Metadata are generally defined as “data about data.” Specifically, image metadata is basically essential information regarding a certain image or picture. Image metadata is classified into two types or categories, which are technical and content information.
Technical information simply pertains to the technical details of the image. Evidently, these image attributes are produced by one’s camera with every picture taken. Examples of an image’s technical information include ISO speed, camera type, and apperture value.
Content information, on the other hand, refers to the information or details about the image. This type of information commonly includes subject, keywords, category, country, and more others. While technical information is produced by a device or equipment used in creating the image, content information is instead created by an individual. Apparently, content is created through an individual’s understanding and perception of an image, thus providing description of image content.
Tagged Image File Format (TIFF), Joint Photographic Experts Group (JPEG), and Exchangeable image file format (EXIF) are common examples of image files that contain metadata. The metadata embedded in these images files basically serve as a method to access and retrieve further details of a particular image. Apparently, tagging pictures or images with essential and relevant subjects and keywords, emotions, and other descriptive details help for the image become easily and immediately searchable by Internet users.
Lastly, Flicker and Photobucket are among the many popular image tagging services currently available on the Internet. While being required of free registration, these services enable registered users to upload images and provide content on (tags) each uploaded image. Contents provided then increases for the searchability and access to these images on the Internet.