Possibly by using OpenMP or manually, as the data blocks are usually independent of each other.
Thread 1: RGRGRGRGRG...
GBGBGBGBGBExample for processing done by 2 threads (same data array "split" in half):
Thread 1:
RGRGRGRGRG...
GBGBGBGBGB...
...
Thread 2: RGRGRGRGRG...
RGRGRGRGRG...
GBGBGBGBGB...
...