Under Web Services there is a conversion palette. One of the functions here is to convert LV Image data to a PNG stream. This is super useful when dealing with sending and receiving large amounts of PNG data over something like websockets. I've used this in places where a web page can control a VI, and the image of some front panel controls can be sent to the web page.
However only recently did I realize this function turns the image into a PNG stream that is completely uncompressed. This idea is to expose the Compression input to the VI. Here is just one example where I get the image of a control then represent it as a PNG. With no compression this file is over 64KB. With just the most minimum compression that drops to 3KB, and down to 2KB under the highest compression.