In short: The new feature of ICC profile v4 is useless for you.

In long:

I don’t mean to say anything bad about ICC, but I guess you have a common knowledge about a technical committee. A technical committee never makes a new big thing. It always gathers existing success stories and joins them together by compromise. Sometimes it works fine, for example, the programming language Java. Sometimes it makes garbage, for example, W3C/IETF often did. The garbage is an elaborate intellectual achievement, but it just makes insubstantial fruit from substantial labor.

What is the difference between them? The existing success stories. When there are no existing success stories available, a technical committee makes do with garbage. This is an universal law of a technical committee.

Rendering Intent: Perceptual is a no success story land

This document of Windows Color System tells us a fact; The guy couldn’t find a good algorithm for perceptual rendering intent in existing articles.

A few algorithms (gamut mapping algorithm: GMA) are proposed after Windows Color System. But no one becomes dominant in my eyes. It is hard to make money from superior GMA, but most scientific problems are the same. My opinion; Everyone is a loser in this GMA land.

Another sign of no-existing-success-story is ICC profile v4’s Perceptual Reference Medium Gamut (PRMG). If there is a successful and dominant GMA, ICC should just name it instead of PRMG. ICC can require color management modules to implement the dominant GMA if there is such a thing. PRMG is a sign of perfunctory, and it is garbage too.

PRMG is a streetlight

There is a famous anecdote:

A policeman sees a drunk man searching for something under a streetlight and asks what the drunk has lost. He says he lost his keys and they both look under the streetlight together. After a few minutes the policeman asks if he is sure he lost them here, and the drunk replies, no, and that he lost them in the park. The policeman asks why he is searching here, and the drunk replies, “this is where the light is”.

ICC was much cleverer than the drunk man. ICC built a streetlight, PRMG. And cleverer, in some common cases, the key is there. A few articles describe such cases. In most cases, the key isn’t there.

Except for PRMG, there is no substantial new feature for printing in ICC profile v4. So I decided to adopt ICC profile v2, not v4.