Microsoft has launched a new app that can scan a photograph and tell you the emotions it shows. Happy, sad or angry, once you upload your photos, the device will scan the image, detect the face and tell you what you were really feeling — making it impossible for people to hide their emotions from machines.

Microsoft's photo research division Project Oxford has come up with various tools so far, be it an app that tells a person's age, or Photosynth, which can rearrange photographs to resemble the 3D image of a place, Fastcoexist reported.

However, detecting emotions is a different game altogether.

The new system processes images and builds up on predictions; the suggestions keep improving as the number of images increases, according to Fastcoexist.

Once the images get processed, they are quantified on the basis of emotions such as anger, fear, happiness, disgust, sadness and surprise. In a simple test, an image of a grumpy cat and a man's image were uploaded. The site could not process the cat's image, but started working on the man's image almost immediately, the report further explained.

According to popular belief, machines could never read emotions, but now they can. However, in a practical-world scenario, testing the practicality of the site remains a challenge.

There are other emotion-recognising software such as, Affectiva, Eyeris and Nuance, Forcoexist reported.

One of the possible uses of the new device is to detect potential troublemakers on the basis of their emotional states. The technology might also come in handy to process CCTV footage at various places. The other use could be to determine the reactions of people seeing a plate of food or watching their favourite game, Fastcoexist reported.