1. A panoramic image producing apparatus comprising: a processing device to control an overall operation for producing a panoramic image based on an input image; an imaging device operatively connected to the processing device to acquire photographic images and to provide an acquired image to the processing device; a display device operatively connected to the processing device to display images including the panoramic image; a memory device operatively connected to the processing device and the imaging device to store data used for producing the panoramic image; the processing device is configured to conduct the following operations of: producing an intensity image of an input image captured by the imaging device; causing the memory device to store a reference image which is used as a reference when motion of the intensity image is calculated and absolute motion data of the reference image which represents motion of the reference image from a reference position; registering the intensity image of the target image and its motion data when a displacement value between a previously registered intensity image and the target image exceeds a certain predetermined value; performing a motion data calculation process for setting an intensity image of a newly input image as a target image, calculating relative motion data with multi-degrees of freedom of the target image with respect to the reference image according to a block matching process, and calculating the absolute motion data with multi-degrees of freedom of the target image from the reference position using the absolute motion data of the reference image and the relative motion data of the target image; producing a panoramic image that extends in 2- dimensional directions by performing a stitching process that stitches each input image corrected for distortion using its absolute motion data; and setting the target image as the new reference image based on a specific condition; performing a filtering process to produce image data of various resolutions; and in the motion data calculation process, calculating the relative motion data of the target image by performing a whole-image matching process that determines a parallel movement between the reference image and the target image of the lowest resolution, and calculating the relative motion data with multi-degrees of freedom of the target image with respect to the reference image by performing the block matching process to higher resolution intensity image using the motion data of the previous level of resolution as the initial value; wherein the processing device extracts one or more intensity images out of intensity images that are registered depending on an amount of overlap with the target image in a perpendicular direction against a motion direction of the target image, and calculates the relative motion data of the target image using the reference image and the intensity images extracted.