Did you always wanted to have a SLR camera because your Android Smart phone or Tablet does not give you that depth in your photos or won’t give you the option of focusing the foreground and blur the background. These features were only possible with cameras with bigger lens and aperture but now you can do all these with you Smart phone. Yea you heard it right! Google has come out with its Lens Blur in its new Camera app.
With this Lens Blur app you now make any object come in to focus just by tapping on it and changing the depth-of field slider you can adjust the aperture size to get the bokeh effects from subtle to surreal. This change takes place in real time allowing you to see the changes instantly on to the image. The changes or the effects can be given to the image once it’s been captured and the level of focus can be adjusted.
How does the Lens Blur work?
Many of you might wondering how this app will be working or how can a camera with small lens and aperture can do this, Lens Blur just replaces the need for the larger optical system by algorithms that will be stimulating a larger lens and aperture and by this you will be able to capture many frames just by a upward sweep of the camera instead of taking just one image. Later from these photos the app uses the computer vision algorithms that will be creating a 3D model of the image by estimating the depth to every point in the back ground.
After we get the 3D pose of images, the depth of each pixel is computed in the reference photo by using the MVS (Multi-View Stereo) algorithm. Now MVS works similar to the human stereo vision like giving the location of one object in two different images. By triangulating the 3D position of this object in the image the distance is computed. Later MVS measures the pixels from both the images and calculates how similar they are by computing the Sum of Absolute differences (SAD) of the RGB colors of the two pixels. To encounter the optimization problem this app uses the Markov Random Field inference (MRF) method.
After all these things are done the re-rendering of the image starts and the blurring of the pixels will take place depending on the depth of the pixel, aperture and the location that is relative to the focal plane that determines which pixel to blur. The amount of blur increases proportionally with the distance of each pixel to that focal plane.
All these algorithms run on mobiles and create this 3D photo that is very much related to the computers vision algorithm that is used in the 3D mapping features of Google like the Google Maps and Google Earth. Now enjoy the SLR like images on you Android Smart phone or Tablet with this updated Google app.
Download Google Camera for Android: Play Store Link