An image signal processing apparatus including a first tone correcting section for generating a first image signal by performing a space-variant tone conversion process for a digitalized image signal from a CCD and an A/D converting section, a second tone correcting section for generating a second image signal by performing a space-invariant tone correction process for the digitalized image signal from the CCD and the A/D converting section, and a synthesizing section for setting a synthesis rate R1 of the first image signal and a synthesis rate R2 of the second image signal, and synthesizing the first image signal and the second image signal based on the set synthesis rates R1 and R2.