Image metadata is additional data stored alongside the image that describes its properties. This information helps software correctly display the image.
Key points
Definition:Metadata: data about data — additional information stored with a file that describes its properties.
Image metadata can include: file format, resolution, colour depth, date taken, device used, file size.
Metadata is needed so that software knows HOW to correctly display or process the image.
Exam Tip:If asked to give examples of metadata, always link them to the IMAGE context — height, width, colour depth, date, geolocation, file size, file type, author.
Metadata adds a small amount to the overall file size but is essential for the image to be interpreted correctly.
Common Mistake:Saying metadata 'stores the colour of each pixel'. Metadata stores PROPERTIES of the image (like dimensions, colour depth), NOT the pixel data itself.
Exam Tip:'Resolution' counts as ONE metadata item. If you also give 'height' and 'width' separately, max 2 marks for all three combined (resolution = dimensions = height + width).
Exam Tip:'Colour' alone is NE. Write 'colour depth' or 'bit depth'. 'Size' alone is NE — write 'file size'.