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D415 gets the real distance

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4 comments

  • MartyG

    Aalignment is not necessary to obtain the real-world depth distance in meters, and color data is also not required to do so.  The RealSense SDK has a C++ example program called rs-hello-realsense which makes use of get_distance() to print the distance to an observed object as a plain text value without graphics.

    https://github.com/IntelRealSense/librealsense/blob/master/examples/hello-realsense/rs-hello-realsense.cpp

     

    It is not necessary to calibrate the camera in order to obtain the distance, though you may wish to consider performing a calibration if the depth values appear to be significantly inaccurate.

     

    There are a range of factors that could cause the depth image to fluctuate.  Using the Temporal Filter post-processing filter in the Viewer to set its Alpha option to a value of '0.1' can help to stabilize fluctuations, as described at the link below.

    https://support.intelrealsense.com/hc/en-us/community/posts/17464300886675/comments/17528762276243

     

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  • 2935253854

    Whether all realsense camera is fixed or not, the depth map will fluctuate, as shown in the figure below, the area framed with the red rectangle will fluctuate

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  • MartyG

    The furthest left area next to the vertical black strip at the edge is called the Invalid Depth Band, an area empty of depth detail.  More information on this can be found on page 87 of the current edition of the data sheet document for the 400 Series cameras at the link below, though there is not much that can be done about it.

    https://dev.intelrealsense.com/docs/intel-realsense-d400-series-product-family-datasheet

     

    In regard to the area of black in the bottom corner next to the blue oval area, what color is the surface in that black area, please?  If it is black or gray colored then the camera would have difficulty reading depth detail from it.   This is because it is a general physics principle (not specific to RealSense) that dark grey or black absorbs light and so makes it more difficult for depth cameras to read depth information from such surfaces. The darker the color shade, the more light that is absorbed and so the less depth detail that the camera can obtain.

     

    You could try resetting the camera to its factory-new default calibration in the RealSense Viewer using the instructions at the link below to see whether the dark red area illustrated by the middle rectangle becomes more accurate.

    https://github.com/IntelRealSense/librealsense/issues/10182#issuecomment-1019854487

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  • 2935253854

    Thank you for your patience

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