1. Field of the Invention
The present invention relates to an image pickup apparatus represented by a digital camera and, more particularly, to a recording apparatus of an image, which is photographed by an image pickup apparatus having a refocus function and a reproducing apparatus of the recorded image.
2. Description of the Related Art
In recent years, an image pickup apparatus arranged such that a microlens array including microlenses arranged at one to a plurality of pixels is arranged in front of an image pickup element so that information of incidence directions of rays of light incident on the image pickup element can be obtained in addition to pixel signals has been proposed by a non-patent literature (Ren. Ng and seven others, “Light Field Photography with a Hand-Held Planoptic Camera”, Stanford Tech Report CTSR 2005-02) and the like. By using such image pickup apparatus, not only a normal photographed image based on output signals from respective pixels can be generated but also an image which is focused at an arbitrary focal length can be reconstructed by predetermined image processing is applied to a photographed image.
When such image that can be refocused is displayed for the purpose of browsing, it is difficult to judge at which a focus position an image to be displayed first is to be refocused. In order to solve this problem, a patent literature (Japanese Patent Application Laid-Open No. 2011-22796) extracts an object from an image, and displays a refocus image in which an area including that object is focused. Alternatively, image pickup conditions at the time of image are appended as tag data to image data, and a refocus image is generated based on that tag information.
However, the related art disclosed in the above patent literature requires processing for extracting an object before an image is displayed. Even in a case where information at the time of photographing is included as tag data, a phase difference between a plurality of images of different view points has to be calculated so as to determine a refocus plane after reconstruction, thus unwantedly generating arithmetic cost in either case.