Image processing apparatus, imaging apparatus, and image processing method

An imaging apparatus comprising:

• an imaging portion generating an mage signal by performing photo-electric conversion of object light;
• a first interpolating portion calculating a first interpolation value using a pixel value of a particular pixel of interest in the image signal obtained by the imaging portion and pixel values of a plurality of pixels neighboring the pixel of interest;
• a second interpolating portion detecting the direction of a smallest jump amount among directions defined by the pixel of interest and the plurality of neighboring pixels to calculate a second interpolation value for the pixel value of the pixel of interest using the pixel values of pixels located in the direction of a smallest jump amount and the pixel value of the pixel of interest, the direction of a smallest jump amount being a direction in which a smallest sum of differences from the pixel values of the pixel of interest exists;
• a detecting portion determining, using the pixel values of the pixels located in the direction of the smallest jump amount, the first interpolation value and the second interpolation value, whether any change is made by interpolation performed using the first interpolation value in the relationship between the magnitudes of the pixel values of the pixel of interest and the pixels located in the direction of the smallest jump amount, selecting the first interpolation value when there is no change, and selecting the second interpolation value when there is a change;
• and
• an isolated point detecting portion determining whether the pixel of interest is an isolated point, outputting the first interpolation value or the second interpolation value selected by the detecting portion when it is determined that the pixel of interest is an isolated point, and outputting the pixel value of the pixel of interest when it is determined that the pixel of interest is not an isolated point.

An image processing method comprising the steps of:

• calculating a first interpolation value for a pixel value of a pixel of interest using pixel values of the pixel of interest and a plurality of pixels neighboring the pixel of interest;
• detecting the direction of a smallest jump amount among directions defined by the pixel of interest and the plurality of neighboring pixels to calculate a second interpolation value for the pixel value of the pixel of interest using the pixel values of pixels located in the direction of a smallest jump amount and the pixel value of the pixel of interest, the direction of a smallest jump amount being a direction in which a smallest sum of differences from the pixel values of the pixel of interest exists;
• determining, using the pixel values of the pixels located in the direction of the smallest jump amount, the first interpolation value and the second interpolation value, whether any change is made by interpolation performed using the first interpolation value in the relationship between the magnitudes of the pixel values of the pixel of interest and the pixels located in the direction of the smallest jump amount, selecting the first interpolation value when there is no change, and selecting the second interpolation value when there is a change;
• and
• determining whether the pixel of interest is an isolated point, outputting the first interpolation value or the second interpolation value selected by the detecting portion when it is determined that the pixel of interest is an isolated point, and outputting the pixel value of the pixel of interest when it is determined that the pixel of interest is not an isolated point.