1. A method for compressing image data, comprising: receiving the image data, wherein the image data comprises a first image of an object; creating a mapping between luminance and chrominance for the first image; 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 the compressed image data comprises luminance values for pixels of the first image and does not comprise chrominance values for pixels of the first image, and wherein said compressing uses the mapping; 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 first image is compressed according to the first compression method; and storing the compressed image data.