A method of imaging using optical coherence tomography, OCT, comprising: acquiring a first three dimensional data set by applying an OCT scan targeting a first three dimensional region of a sample; creating a first two dimensional map based on representative intensity values respectively of a plurality of pieces of A-scan data included in the first three dimensional data set on which an imaging process has not been performed; designating a second three dimensional region of the sample based on the first two dimensional map; acquiring a second three dimensional data set by applying an OCT scan targeting the second three dimensional region ; and generating image data from at least part of the second three dimensional data set, wherein the generating the image data includes: creating a second two dimensional map based on representative intensity values respectively of a plurality of pieces of A-scan data included in the second three dimensional data set on which an imaging process has not been performed, designating a partial data set of the second three dimensional data set by a comparison between the first two dimensional map and the second two dimensional map; and generating the image data from the partial data set, and wherein the designating the second three dimensional region includes: based on the first two dimensional map, designating a target region that is a three dimensional region included in the first three dimensional region; and designating the second three dimensional region to include the target region. acquiring a first three dimensional data set by applying an OCT scan targeting a first three dimensional region of a sample; creating a first two dimensional map based on representative intensity values respectively of a plurality of pieces of A-scan data included in the first three dimensional data set on which an imaging process has not been performed; designating a second three dimensional region of the sample based on the first two dimensional map; acquiring a second three dimensional data set by applying an OCT scan targeting the second three dimensional region ; and generating image data from at least part of the second three dimensional data set, wherein the generating the image data includes: creating a second two dimensional map based on representative intensity values respectively of a plurality of pieces of A-scan data included in the second three dimensional data set on which an imaging process has not been performed, designating a partial data set of the second three dimensional data set by a comparison between the first two dimensional map and the second two dimensional map; and generating the image data from the partial data set, and creating a second two dimensional map based on representative intensity values respectively of a plurality of pieces of A-scan data included in the second three dimensional data set on which an imaging process has not been performed, designating a partial data set of the second three dimensional data set by a comparison between the first two dimensional map and the second two dimensional map; and generating the image data from the partial data set, and wherein the designating the second three dimensional region includes: based on the first two dimensional map, designating a target region that is a three dimensional region included in the first three dimensional region; and designating the second three dimensional region to include the target region. based on the first two dimensional map, designating a target region that is a three dimensional region included in the first three dimensional region; and designating the second three dimensional region to include the target region. <EOS>