Fastest way to send an image over Redis

I am working on the Edge platform Jetson Xavier NX. A have two applications running C++ and Python and I am using Redis for real time communication between the two. I have to send one image from C++ to Python and later back again from Python to C++. Which is the fastest way to do so?

The options I tried are:

  1. Save the image as a PNG file and publish the file path which is then subscribed by Python application and then the image is read. This takes about 0.4 seconds
  2. Convert the image to bytes format and set this as a “Value” in Key-Value pair and use the same Key in Python to read the bytes and then convert it back to an image. This takes about 0.5 seconds.

I want something much faster. Are there any other ways ?

How big are the images? Maybe you could just send them over Pub Sub and skip the disk altogether?