How OIS and EIS -Image Stabilization Works? Explained

We all love to take photos and videos with our smartphone and sometimes when our hands are not still or the background is dimly lit while taking photos or videos then the captured results come out to be blurry & shaky which totally ruins the moment you wanted to capture.

In this scenario, the Image Stabilization techniques such as Optical Image Stabilization and Electronic Image Stabilization plays an important role in providing the end result stable.
Both OIS and EIS are completely different on the basis of their implementation but they both do the same job of stabilizing the photos and videos.

Optical Image Stabilization (OIS)

It is obvious when your camera's shutter speed is high then it opens and closes very fast, which reduces the time to hold your device steady to capture something. However, if your shutter speed is low for example if you are shooting in poor lighting condition then you need to keep your hands steady for a longer period of time and if your hand moves a little bit then your end result may be blurred.

This blurring caused due to movement of hands or sudden quakes during filming video is compensated by OIS technique.

It requires hardware to counteract the movement of the phone while taking snaps or videos. It uses an assembly of floating lens, gyro-sensor and a motor accompanied by a microcontroller to control the movement of the floating lens.

It keeps the track of the phone movement by using the data from gyro-sensor, this data is then sent to the microcontroller chip which decides the movement of the floating lens. For example, if the device is moved toward right then the lens will move toward the left to offset the device movement and hence the footage comes out to be more stable from a phone having OIS than a phone without stabilization.

All these things such as data retrieving from gyro-sensor then sending to the microcontroller and the movement of the floating lens happens before the image hit the CCD (Charged Coupled Device) and hence we do not degrade the quality of the footage.
The Nokia Lumia 920 was the first smartphone to have OIS support and now flagships from top brands like Apple, Samsung, Google, and LG etc., offers the same.

Pros 

It reduces the shakes in the video and negates the blurriness in the pictures taken. It increases the image quality of the footage shot.

Cons

• OIS assembly increases the size of the camera module which affects the sleekness of the smartphone. Camera hump is often seen on the phones having OIS.
• OIS is found on High-End smartphones because it adds a lot to the cost of the device and makes the phones bit pricey.
• It can not be upgraded with the software updates, you have to get it replaced.

Electronic Image Stabilization (EIS)

This technique is completely different from the previous one as it does not require any kind of hardware for its implementation.

Most of us edit the videos and photos after we have taken them to make them watchable.

Every camera has CCD (Charged Coupled Device) which is nothing but an array of numerous light sensors arranged in a grid, which captures the optical light and convert it into digital signals.

In this technique, the videos and photos are divided into small chunks or frames and then with the help of algorithms, the processor compares the frames whether the motion in the frame is an object or it is an unwanted movement, then it takes the required action to make the videos and photos stable.
Actually, in EIS the blurred out frames are cropped and then joined together to provide a stable result without degrading the image quality too much.
Most of the phones such as Oneplus 5t, Huawei Honor View 10, and Google Pixel & Pixel XL etc., uses the EIS technique for stabilization.


Pros

• It does not require any hardware component so it can be enabled with OTA update on any smartphone having a Gyro-sensor and a capable processor to hold up the processing.

• It can be upgraded via OTA updates by changing the algorithm.

Cons

• It increases the battery consumption because it uses the processor extensively in post-processing of the image.

• It is supposed to work fine in daylight but in the dimly lit condition it may suffer a bit but if the device has larger camera sensor then it will work fine.

There are some phones such as Google Pixel2 /Pixel 2 XL and LG V30  which uses both EIS and OIS for stabilization, the processor automatically decides where to use OIS and EIS. The OIS performs better in taking still shots and EIS do perform better in videos.



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