A control device according to an embodiment of the present technology includes an acquisition section, a block control section, and a calculator. The acquisition section acquires an image signal of a tissue of a living body irradiated with laser light and on which image-capturing has been performed. The block control section controls a size of a pixel block according to an image-capturing condition for the image-capturing on the tissue of a living body. The calculator calculates speckle data based on the acquired image signal, using the pixel block of which the size is controlled.
