How to adjust segment parameter to segment anything?

I segment a png ,i use code as follow:

mask_generator_2 = SAM2AutomaticMaskGenerator(
model=sam2,
points_per_side=64,
points_per_batch=128,
pred_iou_thresh=0.7,
stability_score_thresh=0.92,
stability_score_offset=0.7,
crop_n_layers=1,
box_nms_thresh=0.7,
crop_n_points_downscale_factor=2,
min_mask_region_area=25.0,
use_m2m=True,
)

and i get the result as follow:

i found i can not segment anything, and someone can help me ,how to adjust SAM2AutomaticMaskGenerator parameters to segement anything,thanks