1. A method for compressing image data, comprising: receiving the image data, wherein the image data comprises a first image of an object; dividing the first image into portions; for each portion, determining whether the portion includes a part of the object; compressing the image data based on said determining, wherein, if a compression condition is met, said compressing is performed according to a first compression scheme, wherein, in the first compression scheme: portions including a part of the object are compressed according to a first compression method; and portions not including a part of the object are discarded, wherein background information is stored for the portions not including a part of the object; wherein, if the compression condition is not met, said compressing is performed according to a second compression scheme, wherein, in the second compression scheme: each portion of the object is compressed according to the first compression method; and storing the compressed image data.