Provided is an image inputting apparatus wherein luminance signals having a high S/N ratio can be generated even during nighttime with a small quantity of photons. An imaging element images image components. A color signal generating section generates color signals from the image components. A color space conversion section converts the color signals into a color space that includes luminance signals and color difference signals. The color space conversion section calculates a luminance signal obtained by adding the image components, as the luminance signal of the color space to be converted.