In the past two years, we have successfully developed a method that uses lasers to detect movement behind shielding barriers. Using this method, they are able to detect not only the location of objects behind barriers but also the movements of these objects.
It is still in the research stage, but in the near future, it is hoped that these laser-based cameras will be installed in unmanned vehicles and rescue areas for people trapped in the rubble.
This time, the Stanford Computational Imaging Lab has developed a method that can capture images inside a sealed room by injecting a laser through a small hole. This technology is called non-line-of-sight imaging. It is called the keyhole imaging system (Keyhole imaging) for short.
This technology is a system that can shoot a laser beam through a keyhole-sized hole and take pictures of objects in the room. It’s a computer that uses a computer to project a laser beam from a small hole onto the objects in the entire room.
This blind imaging technology is not entirely new. However, previously developed blind imaging cameras can only detect the back of places, such as corners of the wall. I was able to make out images behind a few barriers, but not to the point where I could make out the objects in the entire room.
In the previously developed methods, the imaging method is to use reflective surfaces such as brick walls and smooth floors. This wall or floor needs to be in the field of view of both the camera and the subject.
In order to create an image behind this shield, we first need to inject light through the camera. This light will reflect on the wall and reach the object to be photographed. The incoming light is reflected from this object and returns to the camera through the wall or nearby walls and floors.
The computer calculates how long it takes for this reflected light to return and from which angles it returns. This computer calculates and retrieves the image of the hidden object.
The resulting images are not very clear. But it is enough to classify what kind of object the hidden object is.
This method is a unique creation. But it has a big limitation. That is why a large screen is needed to reflect light. It is necessary to have a wide wall that will reflect light or a floor that will reflect light.
Using this method, it is not yet possible to detect people or objects in a closed room. But the lab could develop a system that would allow detection in a closed room.
The reason why this method is called a keyhole imaging system is because to image the room with this method, only a small hole is needed. From this hole, a small laser beam was injected into the room. The laser hit the wall on one side of the room. Because the laser line is small, the light that will appear on the other wall is only the size of a dot.
The laser light falling on this side wall is reflected off this wall and spreads into the room. The emitted light bounces off the objects in the room, then bounces off the wall and returns to the original camera through the keyhole. The time it takes for this returning light to return is calculated and imaged with a computer.
In this way, not all the objects in the room can be imaged. If the hidden object is motionless and still, the imaging computer will not be able to render it. But if the object is moving, it will cause enough light reflection that the imaging computer can calculate.
Another disadvantage is that it takes a long time to inject the laser beam and produce an image. How long it takes to inject is not disclosed by the inventors. Only when the laser beam is injected for a long time can an image be made from the returned light.
Also, the quality of the resulting image is quite poor. But if you can use powerful AI (Artificial Intelligence) technology, you can predict what the resulting image will be.
Currently, it is not capable of producing images of good enough quality to be useful. But scientists believe that one day they will be able to develop cameras of such high quality that they can accurately distinguish objects in a room.
In the future, this technique could be used for surveillance purposes so that police can see if a room is safe before entering it. In addition, unmanned vehicles and drones can be used to foresee obstacles.
