Overview The ZED is a 2K stereo camera with dual 4MP RGB sensors, a 110° field of view and ƒ/2.0 aperture. The ZED streams uncompressed video at up to 100 FPS in WVGA format. It is an UVC-compliant USB 3.0 camera backwards compatible with USB 2.0. Selecting a Video Mode The left and right video frames are synchronized and streamed as a single uncompressed video frame in side-by-side format. You can change video resolution and framerate in the ZED Explorer or using the API. There are several video modes available: Video Mode Output Resolution (side by side) Frame Rate (fps) Field of View 2.2K 4416x1242 15 Wide 1080p 3840x1080 30, 15 Wide 720p 2560x720 60, 30, 15 Extra Wide WVGA 1344x376 100, 60, 30, 15 Extra Wide Selecting a View The ZED outputs images in different formats. You can select between rectified, unrectified and grayscale images: Left view Right view Side-by-side view Left or Right Unrectified Left or Right Grayscale For more information on how to access these views, see Video Capture. Adjusting Camera Settings The ZED camera features an onboard ISP (Image Signal Processor) that performs various image processing algorithms on the raw image captured by the dual image sensors. Several parameters of the ISP can be adjusted directly from the ZED Explorer app or through the ZED SDK: Resolution FPS Brightness – Controls image brightness. Contrast – Controls image contrast. Hue – Controls image color. Saturation – Controls image color intensity. Gamma – Controls gamma correction. White Balance – Controls camera white balance. Exposure – Controls shutter speed. Setting a long exposure time lead to an increase in blur. Gain – Controls digital amplification of the signal from the camera sensor. When the camera is in ‘Auto’ mode, parameters such as exposure, gain and white balance are automatically adjusted depending on the scene. Video Recording The ZED is a UVC camera so you can capture stereo video in MP4 or AVI format using any third-party software. However to use the ZED SDK, you will need to record your videos in Stereolabs SVO format. SVO files contains additional metadata such as timestamp and sensor data. When loading SVO files, the ZED API will behave as if a ZED was connected and live feed was available. Every module of the ZED API will be available: depth, tracking, spatial mapping and more. To record SVO videos, you can use the ZED Explorer application in GUI or command-line mode or build your own recording app using the ZED API. Compression modes SVO videos can be recorded using various compression modes. We provide both lossless and compressed modes to preserve image quality or reduce file size. Compression Mode Compression Ratio Quality (SSIM) CPU Load (%) GPU Load (%) Platform LOSSLESS (PNG) 2:1 100 32.0 0.0 Any LOSSY (JPG) 4:1 95.5 29.5 0.0 Any AVCHD (H.264) 100:1 96.9 3.1 5.0 Requires NVIDIA GPU for hardware encoding HEVC (H.265) 100:1 97.3 2.9 5.0 Requires NVIDIA GPU (Pascal or above) for hardware encoding Recording with Multiple Cameras You can record videos with multiple cameras connected to the same PC. When using hardware encoding (H.264, H.265), make sure to check the NVENC support matrix which shows the maximum number of concurrent recording sessions that can be started on a single NVIDIA GPU. You can also add multiple GPUs in a single server to increase the number of recording sessions with hardware encoding. Best Practice for Recording For optimal performance, we recommend using the H.264 and H.265 recording modes. They benefit from the hardware-based encoder (referred to as NVENC) built into NVIDIA graphics cards. With encoding offloaded to NVENC, the GPU and the CPU are free for other operations. For example, in a compute-heavy scenario, it is now possible to record video at full frame rate with minimal impact on the main application. For more information on capturing, playing and converting AVI and SVO video files, see the Recording samples on GitHub. Video Streaming The ZED SDK can stream the left and right images of the ZED camera. The Stream module sends video content over the network, so devices with the proper permissions can access the live feed from anywhere. When taking a stream as input, the ZED API will behave as if a camera was directly connected to the PC. Every module of the ZED API will be available: depth, tracking, spatial mapping and more. To stream the video content of a ZED camera, you can use the Camera Streaming Sample. Streaming modes The ZED SDK can stream images using either H.264 or H.265 encoding modes. Below are recommended streaming bitrates depending on the encoder, the target resolution, and the FPS. Encoder Resolution (side by side) FPS Bitrate (kbps) Platform AVCHD (H.264) 4416x1242 15 8500 NVIDIA GPU 3840x1080 30 12500 2560x720 60 7000 HEVC (H.265) 4416x1242 15 7000 NVIDIA GPU (Pascal or above) 3840x1080 30 11000 2560x720 60 6000 Streaming from Multiple Cameras You can stream videos from multiple cameras connected to the same PC. When selecting the encoding mode (H.264, H.265), make sure to check the NVENC support matrix which shows the maximum number of concurrent encoding sessions that can be started on a single NVIDIA GPU. Streaming Best Practices Both H.264 and H.265 encoding modes benefit from the hardware-based encoder built into NVIDIA graphics cards (known as NVENC). With encoding offloaded to NVENC, the GPU and CPU are free for other operations. For example, in a compute-heavy scenario, it is now possible to stream a video at full frame rate with minimal impact on the main application. For more information on streaming a video and using a stream as input, see the Streaming samples on GitHub.