Adaptive filter device and related method

An adaptive filter device comprising:

• first means for deciding which of a first segment and a second segment of an input picture signal more correlates to a third segment of the input picture signal, the third signal segment being of interest, the first signal segment preceding the third signal segment by a 4-field interval, the second signal segment following the third signal segment by a 4-field interval;
• second means for calculating a difference between the third signal segment and the more-correlating signal segment which is decided by the first means for every pixel related to the input picture signal;
• third means for mixing every 1-pixel-corresponding portion of the third signal segment and every 1-pixel-corresponding portion of the more-correlating signal segment which is decided by the first means into a 1-pixel-corresponding portion of a first filtering-resultant picture signal at a mixing ratio depending on the difference calculated by the second means;
• fourth means for deciding which of a fourth segment and a fifth segment of the first filtering-resultant signal generated by the third means more correlates to a sixth segment of the first filtering-resultant picture signal, the sixth signal segment being of interest, the fourth signal segment preceding the sixth signal segment by a 2-field interval, the fifth signal segment following the sixth signal segment by a 2-field interval;
• fifth means for calculating a difference between the sixth signal segment and the more-correlating signal segment which is decided by the fourth means for every pixel related to the first filtering-resultant picture signal;
• and
• sixth means for mixing every 1-pixel-corresponding portion of the sixth signal segment and every 1-pixel-corresponding portion of the more-correlating signal segment which is decided by the fourth means into a 1-pixel-corresponding portion of a second filtering-resultant picture signal at a mixing ratio depending on the difference calculated by the fifth means.