Embedded vision continues to gain prominence in IoT, AI, and other different technology-based applications. Thus, it comes as no surprise that businesses are starting to look for ways to integrate more advanced imaging capabilities and features into their respective products cost-efficiently. And for many applications and products, the MIPI or Mobile Industry and Processor Interface is fast becoming the most convenient and popular way of interacting host processors with cameras.
In this article, we’ll give you a brief overview of MIPI interfaces and cameras. Continue reading if you want to know more.
MIPI interface evolution
The MIPI interface architecture’s original standard was the CSI-1, which defined the host processor and camera interface. In 2005, MIPI CSI-2’s first version was released with protocols divided into specific layers, including the physical, lane merger, low-level, byte-to-pixel, and application layers. In 2017, its second version came out, supporting RAW-20 and RAW-16 color depths. Additionally, it has the capacity to reduce LRTE and improve virtual channels. In 2019, its third version was made available and supported RAW-24.
In 2012, the CSI-3 was released, with its subsequent iteration following shortly in 2014. Its difference from its predecessor is that it came with bidirectional and high-speed protocols for video and image transmissions between hosts and cameras.
CSI-2 vs. USB
Theoretically, the USB interface’s maximum bandwidth is five gigabits every second, and it’s not beyond the realm of possibility to achieve bandwidths of over three gigabits every second. Unfortunately, this limits the vision system’s ability to be utilized in various applications to effectively transfer data and images quickly for analysis and processing purposes. With CSI-2, you’ll have six gigabits of maximum bandwidth to work with, making it faster and more efficient in comparison.
In MIPI cameras, the sensors capture the images and transmit them to CSI-2 hosts. When they’re transmitted, the images are placed into the memory in the form of individual frames, each one being individually transmitted via virtual channels. As a result, the MIPI camera permits the complete transmission of images using the same sensor, although with multiple streams of pixels. The CSI-2 utilizes communication packets that include error correction codes and data format functionality, with single packets traveling through D-PHY layers before splitting into the necessary data lanes.
Then, the receivers are provided with the D-PHY layers for decoding and extracting the packets. This process is generally repeated for every frame through low-cost and efficient implementation. And the reason why CSI-2 interfaces are increasingly becoming commonplace is that they make the integration process much easier. Moreover, it’s possible to interface the camera modules with multiple processors, including but not necessarily limited to Windows, Android, and Linux-based systems.
With its cost-effectiveness, compatibility, and efficiency, it’s easy to see why MIPI interfaces and cameras are becoming the preferred option over the alternatives when it comes to embedded vision. However, you must still choose the right manufacturer or supplier before you decide on which product to go for, as not all are made the same. So do your due diligence first, as it will make a difference.