GoPro's new action camera fixes an annoying quirk with video stabilization

The GoPro Hero 7 Black increases softness.

The GoPro Hero 7 Black is not very different on the outside, but there is much more power inside.

A lot of action images are meant to give you a feeling of sinking in your stomach. Whether you're a mountain cyclist who takes a leap of faith in a big fall, or just a little boy in a home movie that faces the big slide on the playground for the first time, that POV view has a big impact when you see the pictures. Unfortunately, that type of shot can also come with another stomach feeling: mild nausea from shaky, shaky images. For its new Hero 7 Black camera, GoPro has developed a technology called Hypersmooth, but behind this sleek name is an advanced image stabilization technology that has been refining for more than four years.

Fighting the Milkshakes.

GoPro is using digital image stabilization, which means it is not based on moving parts inside the camera to counteract the tremor.

Like any type of vibration reduction, digital image stabilization requires a set of internal sensors that include an accelerometer to determine how fast the camera moves, as well as a gyroscope to observe the camera's rotation. Then the camera processors interpret that data to get a clear picture of how the camera is moving through space.

To translate this into softer images, the camera uses only part of its image sensor to capture video, leaving a buffer of inactive pixels around the edges. If the camera detects movement to the right, it moves the active pixel window to the left using that buffer. The sensor itself does not move, but the active pixel window does.

 "We cut about five degrees around the edges ," says Nick Gilmour, director of product management for GoPro. That's not an insignificant cut in the frame, but since GoPro works with a lens that is much wider than a typical smartphone, it still offers a massive field of view.

Smoothing the edges.

This kind of digital image stabilization has some internet limitations. For example, once you get to the edge of that buffer, you can get an abrupt stop that feels unnatural. To combat this effect, GoPro considered how the camera approaches those edges, creating a more gradual transition to the boundary rather than a difficult shutdown.

This ability to analyze a scene comes from the GoPro GP1 chip, which is a dedicated piece of image processing hardware that performs some functions similar to Google's Visual Core Pixel and the new Apple chip on the IPhone XS Max. The new GoPro Hero 7 now has 2 GB of RAM dedicated to processing image data and interpreting the information collected from the sensors.

As a result, the smoothing of the image that once occurred mainly in post-processing now occurs in real time during capture.

Absorbing the Talk

Where you really notice the difference in performance of the GoPro 7 Black are situations with many small potholes, or "talk " as some shooters call it. Imagine riding a mountain bike on a rocky trail or a road bike on bumpy/lumpy cobblestones. That kind of fast, shaky tremor is the nightmare of the footage from the action camera, so GoPro has been so focused on it.

That's the kind of cut that mechanical image stabilization devices such as built-in or gimbal-stabilized lenses with which the camera fights.  "There is an operational limit on mechanical stabilization," says Gilmour,  "And when it reaches that limit, it will have to be reset, which creates something discordant and unnatural ".

However, by using digital image stabilization, you can select a camera mode that trims the active area on the sensor even further and gives the sensor trimmed more space to bounce to soften things up even more.

Art and Engineering

While there are certain aspects of the performance of a camera that can be objectively measured, such as sharpness and digital noise, other decisions are more subjective.

For example, if engineers who build Hypersmooth technology have tried to mimic the appearance of a mechanical cardan, sometimes it creates what is called a "false horizon ", where everything in the distance remains level, even if your body and The camera's spinning. This effect is what makes the gimbals so effective for drones, but not ideal for action cameras. That eliminates some of the drama of the scenarios, like bending over a motorcycle.

The line between the right amount of smoothing and too much is also very thin. There were times when I tried the GoPro Hero 7 Black in which the images looked a little too soft, giving any movement a slightly floating sensation that is not necessarily representative of what I remember.

Still, when it comes to absorbing the little bumps that make the old images of the action camera unseen, the GoPro Hero 7 Black is really awesome. Just be careful: without unstable images, you will all see how slow it is to ride your next mountain bike video.

tags: Reviews, cameras, GoPro, video AI algorithms, processors, technology gadgets