Every time you upload a photo to Facebook or any other of the company's services, tags are automatically added. One of the reasons for this addition is that tags can help people with visual impairments understand photos that have been posted on Facebook (according to the company).
However, the fact shows how much they have developed the algorithm on Facebook. Needless to say that every tag or label is automatically added to the big data of the largest social network.
And while the image recognition algorithm of Facebook continues to evolve to improve existing services, such as search or to ensure that images do not violate the social network's policies, it can also add information that is not part of the image's metadata.
The algorithm that analyzes images on Facebook mostly adds basic tags, such as sky, tree, cat, and other words that define the image.
Since April 2016, Facebook automatically adds alt tags to the images you upload, making them filled with keywords that represent the content of your images. The tagging of your images is done by the Deep ConvNet developed by Facebook's FAIR team.
If you're interested in learning how and which tags Facebook adds to the circulating photos, you can install a browser add-on that reveals them.
Show Facebook Computer Vision Tags is a browser add-on for Chrome and Firefox. After installation, all you need to do is visit Facebook. You will notice that in the photos on the social network, you will also see the tags in the upper right corner.
The tags exist only on photos that someone uploaded and not on images that were added via a link.
The images you see that have no tags exist because the image recognition algorithm of Facebook had problems detecting the image.
It appears that the algorithm does not work correctly for all images and certainly keeps Facebook's technicians busy. However, as you will notice, it does a very good job for most photos on the website.
