To get better Depth for Exploration of UAV

Conclusion : Use Presets!!! unless under static, fixed scene situation.

Also use Post-Processing!!!

Almost of the contents from the guides are trying to tune the lots of parameters based on the scene-dependent situations.
Referred from here and here2
Official Tuning Guides Read through followings

● Result

Left: Default, Right: Default with post-processing

Left: High Accuracy, Right: High Accuracy with post-processing

Left: Default, Right: High Accuracy with post-processing

● Tuning depth cameras for best performance

848x480 resolution is recommended for D435 at 30fps.
Increasing the gain tends to introduce electronic noise, Keep gain as low as possible (preferably 16).

● D400 Series Visual Presets

The “High Accuracy” preset will impose stricter criteria, and will only provide those depth values that are generated with very high confidence.
- This will give a less dense depth map in general but is very good for autonomous robots where false depth are much worse than no depth.
~~Download the presets from here~~
Save the presets in realsense-viewer within SDK. Set the json file from custom or default to HighAccuracy and set other parameters you want, and the export that .json file.
Place the preset .json file in the .launch

  <arg name="json_file_path"      value="file_directory_and_name.json"/>

● Use Post-Processing filters with ROS package

Post-processings can be set using args in the launch file. filters can be checked here
- Supported filters: colorizer, disparity, spatial, temporal, hole_filling, decimation, pointcloud
- Note that decimation filter makes depth image downsampled, which results in changed focal length and principal points of intrinsic calibration.

    <!--arg name="filters" value="pointcloud,disparity,spatial,temporal,decimation"/-->
    <arg name="filters" value="pointcloud,disparity,spatial,temporal"/>

● Filter and .json file with emitter off

Download emitter off.json
- infra camera at 30 fps, 640x480
Download Mid resolution with High accuracy and emitter off.json
- infra camera at 30 fps, 640x480
- or simply copy-paste below:

{
    "aux-param-autoexposure-setpoint": "1536",
    "aux-param-colorcorrection1": "0.298828",
    "aux-param-colorcorrection10": "-0",
    "aux-param-colorcorrection11": "-0",
    "aux-param-colorcorrection12": "-0",
    "aux-param-colorcorrection2": "0.293945",
    "aux-param-colorcorrection3": "0.293945",
    "aux-param-colorcorrection4": "0.114258",
    "aux-param-colorcorrection5": "-0",
    "aux-param-colorcorrection6": "-0",
    "aux-param-colorcorrection7": "-0",
    "aux-param-colorcorrection8": "-0",
    "aux-param-colorcorrection9": "-0",
    "aux-param-depthclampmax": "65536",
    "aux-param-depthclampmin": "0",
    "aux-param-disparityshift": "0",
    "controls-autoexposure-auto": "True",
    "controls-autoexposure-manual": "8500",
    "controls-color-autoexposure-auto": "True",
    "controls-color-autoexposure-manual": "166",
    "controls-color-backlight-compensation": "0",
    "controls-color-brightness": "0",
    "controls-color-contrast": "50",
    "controls-color-gain": "64",
    "controls-color-gamma": "300",
    "controls-color-hue": "0",
    "controls-color-power-line-frequency": "3",
    "controls-color-saturation": "64",
    "controls-color-sharpness": "50",
    "controls-color-white-balance-auto": "True",
    "controls-color-white-balance-manual": "4600",
    "controls-depth-gain": "16",
    "controls-laserpower": "150",
    "controls-laserstate": "off",
    "ignoreSAD": "0",
    "param-amplitude-factor": "0",
    "param-autoexposure-setpoint": "1536",
    "param-censusenablereg-udiameter": "6",
    "param-censusenablereg-vdiameter": "7",
    "param-censususize": "6",
    "param-censusvsize": "7",
    "param-depthclampmax": "65536",
    "param-depthclampmin": "0",
    "param-depthunits": "1000",
    "param-disableraucolor": "0",
    "param-disablesadcolor": "0",
    "param-disablesadnormalize": "0",
    "param-disablesloleftcolor": "0",
    "param-disableslorightcolor": "1",
    "param-disparitymode": "0",
    "param-disparityshift": "0",
    "param-lambdaad": "751",
    "param-lambdacensus": "6",
    "param-leftrightthreshold": "10",
    "param-maxscorethreshb": "2893",
    "param-medianthreshold": "796",
    "param-minscorethresha": "4",
    "param-neighborthresh": "108",
    "param-raumine": "6",
    "param-rauminn": "3",
    "param-rauminnssum": "7",
    "param-raumins": "2",
    "param-rauminw": "2",
    "param-rauminwesum": "12",
    "param-regioncolorthresholdb": "0.785714",
    "param-regioncolorthresholdg": "0.565558",
    "param-regioncolorthresholdr": "0.985323",
    "param-regionshrinku": "3",
    "param-regionshrinkv": "0",
    "param-robbinsmonrodecrement": "25",
    "param-robbinsmonroincrement": "2",
    "param-rsmdiffthreshold": "1.65625",
    "param-rsmrauslodiffthreshold": "0.71875",
    "param-rsmremovethreshold": "0.809524",
    "param-scanlineedgetaub": "13",
    "param-scanlineedgetaug": "15",
    "param-scanlineedgetaur": "30",
    "param-scanlinep1": "155",
    "param-scanlinep1onediscon": "160",
    "param-scanlinep1twodiscon": "59",
    "param-scanlinep2": "190",
    "param-scanlinep2onediscon": "507",
    "param-scanlinep2twodiscon": "493",
    "param-secondpeakdelta": "647",
    "param-texturecountthresh": "0",
    "param-texturedifferencethresh": "1722",
    "param-usersm": "1",
    "param-zunits": "1000",
    "stream-depth-format": "Z16",
    "stream-fps": "30",
    "stream-height": "480",
    "stream-ir-format": "R8L8",
    "stream-width": "640"
}