## repository: https://github.com/danielsnider/image_overlay_compass_and_scale
<<PackageHeader(image_overlay_scale_and_compass)>>

<<TOC>>

== Overview ==
Add an indication of scale and compass to images and video streams.

{{attachment:mars.png|Overlay|width="500"}}

This package uses OpenCV’s python library to overlay text and overlay, resize, rotate, and warp images.

== Quick Start ==
1. Install:

{{{
$ sudo apt-get install ros-kinetic-image-overlay-compass-and-scale
}}}
2. Launch node:

{{{
$ roslaunch image_overlay_compass_and_scale overlay.launch
}}}

3. Publish heading and scale values

{{{
$ rostopic pub /heading std_msgs/Float32 45 # unit is degrees
$ rostopic pub /scale std_msgs/Float32 133 # unit is centimeters 
}}}

4. View resulting image

{{{
$ rqt_image_view /overlay/compressed
}}}

== Command Line Interface (CLI) ==

Invoke once using the Command Line Interface (CLI) to save the image overlay to disk instead of publishing to ROS.

{{{
$ roscd image_overlay_compass_and_scale
$ ./src/image_overlay_compass_and_scale/image_overlay.py --input-image ~/mars.png --heading 45 --scale-text 133 --output-file output.png
}}}

=== CLI Options ===
{{{
Usage: image_overlay.py [OPTIONS]

Options:
--input-image TEXT  Path to input image file  [required]
--heading FLOAT     Current heading relative to north in degrees  [required]
--scale-text FLOAT  The value to be displayed on the right of the scale bar
                    in centimeters  [required]
--output-file TEXT  Output filename to save result to
                    [default='output.png']
--help              Show this message and exit.
}}}

== Nodes ==
{{{
#!clearsilver CS/NodeAPI
name = image_overlay_compass_and_scale
pub {
  0.name = overlay/compressed
  0.type = sensor_msgs/CompressedImage
  0.desc = The resulting image overlaid with scale and compass indicators.
  }
sub {
  0.name = camera/compressed
  0.type = sensor_msgs/CompressedImage
  0.desc = Image topic that will be overlaid with with scale and compass indicators.
  1.name = heading
  1.type = std_msgs/Float32
  1.desc = Current heading relative to north in degrees.
  2.name = scale
  2.type = std_msgs/Float32
  2.desc = The value to be displayed on the right of the scale bar in centimeters.
}
param {
  0.name = ~framerate
  0.type = int
  0.desc = The rate at which to publish an image overlaid with scale and compass indicators.
  0.default = 3
}
}}}

== Use Case ==
=== Use in the University Rover Competition (URC) ===
This functionality is needed for the University Rover Competition (URC) and we hope this helps you.

== What to expect when nothing is received by the node ==
{{attachment:default.png|Overlay|width="500"}}