!10941 fix centernet data preprocess is slow

From: @caojian05
Reviewed-by: @wuxuejian,@oacjiewen
Signed-off-by: @wuxuejian

model_zoo/research/cv/centernet/src/dataset.py

@@ -32,6 +32,7 @@ from src.image import gaussian_radius, draw_umich_gaussian, draw_msra_gaussian,
 from src.visual import visual_image
 
 _current_dir = os.path.dirname(os.path.realpath(__file__))
+cv2.setNumThreads(0)
 
 
 class COCOHP(ds.Dataset):