I was able to linear blend the beamwidth with the 2D occupancy grid map by resizing the beamwidth to the size of the 2D occupancy grid map, transform the beamwidth corresponding to the camera's pose and blending the two images as the requirement of the function is to have both images the same size.
However, it blurs the entire map even with an alpha of 0.9
Is it possible to apply linear blend only the portion of the map that the beamwidth (triangle) covers? How?