D455 Poor depth quality
I have evaluated two different units of the D455 camera to calculate the depth to the surface of a small cylinder as a test (see middle of depth images). I get a 55mm error at 2m distance, and similar error in the 1.5m-3m range. I have tried all different presets, everything in the calibration guide, and all calibration routines excluding the OEM calibration.
The D435 camera performs better at the range of 1.5-3m with less than 2% per meter error, which is odd to me since the D455 should be 2x better.
RGB:
D435:
D455:
The two cameras run with the same options, at their optimal resolution, both have been calibrated with the dynamic calibration tool
Can the D435 outperform the D455 on the 1.5m-3m range like this?
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Hi Liam Neric The problem with the D455 depth image seems to occur with the depth nearest to the camera. the D435 has a minimum depth sensing distance of around 0.15 meters, whilst D455's minimum is around 0.5 meters.
I would therefore recommend excluding the possibility that the broken depth areas on D455 represent distance values that are nearer to the camera than 0.5 meters. You could test this using a setting called Disparity Shift that reduces the minimum distance of the camera and enables depth that is closer to it to be successfully included on the depth image.
1. Go to the Advanced Controls section of the RealSense Viewer's options side panel and expand open its options.
2. Expand open the Depth Table settings under Advanced Controls.
3. Find the Disparity Shift option, which has a value of 0' by default and change it to '200'.
Are the broken areas on the D455 depth images now rendered correctly?
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Thank you for your quick answer Marty.
The biggest depth problem is not under 1M, but between 1.5M and 3M distance.
Here is the result with disparity shift of 200
Does it require more fine-tuning to get the D455 to work in comparison to D415 and D435? I get the impression that I'm not the only customer that has difficulty with the depth quality of this camera.
BR, Liam
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The downside of Disparity Shift is that whilst increasing it above 0 reduces the minimum depth distance, increasing the value also progressively reduces the maximum observable depth range and strips out the background of the image, which looks as though what is happening to you when applying a DS of 200.
Aside from improved depth accuracy over medium to long range (3 to 6 meters) and a wider field of view size, the D455's depth sensing should perform similarly to that of D435.
Next, please try going to the Laser Power option under Stereo Module > Controls and setting it to its maximum value of '360' to see whether that helps to enhance the depth image.
You can also try resetting the D455 to its factory-new default calibration values in the RealSense Viewer with the instructions at the link below.
https://github.com/IntelRealSense/librealsense/issues/10182#issuecomment-1019854487
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