An image processing device comprising: a storage section configured to store a plurality of low-resolution frame images when an image of an object is sampled while sequentially shifting a pixel so that overlap occurs, an imaging operation is performed by an image sensor while sequentially shifting the pixel, and a light-receiving value of the pixel obtained by each imaging operation is acquired as the low-resolution frame image; an estimation calculation section configured to estimate estimated pixel values at a pixel pitch smaller than a pixel pitch of the low-resolution frame image based on the plurality of the low-resolution frame images stored in the storage section; and an image output section configured to output a high-resolution frame image that has a resolution higher than that of the plurality of low-resolution frame images, characterized in that the pixel being shifted to be sequentially set at a first position and a second position subsequent to the first position so that the pixel set at the first position and the pixel set at the second position overlap each other, the estimation calculation section is configured to calculate a difference between the light-receiving value of the pixel set at the first position and the light-receiving value of the pixel set at the second position, and estimate the estimated pixel values based on the difference, and the image output section is configured to output the high-resolution frame image that has a resolution higher than that of the plurality of low-resolution frame images based on the estimated pixel values estimated by the estimation calculation section. a storage section configured to store a plurality of low-resolution frame images when an image of an object is sampled while sequentially shifting a pixel so that overlap occurs, an imaging operation is performed by an image sensor while sequentially shifting the pixel, and a light-receiving value of the pixel obtained by each imaging operation is acquired as the low-resolution frame image; an estimation calculation section configured to estimate estimated pixel values at a pixel pitch smaller than a pixel pitch of the low-resolution frame image based on the plurality of the low-resolution frame images stored in the storage section; and an image output section configured to output a high-resolution frame image that has a resolution higher than that of the plurality of low-resolution frame images, characterized in that the pixel being shifted to be sequentially set at a first position and a second position subsequent to the first position so that the pixel set at the first position and the pixel set at the second position overlap each other, the estimation calculation section is configured to calculate a difference between the light-receiving value of the pixel set at the first position and the light-receiving value of the pixel set at the second position, and estimate the estimated pixel values based on the difference, and the image output section is configured to output the high-resolution frame image that has a resolution higher than that of the plurality of low-resolution frame images based on the estimated pixel values estimated by the estimation calculation section.