Video Input Requirements

to ensure a reliable assessment of health parameters from video, the recording must meet specific input requirements as a commitment to maintaining a quality first approach, we refrain from delivering results when accuracy cannot be guaranteed due to unmet input requirements in such cases, the face scan plug in provides clear guidance on how to improve conditions or perform the measurement correctly if requirements still cannot be met due to factors outside the user’s control – such as slow internet or poor lighting – the plug in will notify your platform, allowing you to handle the situation gracefully subject and environment subject stillness and position it is important for the subject to remain still during the recording and center the face within the recording frame the goal is to keep looking at the camera and minimize head movement the setup is similar to when taking a portrait photo lighting it is important to perform the recording in a well lit room a lighting of at least 200 lux is recommended our face scan plug in automatically guides the user to a correct position and lighting prior to starting the scan for comprehensive guidelines on how to correctly sit in front of the camera during the measurement, refer to our docid\ jud0qrczbbcutskbyezu0 recording frame rate the video frame rate should at least be 20 fps the recommended value is a recording frame rate of 30 fps the face scan plug in automatically checks whether the framerate is sufficient and prompts the user if it's not if in doubt, we recommend using a tool like https //www metadata2go com to verify your camera's performance the r frame rate field should contain a value of at least 20 fps resolution and codec the video resolution, codec, and bitrate are critical properties to consider when capturing and processing video data for measuring the biomarkers using our algorithm these factors play a vital role in preserving the necessary information about the blood volume pulse, which is essential for accurate measurements resolution at least 480p codec h264 or h265 if supported; vp8 or vp9 when recording in most browsers bitrate depending on resolution and codec, see table below our face scan plug in automatically checks whether these requirements are met and prompts the user if it's they're not more info on why these parameters are important video resolution refers to the number of pixels contained in each frame of the video higher resolutions provide more detailed images, allowing for better visualization and analysis of subtle color variations in the skin the choice of codec, which determines how the video is compressed and encoded, can have an impact on the fidelity of the captured data some video codecs employ heavy compression techniques that can introduce artifacts or loss of detail in the video it is important to select a codec that preserves color information and minimizes compression artifacts, as these artifacts can interfere with the accurate detection of subtle skin color changes camera camera sensor size & pixel size the camera sensor is the part of the imaging system that is sensitive to light the size of this sensor plays an important role in the final quality of the image or video the larger the sensor , the more sensitive it is to light larger image sensors have larger pixels, which means less noise, better dynamic range and the ability to obtain more (subtle) information the size of the sensor should be at least 5 0 mm in diagonal the size of a pixel (unit cell) should be at least 1 0 μm these values are standard for most smart devices and laptops from the last 5 to 6 years for example, the front camera of the samsung galaxy s8 from 2017 meets these requirements lens quality lens quality is becoming more important with the increasing pixel count on modern cameras the resolution of digital photos is often limited by the camera lens rather than the resolution of the camera itself in order to perform a qualitative measurement, the lens should be made from glass or an (optically) higher quality material lenses of lower quality (e g plastic) may work, but this is not guaranteed, as these materials scratch up more easily and the optical quality varies greatly