Digital media is becoming an ever more prevalent aspect of our lives. The uses for digital media include entertainment, financial, document management, security, marketing, medical, research, art, and personal use. Digital media includes:

Most people are familiar with using digital media for personal uses. Digital media is popularly used for:

Digital media is all around us. The proliferation of digital devices such as MP3 players, digital cameras, digital video recorders, video playback devices, and other devices is increasing. The amount of media available in digital form is also increasing. Today most media is created using digital devices, but also images, songs, and videos that were once available only in analog form, such as magnetic tape, photographs, and movie reels, are being digitized so that they can be archived, shared, and used by a larger number of people anywhere in the world.

Since the era of the World Wide Web (WWW) is upon us, digital media is being used more often than ever before—it is all around us. People save, share, buy, and use digital media every day. Digital images are nearly required to sell products over the Internet. Many people share their family pictures with online photo albums or put media on the Web to inform or entertain the general public.

Other equally important uses of digital media are used every day. Security is enhanced with the use of digital media. Images of missing people or criminal suspects can be sent around the world in a matter of seconds. Images from security cameras can be used to identify criminals. Media from a crime scene can be used to prosecute, defend, or solve a crime.

Digital satellite images are used to measure environmental impact, such as the shrinking of the rain forest. They can also be used for crop predictions and other kinds of research. Images from space are expanding our knowledge of the universe.

Medical information is now routinely digitized, including waveforms (such as audio), images, and video. This allows for recordkeeping, perhaps to judge the progression of a condition to enhance patient care. This digital media information can also be sent to specialists around the world to improve and expedite diagnoses.

Media related to news and current events are created and stored in digital form for broadcasting around the world and for archiving for future use.

Photographers are increasingly making their stock photography available on the Web. Stock photography can be used for advertising, editorial, and the entertainment industries, as well as for Internet use.

Financial institutions store images of important documents, such as checks for check clearing purposes and customer inspection.

Pattern images, such as those used for fabrics, wallpaper, and carpeting and other flooring are stored in image databases. Image content–based retrieval is particularly useful for searching these kinds of pattern images for color, texture, and shape from thousands of pattern images.

Entire collections of art, history, and archeology are being digitized and made available. This process makes this information available to anyone in the world. Because of this, we are more aware of our own history and culture, as well as the history and culture of others.

The challenge of this proliferation of digital media, in what it is used for and the amount and size of media, is how to make it available to the people who can, and should, use it. Making this media easily available includes the following challenges:

Perhaps the first and simplest digital media management solution is a set of files in an individual computer directory, which can be called directory managed media. This kind of storage and management needs the knowledge of the users to find and access the media. This kind of storage and access is, and will be, used to store digital media, even today, for small collections of media. This kind of storage depends on the individual users and computer operators to manage the data correctly, such as backing up the data. This kind of storage is typically used for temporary storage or work in progress.

This simple kind of storage was moved to networked computers so that the media could be stored or accessed by a number of users. In time these computers were increasingly managed by operators rather than individual users.

One obvious limitation of directory managed media is the limitation of information about the image, or image metadata, that is available. The only metadata available is the directory structure, the file name, and file date/ time. Other metadata might be available in the media itself, but it could not be used to locate the media.

Indexes were created to overcome the metadata limitations of directory managed media. These indexes help users find media. These indexes could include as much metadata as needed for the particular application the user has in mind. These indexes are stored in individual files and may include metadata information from the media itself. In fact, many popular desktop search engines, such as those supplied by Google, use media metadata to find media on a desktop. Indexed solutions allow for descriptions and keyword searches.

The separation of metadata indexes and actual media data continued for a long time. The metadata indexes moved from flat files (heap, hash, B+-tree, and so on) to databases. These media metadata indexes were eventually put into purpose-built databases such as indexed sequential access method (ISAM) databases and relational databases.

This kind of management had different storage for index and media. For example, the media might be stored on a laser disk farm and the index on a magnetic disk. Many times different tools were needed to manage the media and index. Digital media management applications were built. Sometimes these were custom applications and other times these were special-purpose media applications. These kinds of systems are binary systems, where index and content are separated.

Eventually, the management of digital media was achieved using a single database infrastructure. This infrastructure is a database where both the media metadata and content itself is stored and managed.

Having a single infrastructure for both digital media indexes and digital media content means having one set of management tools to deal with. In a binary system, the data must be managed separately. The media index as well as the content must be managed. For example, the content is backed up using one tool and the index is backed up separately.

Along with unifying management of the digital media database, the database has access to the set of features offered by the database. These database features include features for performance, security, integrity, and loss prevention of the data.

Performance features include many techniques to automatically distribute the physical input/output (I/O) load among a set of physical disks. This can be very important for a media database since the amount of data that is moved from disk to the application can be large. Database indexes are well suited to finding data quickly.

A database is also especially well suited to securing data. Access can be blocked to only the users who have the privilege to access the data. This can be either on the database as a whole or individual items of media within the database itself. For integrity of the data, transactions can be used so that there is not a mismatch between what is in the index and the content in the digital media database. The database also has a plethora of techniques for loss prevention of data, from mirroring data to backing up data to real-time transfer of database updates to a remote site.

Initially there was only one type of data that was stored in a database—the text type. Soon there were other types introduced, such as a number type and date type. These date and number types could be stored in the text type as well. However, by using different types for date and number types they can be better understood and better managed. For example, a number or a date could be converted to binary for efficient storage. Also, these types suggest operations that can be performed on them. For example, numbers can have arithmetic operations and dates can be output in different national standards.

The types also have the advantage that database tools and applications implicitly know how to deal with the data—how it can be represented, how it can be output, how it can be used, etc. For example, a simple image browsing application could be written to scan all the tables that belong to a user. Using the table metadata, the application can determine the tables that have an image stored in one of the columns because the table metadata indicates the column is an image type. The application can then use the image metadata stored in the image type to display the image (MIME type, width, height, etc.).

In initial unified media databases, image content was stored in simple binary large objects (BLOB) data types. These data types could be used to store any kind of data, including text, but were traditionally used for binary data items, such as every media type or large binary documents. The BLOB does not suggest what it holds and what metadata can be associated with it.

By using a type to store media data, applications can deal with the type automatically. For example, it is known that media has a MIME (multipurpose Internet mail extensions) type. The type gives a standard way to access this MIME type. Other metadata is also implicit, for example, there is a height and width for an image, so accessors are available in the type to allow access to this information as well.

As well as being able to implicitly understand what a database column holds, a media type also has operations that can be performed on that data type. For example, the image data type has methods to do things such as making a smaller version of the image (a thumbnail image). These media operations are close to the data so that the cost of data transfer from and to the database is minimized.

The infrastructure for handling Digital Media has evolved from storage in simple filesystems to being managed by databases. The database infrastructure has likewise evolved, increasing functionality especially for managing Digital Media. The database centralizes the management of digital media, and various other technologies are provided to access the media in the database. Any system designed to deal with Digital Media should strongly consider the advantages of managing the media within a database.