With the advent of inverse lithography technology, the landscape of electron beam lithography has undergone a paradigm shift, transitioning from a single variable-shaped beam to a multi-beam writer. Conversely, in the realm of mask process correction (MPC), the majority of techniques continue to depend on the manipulation of figures and edges to adjust shape boundaries. We have developed a MPC system that is integrated within the multi-beam writer. This system leverages the rasterized pixel data for exposure, which is conventionally accessible within the writer itself. We describe how our inline MPC works in the pixel domain instead of geometry domain to improve pattern fidelity of curvilinear shapes without additional turnaround time.