According to the related art, various application services may be enabled by inserting additional data into an image file.
As example of the related art, the following two patents are discussed below: U.S. Pat. No. 6,993,196 “Digital image storage method” (hereinafter referred to as related art 1) and U.S. Pat. No. 8,340,440 “Apparatus and method for inserting additional data into image file in electronic device” (hereinafter referred to as related art 2).
In the specification, for convenience of explanation, an image file having additional data inserted therein is referred to as a compound file.
In such a way, once the compound file is created, various application services may be enabled when the image file is played. For example, when the additional data is sound source data, a sound collected while the corresponding image file is captured or a sound harmonizing with the image file may be provided while the image file is played. Alternatively, various pieces of information or information obtaining sites (for example, a Uniform Resource Locator (URL) link) relative to the image file may be provided.
On the other hand, in order to widely use a compound file, it becomes an important issue to rapidly determine whether a specific image file is a file having image data (e.g., an image file, a compound file having additional data, and the like) inserted therein. Furthermore, even when it is determined as a compound file, it may become an important issue to rapidly access additional data by a data processing device which processes the image file. In addition, wide usability of the compound file or compatibility between applications can be ensured by allowing the additional data to be easily inserted or removed.
However, the related art 1 discloses a method for confirming whether an image file is a compound file. For this, an End of Image (EOI) is compared with an End of File (EOF), and, when the EOF is larger than the EOI, (i.e., some data is further included behind image data), the image file is determined as the compound file. However, although the data processing device handling the image file can rapidly access the EOF, it takes a lot of time and work to determine the EOI. For example, according to a type of image file, there is a case where information for a location of the EOI exists in a header, but there is also a case where information for the location of the EOI does not exist in the header. In addition, although the header has the EOI information, a process is needed to search at least the header of the image file for information on the EOI. Accordingly, a lot of time and accesses are needed for determining whether the image file is a compound file, and accordingly a lot of time is to be taken to access the additional data by the data processing device.
Moreover, the related art 2 discloses that information for presence or absence of additional data is recorded in a header. This method is illustrated in FIG. 1.
FIG. 1 illustrates a schematic structure of a compound file according to the related art.
Referring to FIG. 1, a compound file 10 includes an image file and additional data 13 which is inserted into the image file. The image file includes a header 11 and image data 12. As illustrated in FIG. 1, the header 11 has important information recorded therein for handling the image file, such as a type of the image file, and information related to encoding and decoding. In addition, in the related art 2, the header 11 has information for presence of the additional data or a location of the additional data recorded therein. Accordingly, even in the related art 2, a long time may be taken to sequentially search the header 11 in order to confirm whether the image file is a compound file, that is, a longer time to be taken as a size of the header 11 becomes larger. Furthermore, when the presence of the additional data or an item related to the additional data is recorded in the header 11, there is a risk for losing information for the additional data when an event (e.g., re-encoding, resizing, changing of the image file, and the like) by which header information may be changed occurs, while the image file is handled by a data processing device. Moreover, in order to prevent this type of risk, the information on the additional data needs to be separately managed in occurrence of the event, which causes problems in wide usability or compatibility for various applications which handle corresponding compound files. In addition, there may also be a limitation of changing the header 11 when the additional data is further inserted or removed.
Therefore, a need exists for a compound file format, a compound file creating method, and a data storage device capable of rapidly confirming whether an image file is a compound file, rapidly accessing the additional data, and easily performing insertion or removal of the additional data.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.