NewsIntroducing the Raspberry Pi Global Shutter Camera: Perfect for Sports Photography and...

Introducing the Raspberry Pi Global Shutter Camera: Perfect for Sports Photography and Machine Vision Applications

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Introducing the Raspberry Pi Global Shutter Camera: the latest addition to the Raspberry Pi camera family. Built around Sony’s 1.6-megapixel IMX296 sensor, this camera is capable of capturing rapid motion without introducing rolling shutter artefacts. This feature makes it a perfect fit for sports photography and machine vision applications, where even small amounts of distortion can seriously degrade inference performance.

The Sony IMX296 is a 1/2.9″ type CMOS image sensor with a resolution of 1440 x 1080 pixels (1.6 megapixels). It has a pixel size of 3.45 µm x 3.45 µm and features a global shutter to eliminate rolling shutter artifacts when capturing fast-moving objects. The sensor also includes an analog storage element for each pixel, allowing for instant capture of the pixel’s analog value when the shutter is fired. The IMX296 has a high-speed readout of up to 120 frames per second (fps) at full resolution, making it suitable for applications such as machine vision and sports photography. The sensor’s dynamic range is 75 dB, and it has a signal-to-noise ratio of 37 dB.

While all previous Raspberry Pi cameras have used rolling shutter sensors, the Global Shutter Camera uses a global shutter sensor to eliminate rolling shutter artefacts. Rolling shutter sensors have a two-dimensional array of light-sensitive pixels and a row of analogue-to-digital converters (ADCs) that convert analogue values into digital values. The row of ADCs is connected to each row of the pixel array in turn, which causes each row to be sampled at a slightly different time. When there is no motion in the scene, this is not a problem, but when things start to move, rolling shutter artefacts appear. Linear motion can cause compression, stretching, or shearing of the moving object, while rotary motion can create odd-looking shapes.

Rolling shutter sensors work by capturing an image by scanning the scene in a row-by-row or column-by-column manner. The image sensor is divided into rows or columns, each of which contains photosensitive pixels. The rows or columns are sequentially exposed to light for a short period of time, and then the signals generated by the photosensitive pixels are read out sequentially.

As each row or column is exposed and read out in sequence, there is a time difference between the exposure of the top and bottom of the image, or the left and right of the image. This means that if there is any movement in the scene during the exposure time, the position of the object being photographed can change slightly between the time the top and bottom of the image are captured.

This can result in distortion of the image, known as rolling shutter artifacts, which can cause vertical or horizontal stretching, compression or skewing of the image, depending on the direction of motion. This effect can be particularly noticeable when photographing fast-moving objects or when the camera itself is in motion.

Rolling shutter artefacts can interfere with machine vision algorithms, and even imperceptible artefacts can cause issues. This is where the Global Shutter Camera comes in, as it pairs each pixel with an analogue storage element. When the shutter fires, each pixel immediately copies its analogue value into its storage element, from where it can be read and converted at leisure. This eliminates rolling shutter artefacts altogether.

Although global shutter sensors tend to have lower resolution than rolling shutter sensors of the same size, the Raspberry Pi Global Shutter Camera combines the C/CS-mount metalwork of the High Quality Camera with Sony’s IMX296 sensor. It is compatible with a broad range of lenses, including the 6mm CS-mount and 16mm C-mount CGL lenses offered through Approved Reseller partners.

Like all Raspberry Pi camera products, the Global Shutter Camera can be used with any Raspberry Pi computer that has a CSI camera connector. The hardware documentation has been updated to include everything needed to know about the new product. To use the camera, you will need to update Raspberry Pi OS by typing “sudo apt update; sudo apt full-upgrade; sudo reboot” in the terminal.

The CSI camera connector, also known as the Camera Serial Interface (CSI) connector, is a hardware interface found on Raspberry Pi boards. It allows users to connect a compatible camera module to the board, which can then be used for image and video capture. The CSI connector provides a high-speed serial interface between the Raspberry Pi board and the camera module, allowing for high-quality image capture and processing. This interface is used by various Raspberry Pi camera modules, including the Raspberry Pi Global Shutter Camera.

Machine vision refers to the use of computer vision technologies to enable machines to interpret and understand images and videos in the same way that humans do. It involves the use of digital cameras and image processing algorithms to analyze images and extract information from them. This information can be used for a wide range of applications, including quality control, inspection, guidance, and measurement. Machine vision is used in many industries, including manufacturing, automotive, electronics, pharmaceuticals, and food and beverage production. It has become an important technology for automation and is often integrated with robotic systems to enable more efficient and accurate operations.

The Raspberry Pi Global Shutter Camera offers clear advantages for machine vision applications and is a welcome addition to the Raspberry Pi camera family. The hardware was designed by Simon Martin, while the software was developed by Naush Patuck, Nick Hollinghurst, David Plowman, Serge Schneider, and Dave Stevenson. Documentation was created by Alasdair Allan, Simon Martin, David Plowman, Andrew Scheller, and Liz Upton, and sourcing was led by Austin Su. Jack Willis designed the packaging, and Brian O Halloran took the photos and video. The Raspberry Pi Foundation would like to acknowledge the assistance of Phil Holden and John Conroy at Sony, and of Shenzhen O-HN Optoelectronic.

Michal Pukala
Electronics and Telecommunications engineer with Electro-energetics Master degree graduation. Lightning designer experienced engineer. Currently working in IT industry.