A signal processing circuit is utilized in a video camera which includes a CCD having pixels arranged in a dot-matrix fashion and color filters of R, G and B arranged in a mosaic fashion, and an output signal from the CCD is converted into a digital signal. A horizontal aperture signal (Hap) and a vertical aperture signal (Vap), which are produced on the basis of the digital signal, are multiplied by coefficients (K1, K2) which are obtained on the basis of a horizontal correlation value (Sh) and a vertical correlation value (Sv), and then, added to each other in an adding circuit, whereby an aperture signal is obtained by the adding circuit. The aperture signal is added to a luminance signal to perform an image enhancement.