1. A displaying and imaging apparatus comprising: a displaying and imaging panel having an image displaying function and an image capturing function; a generating unit for generating a difference image between a reflection light using image and a shadow image, the reflection light using image being obtained by imaging of an adjacent object by the displaying and imaging panel using reflection light of irradiation light emitted from the displaying and imaging panel, and the shadow image being obtained by imaging shadow of the adjacent object by the displaying and imaging panel; and an image processing unit for obtaining information of at least one of position, shape, and size of the adjacent object on the basis of the difference image, and the generating unit generates, on the basis of a plurality of images obtained at timings different from each other along time base, which are one of the reflection light using image or the shadow image, one interpolation image corresponding to the one of images obtained at a timing different from those of the plurality of images, and generates the difference image by the difference between the interpolation image and the other one of the reflection light using image and the shadow image.