This module unwraps images taken through a panoramic lens. The unwrapped image is returned to the video thread or available as pano_unwrapped_image.
The user should specify the region of interest (the part of the raw image that should be unwrapped) by setting the following values:
Optionally, the image can be derotated to cancel the pitch and roll movements of the drone. This requires a correct setting of the vertical_resolution. Reasonable values can be found by looking at the unwrapped and derotated image and adjusting the vertical resolution until the environment no longer appears to move during pitch and roll motions.
Add to your firmware section: This example contains all possible configuration options, not all of them are mandatory!
These initialization functions are called once on startup.
<!DOCTYPE module SYSTEM "module.dtd">
<module name="pano_unwrap">
<doc>
<description>
Unwrap images taken through a panoramic lens
@image html images/airborne/modules/pano_unwrap/pano_unwrap.jpg "Left: AR.Drone 2.0 with Kogeto Dot 360 panoramic lens on bottom camera. Middle: raw image and region of interest (blue). Right: unwrapped image."
This module unwraps images taken through a panoramic lens. The unwrapped
image is returned to the video thread or available as
`pano_unwrapped_image`.
The user should specify the region of interest (the part of the raw image
that should be unwrapped) by setting the following values:
- The center of the lens (`center_x` and `center_y`)
- The radii of the top and bottom of the ROI (`radius_bottom` and
`radius_top`)
- The body +x direction in the raw image (`forward_direction`)
- The body +y direction in the raw image (`flip_horizontal`)
The region of interest can be shown by setting `show_calibration` to TRUE
and `overwrite_video` to FALSE.
The size of the output image can be set with `width` and `height`. The
height of the image can also be set to zero, in which case it is determined
automatically from the `vertical_resolution`.
Optionally, the image can be derotated to cancel the pitch and roll
movements of the drone. This requires a correct setting of the
`vertical_resolution`. Reasonable values can be found by looking at the
unwrapped and derotated image and adjusting the vertical resolution until
the environment no longer appears to move during pitch and roll motions.
The following assumptions are made:
- The vertical resolution is constant throughout the region of interest.
- Pitch and roll angles are small (for derotation).
@image html images/airborne/modules/pano_unwrap/unwrapped_derotated.png "Derotation (shown for large roll angle)."
</description>
<define name="PANO_UNWRAP_CAMERA" value="front_camera|bottom_camera (default)" description="Camera to use"/>
<define name="PANO_UNWRAP_CENTER_X" value="0.50" description="Center of lens in raw image [fraction of raw image width]"/>
<define name="PANO_UNWRAP_CENTER_Y" value="0.50" description="Center of lens in raw image [fraction of raw image height]"/>
<define name="PANO_UNWRAP_RADIUS_BOTTOM" value="0.20" description="Distance from the lens center to the bottom of the region of interest [fraction of raw image height]"/>
<define name="PANO_UNWRAP_RADIUS_TOP" value="0.30" description="Distance from lens center to the top of the region of interest [fraction of raw image height]"/>
<define name="PANO_UNWRAP_FORWARD_DIRECTION" value="270.0" description="Forward direction in raw image measured counterclockwise from right [deg]"/>
<define name="PANO_UNWRAP_FLIP_HORIZONTAL" value="TRUE|FALSE (default)" description="Flip output image horizontally"/>
<define name="PANO_UNWRAP_VERTICAL_RESOLUTION" value="0.18" description="Vertical resolution of region of interest [fraction of raw image height/rad]"/>
<define name="PANO_UNWRAP_DEROTATE_ATTITUDE" value="TRUE|FALSE (default)" description="Derotate the image, i.e. keep the panorama aligned with the horizon"/>
<define name="PANO_UNWRAP_WIDTH" value="640" description="Width of the unwrapped image [px]"/>
<define name="PANO_UNWRAP_HEIGHT" value="0" description="Height of the unwrapped image [px]. Set to 0 to determine automatically."/>
<define name="PANO_UNWRAP_OVERWRITE_VIDEO_THREAD" value="TRUE (default)|FALSE" description="Write unwrapped image to the video thread"/>
<define name="PANO_UNWRAP_FPS" value="0" description="Maximum FPS (0: unlimited)"/>
</doc>
<settings>
<dl_settings>
<dl_settings name="pano_unwrap">
<dl_setting shortname="center_x" var="pano_unwrap.center.x" min="0.0" step="0.01" max="1.0"/>
<dl_setting shortname="center_y" var="pano_unwrap.center.y" min="0.0" step="0.01" max="1.0"/>
<dl_setting shortname="radius_bottom" var="pano_unwrap.radius_bottom" min="0.0" step="0.01" max="1.0"/>
<dl_setting shortname="radius_top" var="pano_unwrap.radius_top" min="0.0" step="0.01" max="1.0"/>
<dl_setting shortname="forward_direction" var="pano_unwrap.forward_direction" min="0" step="1" max="360"/>
<dl_setting shortname="flip_hor" var="pano_unwrap.flip_horizontal" type="uint8" values="FALSE|TRUE" min="0" step="1" max="1"/>
<dl_setting shortname="v_resolution" var="pano_unwrap.vertical_resolution" min="-0.2" step="0.01" max="0.2"/>
<dl_setting shortname="derotate" var="pano_unwrap.derotate_attitude" type="uint8" values="FALSE|TRUE" min="0" step="1" max="1"/>
<dl_setting shortname="width" var="pano_unwrap.width" min="1" step="1" max="1920"/>
<dl_setting shortname="height" var="pano_unwrap.height" min="0" step="1" max="1080"/>
<dl_setting shortname="overwrite_video" var="pano_unwrap.overwrite_video_thread" type="uint8" values="FALSE|TRUE" min="0" step="1" max="1"/>
<dl_setting shortname="show_calibration" var="pano_unwrap.show_calibration" type="uint8" values="FALSE|TRUE" min="0" step="1" max="1"/>
</dl_settings>
</dl_settings>
</settings>
<depends>video_thread</depends>
<header>
<file name="pano_unwrap.h"/>
</header>
<init fun="pano_unwrap_init()"/>
<makefile>
<file name="pano_unwrap.c"/>
<define name="CV_ALLOW_VIDEO_TO_CHANGE_SIZE" value="1"/>
</makefile>
</module>
1.8.8