Apple uses information from both regular cameras and telephoto lenses to get the required depth information.
This feature has been emulated by a number of device apps and manufacturers. However, without a dual camera, it is difficult to do. Samsung also adds these capabilities to the Galaxy Note 8 thanks to a double camera stock on the back.
Google also took part in capturing Portrait on its latest smartphone, the second generation Pixel, though without the support of dual cameras.
To be able to get the blur effect, Google uses two Pixel technology pinned on the camera sensor device.
Each pixel on the sensor is compromised into two separate pixels, being a feature that helps lighting and fast focus. Now Google also adds algorithms, tasked to analyze information from two Pixel to create depth mapping.
Depth mapping is background-related information, foreground, and the distance of different objects in an image.
Using the map, Pixel 2 and Pixel 2 XL will be able to simulate the natural blur effect of the pro camera.
The Portrait feature will also be available for selfie photos, the front camera of the two latest phones Google is also equipped with a Dual Pixel sensor. Google claims this technology works well, though some claim it still doubts it to make comparison with other devices.