An image signal processing apparatus and method for processing an image signal input from an analog-to-digital converter (ADC) in a pixel-by-pixel basis and generating a bright signal corresponding to chrominance signals comprise a low pass filter (LPF), an subtractor, an adder, and a bright signal controller. The LPF cancels a high frequency component of the chrominance signals contained in the input image signal. The subtractor generates a high frequency component signal by subtracting an output signal of the LPF from the input image signal. The adder generates the bright signal by adding the high frequency component signal generated by the subtractor to the output signal of the LPF. The bright signal controller increases the high frequency component signal generated by the subtractor if a pixel position of the input image signal is within an object range, and decreases the high frequency component signal generated by the subtractor if a pixel position of the input image signal is out of the object range.