Disclosed is an image data compression method including determining whether image data can be compressed by a target compression ratio using one of at least one lossless compression scheme for compressing image data, when the image data can be compressed by the target compression ratio using the one of the at least one lossless compression scheme, encoding the image data using the one of the at least one lossless compression scheme, and when the image data cannot be compressed by the target compression ratio using the one of the at least one lossless compression scheme, encoding the image data by the target compression ratio using one of at least one lossy compression scheme.