To improve a processing speed, and to clarify the outline of a picture in a picture processing based on a stereo method.

The pictures of a screen 2 and an object 3 image picked-up by a stereo image pickup device 5 are converted into key signals in which the value of a picture element belonging to an area corresponding to the object 3 is 1 and the value of a picture element belonging to the other areas is 0 by a chroma key processing part 6(6-1-6-4, and 6b), and the picture of an area corresponding to the object 3 is extracted from the original picture. A stereo distance calculating part 7 uses a picture outputted from the chroma key processing part 6b as a reference, and executes a processing based on a stereo method between the picture and pictures outputted from the chroma key processing parts 6-1-6-4 for generating a distance picture in which a distance to each point on the surface of the object 3 is made correspond to each picture element of the picture. That is, the stereo distance calculating part 7 detects a parallax at first, and then calculates distance information based on the parallax, and outputs an obtained result as a digital distance signal DV1.