The present invention relates to a method and apparatus for synthesizing a plurality of data that is in compressed format. According to one aspect of the present invention, there is provided a method of creating a synthesized data by synthesizing a plurality of source data that is in compressed format, the method including the steps of: extracting a portion of one of the plurality of source data; decompressing the extracted portion to create a decompressed data portion; and synthesizing two or more of the decompressed data portions derived from different ones of the source data to create a part of the synthesized data. The extracting, decompressing and synthesizing step will be repeated until the creation of the synthesized data is completed.