A method of imaging using optical coherence tomography, OCT, the method comprising: acquiring a plurality of three dimensional data sets from a plurality of three dimensional regions of a sample different from each other; generating a plurality of pieces of image data from the plurality of three dimensional data sets; performing a first registration between the plurality of pieces of image data by applying an image correlation calculation to each of a plurality of overlap regions in the plurality of pieces of image data; and composing the plurality of pieces of image data based on a result of the first registration; the method further comprising: designating an imaging region in the sample; and setting a plurality of target regions to include the imaging region, wherein the plurality of three dimensional data sets is acquired by sequentially applying an OCT scan to the plurality of target regions; the method including: acquiring two three dimensional data sets of said plurality of three dimensional data sets by sequentially applying OCT scans to two target regions of the plurality of target regions; generating two pieces of image data of said plurality of pieces of image data from the two three dimensional data sets; characterised by evaluating an overlap region of the two pieces of image data; and selecting, depending on the result of the evaluation, and performing one of: - applying the first registration to at least the two pieces of image data, and - applying another OCT scan to at least one of the two target regions; wherein said steps of acquiring two three dimensional data sets, generating two pieces of image data, evaluating an overlap region and applying the first registration or applying another OCT scan to at least one of the two target regions, are repeated until all of the plurality of pieces of image data are generated. acquiring a plurality of three dimensional data sets from a plurality of three dimensional regions of a sample different from each other; generating a plurality of pieces of image data from the plurality of three dimensional data sets; performing a first registration between the plurality of pieces of image data by applying an image correlation calculation to each of a plurality of overlap regions in the plurality of pieces of image data; and composing the plurality of pieces of image data based on a result of the first registration; the method further comprising: designating an imaging region in the sample; and setting a plurality of target regions to include the imaging region, wherein the plurality of three dimensional data sets is acquired by sequentially applying an OCT scan to the plurality of target regions; designating an imaging region in the sample; and setting a plurality of target regions to include the imaging region, wherein the plurality of three dimensional data sets is acquired by sequentially applying an OCT scan to the plurality of target regions; the method including: acquiring two three dimensional data sets of said plurality of three dimensional data sets by sequentially applying OCT scans to two target regions of the plurality of target regions; generating two pieces of image data of said plurality of pieces of image data from the two three dimensional data sets; characterised by evaluating an overlap region of the two pieces of image data; and selecting, depending on the result of the evaluation, and performing one of: - applying the first registration to at least the two pieces of image data, and - applying another OCT scan to at least one of the two target regions; wherein said steps of acquiring two three dimensional data sets, generating two pieces of image data, evaluating an overlap region and applying the first registration or applying another OCT scan to at least one of the two target regions, are repeated until all of the plurality of pieces of image data are generated. acquiring two three dimensional data sets of said plurality of three dimensional data sets by sequentially applying OCT scans to two target regions of the plurality of target regions; generating two pieces of image data of said plurality of pieces of image data from the two three dimensional data sets; characterised by evaluating an overlap region of the two pieces of image data; and selecting, depending on the result of the evaluation, and performing one of: - applying the first registration to at least the two pieces of image data, and - applying another OCT scan to at least one of the two target regions; - applying the first registration to at least the two pieces of image data, and - applying another OCT scan to at least one of the two target regions; wherein said steps of acquiring two three dimensional data sets, generating two pieces of image data, evaluating an overlap region and applying the first registration or applying another OCT scan to at least one of the two target regions, are repeated until all of the plurality of pieces of image data are generated.