View my account

D455 depth data sometimes has unstable values

Comments

3 comments

  • MartyG

    Hi Kawasyuuqq  When using auto-exposure, the first several frames may have incorrect exposure because the exposure value is still settling down (this does not occur when using manual exposure).  You can add a line to a script though to skip the first several 'bad' frames.  It should be placed directly before the wait_for_frames() line.

    for i in range(5):

     

    In regard to your second question, you can change the options in the RealSense Viewer's Controls section with code.  There are numerous options though, so if you request a specific one (such as exposure) then I can provide some Python code for it.

     

    If you plan to customize multiple Controls settings then it may be easier to set the values in the Viewer and then use the json save button near the top of the Viewer's options side-panel (beside the camera name) to export a json camera configuration file.  You can then load this json in using your script to apply the settings in the file.

     

    Most of the Advanced Controls do not have Python code available to alter them and also do not have documentation to describe what they do.  This is because the Advanced Controls interact with each other in complex ways, so Intel chose to control them automatically with machine-language algorithms instead of documenting them.

    0
    Comment actions Permalink
  • Kawasyuuqq

    Thank you very much. I tried it.

    for i in range(5):.
     frames = self.pipeline.wait_for_frames()
     time.sleep(10/1000)
    time.sleep(3)

    Multiple "pipeline.wait_for_frames()"
    and a 3-second wait.

    In addition, the exposure, gain, and laser power are adjusted manually.
    Each value is adjusted so that the object appears beautiful.
    (For example, if the exposure is set too high, the image will not look good every time.)
    However, it sometimes happens that the image does not stabilize during the subsequent shooting.
    When it was not stable, it was not stable even after dozens of shots.
    This can happen when using the extension repeater or not.
    In most cases, it can be fixed by disconnecting and reconnecting on the software.

     

    >If you plan to customize multiple Controls settings then it may be easier to set the values in the Viewer and then use the json save button near the top of the Viewer's options side-panel (beside the camera name) to export a json camera configuration file.  You can then load this json in using your script to apply the settings in the file.

    I understand. Thank you!

    0
    Comment actions Permalink
  • MartyG

    As manual exposure is being used, if there is an event that causes the image to become over-exposed or under-exposed then the camera will not be able to correct the image automatically if auto-exposure is not enabled.  An example of such an event would be if the camera was facing directly towards a bright light source such as the sun, causing the infrared sensor to become saturated with light. 

     

    If you do not wish to use auto-exposure then you could consider High Dynamic Range (HDR) mode, where auto-exposure is disabled and the camera can alternate between two different exposure values.  This helps the camera to deal with scenes where there are both bright and dark areas.

    https://dev.intelrealsense.com/docs/high-dynamic-range-with-stereoscopic-depth-cameras

    0
    Comment actions Permalink

Please sign in to leave a comment.