1. An image processing apparatus comprising: an image source acquiring unit that acquires an image source; a determining unit that determines whether the image source acquired by the image source acquiring unit is a moving image source or a still image source; a setting unit that sets a size of a matrix of a smoothing range used in a noise eliminating process of a color difference plane to be larger than a size of a matrix of a smoothing range used in a noise eliminating process of a luminance plane if the determining unit determines that the image source is the moving image source and sets the size of the matrix of the smoothing range used in the noise eliminating process of the luminance plane to be larger than the size of the matrix of the smoothing range used in the noise eliminating process of the color difference plane if the determining unit determines that the image source is the still image source; and a noise eliminating process executing unit that executes the noise eliminating process of the luminance plane and the noise eliminating process of the color difference plane on image data from the image source acquired by the image source acquiring unit, using the size of the matrix of the smoothing range set by the setting unit.