Imaging apparatus and method for controlling imaging apparatus
Light transmitted through the imaging lens 100 is divided into two light fluxes by the half mirror 202 fixed in the camera body 200 , and two light fluxes are guided to the imaging element 201 and optical viewfinder, respectively. An image processing unit corrects aberration, which occurs due to the transmittance of light through the half mirror 202 , of the image data generated after receiving light at the imaging element 201 , by conversion processing based on a transfer function representing its optical transfer characteristics and restores the image data prior to the occurrence of aberration.
1. An imaging apparatus comprising:
an optical element that is obliquely disposed relative to the optical axis of an imaging lens in order to reflect and transmit a part of the light transmitted through the imaging lens;
an optical viewfinder that is capable of observing a subject with light reflected from the optical element;
an imaging element that receives light transmitted through the optical element to output image data; and
an image processing unit configured to correct aberration, which occurs due to the transmittance of light through the optical element, of the image data obtained by the imaging element, by conversion processing based on a transfer function according to the optical element and restore image prior to the occurrence of aberration,
wherein the image processing unit corrects aberration having a symmetry in a first axial direction based on a transfer function according to the optical element, and aberration having an asymmetry in a axial second direction that is perpendicular to the first axial direction and an optical axis of the optical element and is a travelling direction of the light reflected by the optical element based on the transfer function according to the optical element, wherein a value inverted from left to right is employed for a transfer function value at a position symmetrical to the first axial direction.
2. The imaging apparatus according to claim 1 , wherein the optical element is fixedly disposed between the imaging lens and the imaging element.
3. The imaging apparatus according to claim 1 , wherein the imaging lens is removably attached to the imaging apparatus, a part of the imaging lens is positioned closer to the imaging element side than one end portion of the optical element with the imaging lens mounted on the imaging apparatus, and the imaging lens and the optical element are partially overlapped when viewed from a direction perpendicular to the optical axis.
4. The imaging apparatus according to claim 1 , wherein the image processing unit corrects aberration, which occurs by the transmittance of light through the imaging lens and the optical element, of the image data obtained by the imaging element, by conversion processing based on a transfer function according to the imaging lens and the optical element, and restores the image.
5. The imaging apparatus according to claim 4 , wherein the image processing unit changes its transfer function depending on the imaging lens mounted on the imaging apparatus to correct the aberration.
6. A method for controlling an imaging apparatus, in which a part of the light transmitted through an imaging lens is reflected from an optical element to reach an optical viewfinder, and light transmitted through the optical element is received by an imaging element to output image data, the method comprising the steps of:
acquiring property information of an imaging apparatus including the optical element;
defining a transfer function according to the optical element that is obliquely disposed relative to the optical axis of an imaging lens based on the property information; and
correcting aberration, which occurs due to the transmittance of light through the optical element, of the image data obtained by the imaging element, by conversion processing based on the transfer function, and restoring/recovering image prior to the occurrence of aberration,
wherein in the correcting step, aberration having a symmetry in a first axial direction is corrected based on a transfer function according to the optical element, and aberration having an asymmetry in a second axial direction that is perpendicular to the first axial direction and an optical axis of the optical element and an optical axis of the optical element and is a travelling direction of the light reflected by the optical element is corrected based on the transfer function according to the optical element, wherein a value inverted from left to right is employed for a transfer function value at a position symmetrical to the first axial direction.