Video CompressionĬurrently our lab collects video data at 480 x 480 pixels resolution, 30 fps, 8 bits per pixel. This resolution both minimizes the unused pixels on our arena border and yields approximately 800 pixels area per mouse. Zoom and focus were set manually to achieve a zoom of 8px/cm. One camera and lens was mounted approximately 100cm above each arena to alleviate perspective distortion. Overnight, we use FFmpeg software () to apply a 480x480px crop, de-noise filter, and compress using the mpeg4 codec (quality set to max) using the YUV420P pixel format, which yields a compressed video size of approximately 600MB. Our typical assays run for two hours, yielding a raw video file of approximately 50GB. Files were saved temporarily on a local hard drive using the “raw video” codec and “pal8” pixel format. This in turn reduced amplification of baseline noise. Aperture was adjusted to its widest so that lower analog gains were used to achieve the target brightness. Exposure time and gain were controlled digitally using a target brightness of 190/255. Data was acquired at 640x480px resolution, 8-bit monochrome depth, and 30fps using Sentech cameras (Model: STC-MB33USB) and Computar lenses (Model: T3Z2910CS-IR). Video Acquisition Imaging HardwareĪll data was acquired using the same imaging equipment. Difference previews are amplified 2x to enhance visibility. Original sub-panel of video and differences between original and compressed frames. Visual examples of some of the compression tests.
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