[jsk_perception] Add invert_mask_image nodelet

[iory]

What is this?

This is PR for #2706 .

InvertMaskImage

Inverts the input mask image.

Subscribing Topic

• ~input (sensor_msgs/Image)

  Input mask image.

Publishing Topic

• ~output (sensor_msgs/Image)

  Inverted mask image.

Parameters

• ~queue_size (Int, default: 1)

  How many messages you allow about the subscriber to keep in the queue.

Sample

roslaunch jsk_perception sample_invert_mask_image.launch

[Affonso-Gui]

Nice! I will test as soon as I can.

[k-okada]

can we achieve this by http://wiki.ros.org/opencv_apps#adding_images with image1 * -1 + (dummy image 2) * 0 + (offset ??) ??? -- ◉ Kei Okada 2022年9月17日(土) 0:31 Affonso, Guilherme ***@***.***>:

…

Nice! I will test as soon as I can. — Reply to this email directly, view it on GitHub <#2726 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AADYNXB6GA3FP5JBPS3YFCLV6SHANANCNFSM6AAAAAAQOJ5ZLY> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[Affonso-Gui]

Sorry for the delay. Works perfectly!

The sample is a bit too complicated for my taste but works great as well.

@k-okada The opencv_apps adding_images didn't work for me. It seems like the offset is only added after the image has already been zeroed out.
What does serve as a work around is using the negative flag in ApplyMaskImage.

  <node name="invert_lmask"
        pkg="nodelet" type="nodelet"
        args="load jsk_perception/ApplyMaskImage $(arg MANAGER)">
    <remap from="~input" to="$(arg INPUT_IMAGE)" />
    <remap from="~input/mask" to="/robot/left/mask" />
    <remap from="~output/mask" to="/robot/left/mask_inverted" />
    <rosparam>
      negative: true
      clip: false
    </rosparam>
  </node>

However, I think having this as a dedicated node is better both for efficiency and understandability.