Patent ID: 7302112

Claim:
An edge enhancer apparatus comprising: extracting means for extracting, from an input video signal, edge components comprising at least a low-frequency component, a middle-frequency component and a high-frequency component; coefficient generating means for generating coefficients corresponding to amplitudes of the edge components; correcting means for correcting the edge components with the coefficients corresponding to the edge components, the correcting means configured to limit the corrected edge components to a predetermined maximum value; and combining means for combining the corrected edge components; wherein the correcting means multiplies the edge components by the corresponding coefficients; wherein the combining means adds the corrected edge components together; and wherein the coefficient generating means includes: absolute value calculating means for calculating absolute values of the edge components; and peak value detecting means for detecting peak values of the absolute values, wherein the peak values are held for a predetermined period corresponding to an interval between a rise and fall of the edge components, and wherein low-frequency edge components, middle-frequency edge components and high-frequency edge components are amplified separately to corresponding values proportional to squares of the low-frequency edge components, middle-frequency edge components and high-frequency edge components such that the larger the amplitude of the original edge component, the larger the coefficient by which the edge component is multiplied.