To obtain an image filter for output characteristics having a steep peak, using a simple configuration.
The image filter is provided with a first filter part 20a and a second filter part 20b, having different frequency characteristics respectively, a subtracting part 20c for subtracting the absolute value component of an input image signal passing through the second filter part 20b from the absolute value component of an input signal passing through the first filter part 20a, and a 0-clipping part 20d for replacing a negative component in an output signal from the subtracting part 20c with 0. The first filter part 20a has an output characteristic such that it makes a frequency band component containing a specific spatial frequency pass through, and the second filter part 20b is configured so as to maximize the output from the subtracting part 20c regarding the input component of the same specific spatial frequency as this. Thus, such output characteristics that make a steep peak appear in the specific spatial frequency can be obtained by using a simple configuration.
CHIBA TAKUYA
YONEDA YUTAKA
