rosbridge vs rosboard

[Hao-Starrr]

Hi~ Thank you for your work.
I am recently searching for the solution that communicate ROS via websocket. As you mentioned, rosbridge and rosboard are competitors.
As your result shows:

Streaming Tool Avg. Latency [ms] Avg. Bandwidth Usage [KiB/s]
Rosboard (JPEG compression) 96.38 11010.14
Rosbridge (no compression) 22330.06 12420.32
Rosbridge (CBOR compression) 6035.99 8215.36
Rosbridge (PNG compression) 19096.12 12054.46

I am wondering, does this different occur by the compression algorithm or the implementation of server? How about if i use JPEG compression on Rosbridge?

Thank you.