals C(n) and C(n−2),
a mixing ratio generation unit that generates a mixing ratio of the signals C(n+1) and C(n−1) according to a relative magnitude of the third correlation value with respect to the second correlation value when the degree of similarity between the signals C(n+1) and C(n−1) is evaluated to be smaller than a predetermined level based on the first correlation value;
a signal mixing unit that mixes the signals C(n+1) and C(n−1) according to the mixing ratio; and
an output unit that outputs a signal mixed by the signal mixing unit and the signal C(n) as two simultaneous color-difference signals.
2 . The video signal processing apparatus according to claim 1 , wherein when the degree of similarity between the signals C(n+1) and C(n−1) is evaluated to be larger than the predetermined level, the mixing ratio generation unit generates the mixing ratio to be a predetermined value regardless of the second and the third correlation values.
3 . The video signal processing apparatus according to claim 1 , wherein
the second correlation value is an absolute difference D 2 between the signals C(n+2) and C(n),
the third correlation value is an absolute difference D 3 between the signals C(n) and C(n−2), and
when the degree of similarity between the signals C(n+1) and C(n−1) is evaluated to be smaller than the predetermined level, the signal mixing unit mixes the signals C(n+1) and C(n−1) by the following formula.
D
3
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C
(
n
+
1
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+
D
2
×
C
(
n
-
1
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D
2
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D
3
4 . A method of processing a video signal comprising:
generating a first, a second and a third correlation values based on five sequential video line signals C(n−2) to C(n+2) that include two kinds of color-difference signals transmitted line sequentially, the first correlation value indicating a degree of similarity between the signals C(n+1) and C(n−1), the second correlation value indicating a degree of similarity between the signals C(n+2) and C(n), and the third correlation value indicating a degree of similarity between the signals C(n) and C(n−2);
determining a mixing ratio of the signals C(n+1) and C(n−1) according to a relative magnitude of the third correlation value with respect to the second correlation value when the degree of similarity between the signals C(n+1) and C(n−1) is evaluated to be smaller than a predetermined level based on the first correlation value;
mixing the signals C(n+1) and C(n−1) according to the mixing ratio; and
outputting a signal obtained by said mixing and the signal C(n) as two simultaneous color-difference signals.
5 . The method according to claim 4 , further comprising:
determining the mixing ratio to be a predetermined value regardless of the second and the third correlation values when the degree of similarity between the signals C(n+1) and C(n−1) is evaluated to be larger than the predetermined level.
6 . The method according to claim 4 , wherein
the second correlation value is an absolute difference D 2 between the signals C(n+2) and C(n),
the third correlation value is an absolute difference D 3 between the signals C(n) and C(n−2), and
when the degree of similarity between the signals C(n+1) and C(n−1) is evaluated to be smaller than the predetermined level, the signals C(n+1) and C(n−1) are mixed by the following formula.
D
3
×
C
(
n
+
1
)
+
D
2
×
C
(
n
-
1
)
D
2
+
D
3