It is practically impossible to stop people from copying and sharing your online images, however, here are some steps you can take to make unauthorised copying more difficult:
In the UK you automatically have copyright when you create an image. The copyright symbol does not have to be present for copyright to exist.
There may be cases when you may not do as you please with your images, for example:
If you create images during the course of your employment you would need your employer’s permission to re-use the image.
If you take a photograph of an art work on display in a gallery that is protected by copyright.
If you take photographs at a wedding you should not post them on your website or exhibit them in public without the permission of the couple getting married.
For more information see Copyright notice: digital images, photographs and the internet (Gov.UK)
Adding a small section of text, or a logo, to your images is one way of demonstrating ownership. You can add watermarks using software such as Adobe Photoshop, and Adobe Lightroom.
Making the watermark prominent is more effective but less pleasing to the eye than tucking it in a corner. However, watermarks are easily removed and therefore not very effective. Read the following blog for a debate of the pros and cons of watermarking: 7 Reasons Why You Should Stop Using Watermarks (Mastin Labs)
Sharing high-resolution images makes it easier for someone else to manipulate the image and pass it off as their own and makes it harder to prove you are the creator of the image. Compress the file size when you upload the image.
You can embed your copyright information straight into a JPEG file using Photoshop or similar photo-editing programs. However, it isn’t a very effective method as it isn’t visible to users that you have done it and most websites will strip metadata away from the file when compressing the file. You could use a Photoshop plug-in like Digimarc for Images which creates an invisible barcode within your file which is harder, but not impossible, to remove.
Photo sharing sites like Flickr have terms and conditions. Read them carefully to make sure you are not signing away your rights, for example, allowing them to use your images for their own commercial purposes or share them without your prior permission or informing you. The Creative Commons copyright licenses offer everyone a simple, standardized way to retain copyright and get the credit for their work they deserve, while allowing others to copy, distribute, and make some uses of their work.You can use Creative Commons tools to share your work either by choosing a Creative Commons License directly or by sharing on a platform such as Flickr.
There are various ways of stopping users from downloading your images by right-clicking and selecting copy or save. See Preventing visitors from downloading your images, videos, and audio
If you are worried that your images are being used you can use reverse image search engines such as TinEye to look for copies of your images.
Do not only protect your images, respect other people’s images as well by following the licence and giving due credit. You cannot assume that just because an image is on the web it is free for you to re-use as you wish.
Be careful not to accidentally reveal too much information about yourself especially on Social Media for example, your date of birth from a photo posted on your birthday, which might lead to someone stealing your identity. See the UoB Canvas Course on online security.
For further information including what to do if somebody uses your images without permission see
Protect online photos (Cambridge in colour)
How to protect your images online (Policy bee)
Copyright notice: digital images, photographs and the internet (Gov.UK)