MIPI Camera vs USB Camera
Over the past few years, embedded vision has evolved from a buzzword to a widely adopted technology used across industrial, medical, retail, entertainment, and farming sectors. With each phase of its evolution, embedded vision has ensured a significant growth in the number of camera interfaces available to choose from. However, despite the technological advancements, MIPI and USB interfaces have remained the two most popular types for a majority of embedded vision applications.
MIPI Interface
MIPI (Mobile Industry Processor Interface) is an open standard and a specification initiated by the MIPI Alliance for mobile application processors. MIPI camera modules are commonly found in mobile phones and tablets, and support high-definition resolutions of more than 5 million pixels. MIPI is divided into MIPI DSI and MIPI CSI, which correspond to video display and video input standards, respectively. At present, MIPI camera modules are widely used in other embedded products, such as smartphones, driving recorders, law enforcement cameras, high-definition micro cameras, and network surveillance cameras.
MIPI Display Serial Interface (MIPI DSI ® ) defines a high-speed serial interface between a host processor and a display module. The interface enables manufacturers to integrate displays for high performance, low power consumption, and low electromagnetic interference (EMI), while reducing pin count and maintaining compatibility between different suppliers. Designers can use MIPI DSI to provide brilliant color rendering for the most demanding image and video scenarios and support the transmission of stereoscopic content.
MIPI is the most commonly used interface in today’s market for point-to-point image and video transmission between cameras and host devices. It can be attributed to MIPI’s ease of use and its ability to support a broad range of high-performance applications. It also comes equipped with powerful features such as 1080p, 4K, 8K and beyond video and high-resolution imaging.
MIPI interface is an ideal choice for applications like head-mounted virtual reality devices, smart traffic applications, gesture recognition systems, drones, facial recognition, security, surveillance systems, etc.
MIPI CSI-2 Interface
The MIPI CSI-2 (MIPI Camera Serial Interface 2nd Generation) standard is a high-performance, cost-effective, and simple-to-use interface. MIPI CSI-2 offers a maximum bandwidth of 10 Gb/s with four image data lanes – each lane capable of transferring data up to 2.5 Gb/s. MIPI CSI-2 is faster than USB 3.0 and has a reliable protocol to handle video from 1080p to 8K and beyond. In addition, owing to its low overhead, MIPI CSI-2 has a higher net image bandwidth.
The MIPI CSI-2 interface uses fewer resources from the CPU – thanks to its multi-core processors. It is the default camera interface for Raspberry Pi and Jetson Nano. The Raspberry Pi camera module V1 and V2 are also based on it.
Limitations of MIPI CSI-2 Interface
Even though it is a powerful and popular interface, MIPI CSI does come with a few limitations. For instance, MIPI cameras rely on extra drivers to work. It means that there is limited support for different image sensors unless embedded system manufacturers really push for it!
Advantages Of MIPI:
The MIPI interface has fewer signal lines than the DVP interface. Because it is a low-voltage differential signal, the interference generated is small, and the anti-interference ability is also strong. 800W and above all use MIPI interface. The smartphone camera interface uses MIPI.
How it works?
Typically, the ultra-compact board in a vision system supports MIPI CSI-2 and works with a high range of intelligent sensor solutions. Moreover, it is compatible with many different CPU boards.
MIPI CSI-2 supports the MIPI D-PHY physical layer to communicate to the application processor or System on a Chip (SoC). It can be implemented on either of the two physical layers: MIPI C-PHY℠ v2.0 or MIPI D-PHY℠ v2.5. Therefore, its performance is lane-scalable.