Image combining apparatus, image combining method and program product

An image combining apparatus comprising:

• a selecting unit configured to select at least overexposure image data and underexposure image data based on correct exposure image data from a plurality of first image data which are separated from each of a plurality of image data captured in different exposures, each of the plurality of first image data being composed of luminance components specified in a certain color space;
• a generating unit configured to generate smoothed image data by averaging the selected plurality of first image data selected by the selecting unit so as to smooth the selected plurality of first image data;
• a first combining unit configured to combine data of each pixel located in the same position of the separated plurality of first image data, by using certain combining rates which are different according to coordinates and which are based on a luminance value of the generated image data generated by the generating unit;
• and
• a second combining unit configured to combine data of each pixel of a plurality of second image data which correspond to the selected first image data selected by the selecting unit and which pixel data is located in the same position as in the first image data, by using the certain combining rates which are the same combining rates used in the first combining unit and which are used at the same positions as in the first image data, each of the plurality of second image data which being separated from each of the plurality of image data captured in different exposures and being composed of components other than luminance components specified in a certain color space.