1. Field of the Invention
The present invention relates to an image composition technique for overlaying, on a part of an image serving as a background, another image serving as a foreground.
2. Description of the Related Art
For example, Jpn. Pat. Appln. KOKAI Publication No. 2000-209425 (hereinafter referred to as Patent Document 1) describes a conventional image composition technique used when, on a part of an image serving as a background (hereinafter referred to as a background image), another image serving as a foreground (hereinafter referred to as a foreground image) is overlaid to produce a new image. In this technique, the gradation and style of the foreground image are adjusted so as to reduce differences in gradation and style between the background image and the foreground image. Using the image composition technique described in Patent Document 1 provides a more natural composite image that prevents a viewer from feeling the image odd even if for example, images taken with a digital camera under different image taking conditions and recorded as image data are used as a background image and a foreground image.
However, the image composition technique described in Patent Document 1 cannot deal with the following case. For example, whereas the foreground image is an image taken with a camera, the background image is a pictorial image obtained by subjecting a camera-taken image to an image conversion process so that the image offers a pictorial style that is a visual characteristic similar to that of pictures of a particular type (Japanese painting, Western painting, or the like). That is, disadvantageously, a natural composite image cannot be obtained even when the gradation and style of the foreground image are adjusted in accordance with the gradation and style of the background image.
In view of the above-described circumstances, an image composition technique is desired to be presented by which a foreground image is overlaid on a part of a background image to form a more natural composite image that prevents the viewer from feeling the image odd even if one of the foreground image and the background image is a pictorial image.