Image capturing apparatus, control method of the same and image sensor

An image capturing apparatus, comprises: an image capturing unit configured to generate image data of an object; an adding unit configured to add additional information, including first region information for specifying a first pixel region of the image data, and second region information for specifying a second pixel region included in the first pixel region, to the image data; a transmission unit configured to transmit the image data to which the additional information is added; and an image processing unit configured to extract from the image data, which is received via the transmission unit, the first pixel region and the second pixel region specified by the additional information obtained by receiving the image data, and to perform predetermined image processing on the extracted first pixel region and second pixel region.