Image format for custom text
Is there a way to add text to an image, embedded in the digital file itself, not necessarily something that would be visible on the photo in a viewer? What I'm thinking of is something like an IPAD with a camera, so I can take a photo and add text to it using the Ipad soft keyboard. Maybe the file format would be a tiff? Then access the enbedded text with software so I could sort the images based on the text.