Vein imaging apparatus, positional displacement interpolation method, and program

A positional displacement interpolation method comprising the steps of;

• detecting a image focus position at imaging temperature based on data for detecting positional displacement obtained from a positional displacement detection data generation region of a vein imaging apparatus including:
• a lens array including a plurality of light-receiving lenses disposed in an array,
• a near-infrared light emission source which is arranged at an end of he lens array and emits a near-infrared light to a part of a living body, and
• an imaging element including a vein image data generation region for generating image data of a vein based on the near-infrared light that was condensed by the lens array and that was scattered in the living body and transmitted through the vein, and the positional displacement detection data generation region that includes a shielded section in which pixels are shielded from a light and an opening section in which pixels are not shielded from the light, and generates data for detecting a positional displacement that is used to detect, based on the light received via the opening section, variation in an image focus position according to an imaging temperature, wherein a plurality of pixels are assigned to one of the light-receiving lenses;
• estimating an amount of displacement of the image focus position at the imaging temperature based on the detected image focus position;
• and
• selecting, based on the amount of displacement, a pixel generating the vein image data used to generate vein image from among the plurality of pixels corresponding to one of the light-receiving lenses.

A non-transitory computer-readable medium storing instructions, which when executed by a processor causes a computer that controls a vein imaging apparatus to realize:

• an image focus position detection function for detecting a image focus position at imaging temperature based on data for detecting positional displacement obtained from a positional displacement detection data generation region;
• a positional displacement amount estimation function for estimating an amount of displacement of the image focus position at the imaging temperature based on the image focus position detected by the image focus position detection function;
• and
• a pixel selection function for selecting, based on the amount of displacement, a pixel for generating vein image data used to generate vein image from among a plurality of pixels corresponding to one of light-receiving lenses,
• wherein the vein imaging apparatus includes:
• a lens array including a plurality of light-receiving lenses disposed in an array,
• a near-infrared light emission source which is arranged at an end of the lens array and emits a near-infrared light to a part of a living body, and
• an imaging element including a vein image data generation region for generating image data of a vein based on the near-infrared light that was condensed by the lens array and that was scattered in the living body and transmitted through the vein, and the positional displacement detection data generation region that includes a shielded section in which pixels are shielded from a light and an opening section in which pixels are not shielded from the light, and generates data for detecting a positional displacement that is used to detect, based on the light received via the opening section, variation in an image focus position according to an imaging temperature, wherein a plurality of pixels are assigned to one of the light-receiving lenses.