7 Replies Latest reply on Apr 23, 2017 2:26 AM by 初學者

    set/get metering


      Can librealsense set or get the camera lighting metering such as: Matrix/Evaluative Metering, Center-weighted Metering and Spot Metering?

      I use RealSense R200 to do it.

        • 1. Re: set/get metering

          As far as I am aware, the most control you can get over the lighting level through scripting is to activate or deactivate the IR Emitter of the camera.  The IR Emitter is a component that helps the IR Camera to handle light exposure.  Aside from that, you should add or subtract lights yourself in the environment that you are using the camera in (for example, adding more lights to a room or turning some lights off) to get the best conditions.


          This is apparently the Librealsense instruction for the IR emitter.




          Example script:


          * Enables / disables R200 emitter


              public void setEmitterEnabled(int value) {

                  setOption(RealSense.RS_OPTION_R200_EMITTER_ENABLED, value);


          • 2. Re: set/get metering

            Actually, I want to use r200 just like smart phone camera, we can choose where the camera focus.

            I want to know the approach(matrix/evaluative, center-weighted or spot) r200 use to test lighting and is it possible to set the metering mode?

            Sorry for my bad English, I will try to explain more detail if you don't understand my meaning.


            for example:

              metering mode


            • 3. Re: set/get metering

              I forgot to say, I currently only use color stream, does the IR Emitter influence the color camera?

              • 4. Re: set/get metering

                I see what you mean now.  Your English is fine.  I'm just one of the few people who doesn't own a smartphone (my last mobile was a Nokia 3310 dumb-phone with the Snake game on it in 2002), so I didn't recognize the reference to camera focus. 


                The script linked to below has some lines starting at line 558 that sound like they could provide directional focus using the Auto Exposure



                librealsense/ds-device.cpp at master · IntelRealSense/librealsense · GitHub


                The IR Emitter mainly affects the quality of the IR and Depth types of stream.

                • 5. Re: set/get metering

                  According to librealsense/rs.h at master · IntelRealSense/librealsense · GitHub

                  The comment said that "Requires the \c RS_OPTION_R200_LR_AUTO_EXPOSURE_ENABLED option to be set to 1".

                  And RS_OPTION_R200_LR_AUTO_EXPOSURE_ENABLED /**< Enable/disable R200 auto-exposure. This will affect both the IR and depth images.*/


                  It said will affect both IR and depth images, but how about color image?

                  • 6. Re: set/get metering

                    When I said "The IR Emitter mainly affects the quality of the IR and Depth types of stream", I meant to say that the Color stream should be less affected by the IR emitter being on or off.  I'm sorry I did not make that clearer. 


                    Adding or taking away a light source, by having the emitter on or off, is sure to affect how light or dark the Color stream's image is.  But it probably would not affect the quality of an image as much as it does for the Depth and IR types of stream.

                    • 7. Re: set/get metering

                      It looks as though librealsense doesn't offer the metering mode for color camera.