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What the heck is Metadata?


Simply, Metadata is data about data. I know what you’re thinking, as far as definitions go this is not very helpful. But as they say “it is what it is.” To be more explicit Metadata is data providing information about one or more aspects of the data; it is used to summarize basic information about data which can make tracking and working with specific data easier. For example, a digital image may include metadata that describes how large the picture is, the color depth, the image resolution, when the image was created, the shutter speed, and other data.

What you should know is that metadata exists in almost all digital files such as documents, video and audio files, and web pages. For image files, the metadata that is contained is in an EXIF format. EXIF is a standard that specifies the format for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners, and other systems handling image and sound files recorded by digital cameras. EXIF data is embedded within the image file and works with JPEG images only. EXIF metadata can contain geolocation metadata in addition to a wide array of technical information. To buttress this point, I am going to use an image taken by my camera for illustrative purposes.

To view the metadata contained in the image taken by my camera, I used EXIF PILOT, a free EXIF editor that allows you to view, edit, and remove EXIF, EXIF GPS, IPTC, and XMP data in addition to adding new tags and importing and exporting EXIF and IPTC to/from text and Microsoft Excel files. Alternatively, you can use an online EXIF viewer application called JEFFREY’S EXIF VIEWER.



What you see above is EXIF metadata obtained from the photo which I just took, showing the model of phone and the time the photo was taken. The EXIF GPS tab circled by the blue pen and yellow arrow reveals the GPS coordinates (if available) of the photo when it was taken. This takes advantage of the ability of mobile phones to geotag the photos that they capture. I don’t think I have to emphasize on how much of a security risk this can become. Taking photos in your office or home with your location services turned on and uploading such on the internet can reveal your address information. Some social networking web sites remove the geolocation information and other metadata automatically before publishing it online. Twitter and Facebook do so, but some web sites do not. So, to be safe, always turn location tags off.





To edit or remove image file metadata you can use the EXIF PILOT tool, select the image file and click on the “Edit EXIF/IPTC/XMP” button. To remove metadata from pdf files you can use the PDF METADATA EDITOR if you have Java installed on your PC. You can also use a feature on Adobe pdf reader called “sanitize document” to remove pdf metadata. You can access it from the tools menu. To view/edit and remove audio file metadata, use Mp3tag. For Video files, MediaInfo is the preferred tool.



For Microsoft office files, first select the file, then go to the info tab. Click on properties then select advanced properties to open the advanced properties tab where you can edit the metadata.





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