3D Structured Camera VS 3D Line Camera - What’s the Difference

August 12,2022

Among the abundant products of industrial cameras, the pearl on the crown is definitely 3D camera. It can detect materials and feed back results which naked eyes can’t see. But have you wondered the difference among all these 3D cameras and which one is the right one for you?


What is 3D camera


3D structured light camera



Today, many 3D cameras use structured light technology. This technique also uses triangulation, but works by projecting patterns of light onto the object to be scanned rather than laser lines (or points). Use an LCD projector or other stable light source to project the pattern onto the object. One or more sensors (or cameras), slightly offset from the projector, look at the pattern shape of the light and calculate the distance to each point in the field of view. The structured light used in the scanning process can be white or blue, and the pattern of light usually consists of a series of stripes, but can also consist of a matrix of points or other shapes.


The advantage of structured light technology is its fast scanning speed. The scan can be completed in about 2 seconds, and the scan area is also large. Just like laser scanners, structured light scanners are very accurate and have high resolution.

One of the drawbacks of structured light cameras is that they are sensitive to lighting conditions in a given environment. For the laser camera, it can be a good job. Lasers can direct bright light over a narrow range of wavelengths, so they work best in almost any environment. At close range, it also works with highly transparent and reflective objects such as glass. On the whole, the laser camera will be better in application scenarios and robustness.


If you want to know more information about 3D structured camera, here’s a more detailed blog to further illustrate.


3D laser camera



The laser camera is based on triangulation and can accurately capture 3D shapes (millions of points). More precisely, they work by projecting a laser point, or laser line, onto an object and then using sensors to capture its reflection. Since the position of the sensor and the distance from the laser source are known, accurate point measurements can be made by calculating the reflection Angle of the laser. With the knowledge of the scanner's distance to the object, the scanning hardware can map the surface of the object and thus record the 3D scan.

This method is called triangulation because the laser point (or line), sensor and laser emitter form a triangle, as shown below. There are many different types of laser scanners on the market and you can choose between handheld devices, desktop devices or professional/industrial devices. The point is that they can work over short distances. Lasers also have the powerful advantage of directing bright light over a narrow wavelength range, so they work well and stably in almost any environment.


In 3D cameras, the light source is replaced by the laser emitter. Through the complex optical system design, the laser emitted by the laser emitter will form a straight line, and the laser will be reflected on the surface of the object. Under the design of the optical system, the reflected light will be captured by the lens, and finally reflected to the photosensitive chip through the lens. Therefore, the three most important components of 3D camera are laser emitter, lens and photosensitive chip respectively. At the same time, some FPGA or ARM will be added for graphics processing, such as image algorithm and image filtering. In general, the laser emitter needs excellent optical engineers to design, for example, different lenses reflect the laser will have different effects; Basically, the lens is the normal lens we see, and the photosensitive chip usually chooses the high-precision CMOS chip.


Generally we refer to the laser line direction as the X direction, that is, the line radiated by the laser is defined as the X axis, and the height is defined as the Z direction. By taking a static photo, we can obtain the data in both the X and Z directions, and the Y direction, we generally refer to the direction of motion as the Y direction, that is to say. We can move the camera or the object, and let the camera continuously take pictures, to form continuous Y direction data, finally combined together, is the 3D data we need.


Difference of two types of cameras



Here at SmartMoreInside, we guarantee the perfect products of both 3D laser camera and 3D structured camera. With a professional team for guidance, you can surely figure out the right camera for your business.