1. An image processing apparatus comprising: an image sensor that has an RGBW array including an RGB pixel which is a light receiving element corresponding to wavelength light of each RGB color and a W pixel which is a light receiving element receiving substantially all RGB wavelength light; and an image processing unit that performs image processing by inputting a sensor image formed of an RGBW pixel signal output from the image sensor, wherein the image sensor has a periodic array of a unit composition formed of each RGBW pixel, and has an array in which composition ratios of each RGB pixel within the unit composition are adapted to be the same as each other, and wherein the image processing unit converts a pixel array of the sensor image formed of the RGBW pixel signal, and performs at least either array conversion processing for generating an RGB array image or signal processing for generating each RGB image signal in which all RGB pixel values are set for each pixel position of the sensor image.