A luminance signal generation apparatus that generates a luminance signal for each pixel from an image signal read from an image sensor that includes a primary color Bayer pattern type of color filter array, the luminance signal generation apparatus comprising: a first signal (AC_1) generating means for generating a first high frequency signal from a first image signal that was generated by limiting a spatial frequency bandwidth of the image signal with use of image signals from all colors of pixels of the image sensor; a second signal (AC_2) generating means for generating a second high frequency signal from a second image signal that was generated by limiting the spatial frequency bandwidth of the image signal to a lower bandwidth than the first image signal with use of an image signal from one of a red or a blue pixel of the image sensor; a third signal (AC_3) generating means for generating a third high frequency signal from a third image signal that was generated by limiting the spatial frequency bandwidth of the image signal to a lower bandwidth than the first image signal with use of an image signal from a green pixel of the image sensor; a first computing means for computing, from the image signal read from the image sensor, a colour intensity measure for a pixel of interest, the measure indicating an intensity of a redness or blueness of the pixel of interest; a second computing means for computing, from the image signal read from the image sensor, an angle of a subject line for the pixel of interest; a luminance signal generating means (1032, 1033, 1040-1050) for generating a luminance signal (Yh) from the image signal for the pixel of interest; and adding means (1039, 1051, 1052) for generating an output luminance signal (Yh final) for the pixel of interest that was generated by adding the first signal (AC_1), the second signal (AC_2), the third signal (AC_3), and the luminance signal (Yh) in such a way that, based on the colour intensity measure and the angle of the subject line, the second signal is weighted proportionally to the intensity of the redness or blueness of the pixel of interest increases, and the third signal when the angle of the subject line indicates an oblique line is weighted inverse proportionally to the third signal when the angle of the imaging subject indicates a vertical or horizontal line. a first signal (AC_1) generating means for generating a first high frequency signal from a first image signal that was generated by limiting a spatial frequency bandwidth of the image signal with use of image signals from all colors of pixels of the image sensor; a second signal (AC_2) generating means for generating a second high frequency signal from a second image signal that was generated by limiting the spatial frequency bandwidth of the image signal to a lower bandwidth than the first image signal with use of an image signal from one of a red or a blue pixel of the image sensor; a third signal (AC_3) generating means for generating a third high frequency signal from a third image signal that was generated by limiting the spatial frequency bandwidth of the image signal to a lower bandwidth than the first image signal with use of an image signal from a green pixel of the image sensor; a first computing means for computing, from the image signal read from the image sensor, a colour intensity measure for a pixel of interest, the measure indicating an intensity of a redness or blueness of the pixel of interest; a second computing means for computing, from the image signal read from the image sensor, an angle of a subject line for the pixel of interest; a luminance signal generating means (1032, 1033, 1040-1050) for generating a luminance signal (Yh) from the image signal for the pixel of interest; and adding means (1039, 1051, 1052) for generating an output luminance signal (Yh final) for the pixel of interest that was generated by adding the first signal (AC_1), the second signal (AC_2), the third signal (AC_3), and the luminance signal (Yh) in such a way that, based on the colour intensity measure and the angle of the subject line, the second signal is weighted proportionally to the intensity of the redness or blueness of the pixel of interest increases, and the third signal when the angle of the subject line indicates an oblique line is weighted inverse proportionally to the third signal when the angle of the imaging subject indicates a vertical or horizontal line.