Focus adjustment method and device using a determined reliability of a detected phase difference

A focus adjustment method, for an imaging device provided with an image sensor having imaging pixels that receive light of a subject image though a photographing lens and perform photoelectric conversion, and paired phase difference pixels that respectively receive light flux corresponding to pupil regions that are paired with the photographing lens and perform photoelectric conversion on the light flux that has been received, comprising:

• detecting a phase difference based on pixel data of the paired phase difference pixels;
• calculating pixel data of virtual image pixels at positions of the phase difference pixels, or selecting pixel data of image pixels around positions of the phase difference pixels;
• calculating degree of coincidence between each pixel data of the virtual image pixels that have been calculated, or calculating degree of coincidence of each pixel data of image pixels that have been selected for positions of paired phase difference pixels;
• determining reliability of the phase difference detection result in accordance with the degree of coincidence;
• performing focus adjustment based on the phase difference detection result and the reliability;
• and
• at the time of the pixel data calculation,
• setting gain for pixel data of the phase difference pixels;
• interpolating pixel data of virtual imaging pixels corresponding to position of the phase difference pixels, based on pixel data of imaging pixels positioned around the phase difference pixels;
• and
• calculating pixel data of virtual imaging pixels corresponding to positions of the phase difference pixels based on a value resulting from having applied the gain to pixel data of the phase difference pixels, and the pixel data that has been interpolated.

A non-transitory computer-readable medium, storing a processor executable code, which when executed by at least one processor, the processor being provided within an imaging device provided with an image sensor having imaging pixels that receive light of a subject image though a photographing lens and perform photoelectric conversion, and paired phase difference pixels that respectively receive light flux corresponding to pupil regions that are paired with the photographing lens and perform photoelectric conversion on the light flux that has been received, performs a focus adjusting method, the focus adjusting method comprising:

• detecting a phase difference based on pixel data of the paired phase difference pixels;
• calculating pixel data of virtual image pixels at positions of the phase difference pixels, or selecting pixel data of image pixels around positions of the phase difference pixels;
• calculating degree of coincidence between each pixel data of the virtual image pixels that have been calculated, or calculating degree of coincidence of each pixel data of image pixels that have been selected for positions of paired phase difference pixels;
• determining reliability of the phase difference detection result in accordance with the degree of coincidence;
• performing focus adjustment based on the phase difference detection result and the reliability;
• and
• at the time of the pixel data calculation,
• setting gain for pixel data of the phase difference pixels;
• interpolating pixel data of virtual imaging pixels corresponding to position of the phase difference pixels, based on pixel data of imaging pixels positioned around the phase difference pixels;
• and
• calculating pixel data of virtual imaging pixels corresponding to positions of the phase difference pixels based on a value resulting from having applied the gain to pixel data of the phase difference pixels, and the pixel data that has been interpolated.