1. An image processing device, comprising: an image acquiring unit configured to acquire an image containing pixels; a picture searching unit configured to search for a picture region in the image; a background acquiring unit configured to perform a background connected region acquiring operation on a non-picture region of the image in which the picture region is not included and the picture region, and to obtain a non-picture background connected region and a picture background connected region, respectively, wherein each of the pixels in the non-picture background connected region is defined as a non-picture background pixel, and each of the pixels in the picture background connected region is defined as a picture background pixel; a foreground acquiring unit configured to remove the non-picture background connected region and the picture background connected region from the non-picture region and the picture region respectively, and to obtain a non-picture foreground region of the non-picture region and a picture foreground region of the picture region respectively, wherein each of the pixels in the non-picture foreground region is defined as a non-picture foreground pixel, and each of the pixels in the picture foreground region is defined as a picture foreground pixel; and a merging unit configured to merge the non-picture foreground region of the non-picture region and the picture foreground region of the picture region to obtain an ultimate image foreground region, wherein each of the pixels in the image foreground region is defined as an image foreground pixel.