Abstract: A focus depth extension image forming optical system includes a focus depth extension element that extends a depth of focus of an image forming optical system. The focus depth extension element added to the image forming optical system has an aspheric surface shape rotationally symmetric about an optical axis of the image forming optical system, a sag amount Z of the aspheric surface shape changes at least to be negative, positive, and negative or positive, negative, and positive in accordance with an increase in a distance from the optical axis, in a range of 0<|t|<0.4 where |t| is a normalized radius of the aspheric surface shape, a maximum value of |dZ/dt| is 0.4 or more, and in one or more point of a range of 0.4?|t|<0.8, dZ/dt=0.

Abstract: A focus depth extension image forming optical system includes a focus depth extension element that extends a depth of focus of an image forming optical system. The focus depth extension element added to the image forming optical system has an aspheric surface shape rotationally symmetric about an optical axis of the image forming optical system, a sag amount Z of the aspheric surface shape changes at least to be negative, positive, and negative or positive, negative, and positive in accordance with an increase in a distance from the optical axis, in a range of 0<|t|<0.4 where |t| is a normalized radius of the aspheric surface shape, a maximum value of |dZ/dt| is 0.4 or more, and in one or more point of a range of 0.4?|t|<0.8, dZ/dt=0.

Abstract: A stereo camera device detecting a distance to a subject includes two cameras and a calculation unit that calculates a distance to the subject based on the images acquired by the two cameras. The calculation unit includes an image processing unit that searches for corresponding points of the images acquired by the two cameras and calculates two parallaxes based on differences in positional coordinates of the corresponding points on the images, an offset value calculation unit that calculates parallax offset values across the images based on the two parallaxes calculated by the image processing unit at least at two time points, and a statistical processing unit that performs a statistical analysis on a distribution of the parallax offset values and determines an optimum value of the parallax offset values, the optimum value being used as a correction parameter.

Abstract: A stereo camera device detecting a distance to a subject includes two cameras and a calculation unit that calculates a distance to the subject based on the images acquired by the two cameras. The calculation unit includes an image processing unit that searches for corresponding points of the images acquired by the two cameras and calculates two parallaxes based on differences in positional coordinates of the corresponding points on the images, an offset value calculation unit that calculates parallax offset values across the images based on the two parallaxes calculated by the image processing unit at least at two time points, and a statistical processing unit that performs a statistical analysis on a distribution of the parallax offset values and determines an optimum value of the parallax offset values, the optimum value being used as a correction parameter.