1) Field of the Invention
The present invention relates to an image processing apparatus and an image processing method that create a plane image from binocular stereoscopic image data including plane image data for right and left eyes viewed from a viewpoint set arbitrarily.
2) Description of the Related Art
Conventionally, one of three-dimensional image display methods for enabling binocular stereoscopic vision separates images for left and right eyes including images viewed from different viewpoints for right and left eyes of a viewer, and gives binocular parallax to the viewer so as to enable stereoscopic viewing. As a method of creating a plane image from an arbitrary viewpoint based on such images, Japanese Patent Application Laid-open No. 2002-324249 and Japanese Patent Application Laid-open No. 2002-56407 discloses a method of creating a plane image that can be seen naturally in geometry at that time of viewing an image.
FIG. 5 is a block diagram of a main part of a conventional image processing apparatus. The conventional image processing apparatus includes an image input unit 1, a plane-image creating unit 2, and an image output unit 5. The image input unit 1 receives, for example, binocular stereoscopic image data including plane image data for right and left eyes from an arbitrary set viewpoint as an input. The plane-image creating unit 2 converts all the input binocular stereoscopic image data into plane image data by an image processing method as a conventional technique so as to output them. In the conventional image processing apparatus, therefore, the plane image data created by the plane-image creating unit 2 are not corrected at all.
When the plane image is created from the binocular stereoscopic image, however, if a photographing condition of a binocular stereoscopic image input device at the time of photographing is not right, for example, exposure is insufficient or white balance is not right. In this case, there occurs an unnatural image.
Since an image of close view includes many comparatively high spatial frequency components, many operations are required for making the image quality of close view high. A speed of the operations is, therefore, reduced, and the apparatus becomes larger. Since an image of distant view includes many comparatively low spatial frequency components, such a process is not necessary.
When an image such that a person in front of a flesh-colored wall, for example, is displayed or output by an image display device such as a monitor or an image forming device such as a printer, if the background and the person are subject to the same image process, the color of the person's skin turns to be different from a color conceived by people as ideas. As a result, the output image may be felt unnatural.
The plane images created by the methods disclosed in the Japanese Patent Application Laid-open No. 2002-324249 and Japanese Patent Application Laid-open No. 2002-56407 are reproduced only as a plane image from a specified a single viewpoint in space, without disclosing any correcting unit for such an unnatural plane image.