RV-9 pilot reported aborting takeoff when non communicating aircraft cross the runway resulted in a critical ground conflict.

Narrative

I had flown into ZZZ for a fuel and bathroom stop; on my way to ZZZ1. I had completed all tasks and was preparing to takeoff from Runway XX; which has a direct entry off of the ramp. I ensured the runway was clear; both from a final approach and takeoff perspective; and made appropriate radio calls on CTAF. No other radio traffic for ZZZ was noted.Of note is that ZZZ Airport is the staging airport for the ZZZZZ 2 ZZZ1 mass arrival; which was to take place the next day. The camping and staging area at the airport for the Cessnas is at the approach end of crossing Runway XY; on Taxiway 1. Taxiway 1 has an entry to/from the opposite end of the ramp and crosses Runway XZ/XX.On my takeoff roll from Runway XX; I observed the taxiing progress of a Cessna who had exited the ramp onto Taxiway 1; turned right; and presumably was going to cross Runway XZ/XX to make his way to the camping/staging area. I mentally noted he was not slowing his taxi speed as I accelerated to rotation speed. No crossing CTAF calls by the Cessna were made. Predicting he would continue on Taxiway 1; across Runway XX; I made a warning call on CTAF. The crossing Cessna did not stop; nor slow down. At this point I was at rotation speed; approximately 50kts. I immediately cut power and applied heavy breaking action; which safely slowed me to ground speed well before the crossing point. The Cessna; by this point; had crossed to the far side of Taxiway 1 and continued onward. I exited on the same Taxiway opposite direction; re-entered the ramp; and notified ramp personnel of the event in the hopes they could track down who just crossed to the camping area (I was unable to note the tail number as it happened). I then performed an uneventful second takeoff attempt from Runway XX.I do not believe the Cessna was aware of my radio calls; takeoff actions; or any other indication that I was occupying the runway as he taxied out from the ramp. At no point did he make crossing or clearing calls on CTAF.