1. A method of object detectable and background removal for enabling an object to be automatically detected minutely and accurately as far as contours comprising the steps of: using an image consisting of a background and an object of detection target as an input image, by way of an input process of said image; selecting a sectional image including only said background, while dividing said input image into said sectional images, by way of a background only sectional image selection process; estimating a background on said input image based on a sectional image including said background, by way of a background estimation process; and comparing said estimated background with said input image by way of a comparison process, wherein said method causes said object of detection target to be isolated from said input image.