4. An image forming method performed in an image forming device, comprising: receiving a duplicate electronic document including vector data and metadata generated in another image forming device, wherein the vector data is generated from a first resolution-dependent display list which is not included in the duplicate electronic document; in the case of a first printing, generating a second resolution-dependent display list from the vector data of the duplicated electronic document; in the case that a second printing is performed which is higher quality than that of the first printing, and a resolution of an original electronic document which is a copy source of the duplicate electronic document and a resolution in the second printing are in the same range as a result of comparing the resolutions, obtaining the first resolution-dependent display list having been used in creation of the vector data from information included in the metadata, wherein the information indicates the location of the original electronic document which is the copy source of the duplicate electronic document; and printing by using the second resolution-dependent display list generated from the vector data, or using the first resolution-dependent display list obtained from the information which indicates the location of the original electronic document.
5. The image forming method according to claim 4 , wherein the original electronic document being a copy source of the duplicate electronic document includes at least a resolution-dependent display list, vector data generated by vectoring drawing data included in the original electronic document, and metadata, and wherein the copy source is stored in an image forming device connected via a network.