Add color space output for rgb/hsl/hsv color filters

[k-okada]

Enable to publish color space during filtering
@tongtybj, @chibi314 could you check this node with your example?

rgb space

hls space

hsv space

roslaunch opencv_apps hsv_color_filter.launch image:=/camera/rgb/image_color

Discussions

• we publish color space by PointCloud2, is it ok? if we use PointCloud2, we need to set frame_id (currently it is map) and define scales (1 for now)
• Should we publish threshold? One idea is to publish threshold planes, other is publish point within threshold with colored and publish outlier points with gray scale

==

input image

rgb space

hls space

hsv space

https://gist.github.com/k-okada/5c7531cecc5c04abff0674afe35eba06

[tongtybj]

I tested the data in 柏 while flying towards to target tree.

RGB space

HLS spce

HSV space

I am not familiar with the format of point cloud.
And I prefer threshold plane, because we can see the change directly while tuning the filtering parameters from cfg

[k-okada]

very nice example, how about 233500f, this outputs with gray if the point is not within the threshold

[tongtybj]

I tried with the same rosbag. LVGTM!

RGB space

HLS space

HSV space