ImportError: cannot import name 'BinaryImage' from 'perception'

[littlefiveRobot]

(pointnetgpd) klxue@dell-XPS:~/code/PointNetGPD/apps$ python generate-dataset-canny.py
WARNING:root:autolab_core not installed as catkin package, RigidTransform ros methods will be unavailable
Traceback (most recent call last):
File "generate-dataset-canny.py", line 13, in
from dexnet.grasping.quality import PointGraspMetrics3D
File "/home/klxue/code/dex-net/src/dexnet/init.py", line 24, in
from dexnet.api import DexNet
File "/home/klxue/code/dex-net/src/dexnet/api.py", line 42, in
import dexnet.database.database as db
File "/home/klxue/code/dex-net/src/dexnet/database/init.py", line 22, in
from dexnet.database.hdf5_factory import Hdf5ObjectFactory
File "/home/klxue/code/dex-net/src/dexnet/database/hdf5_factory.py", line 32, in
import meshpy.mesh as mesh
File "/home/klxue/code/meshpy/meshpy/init.py", line 2, in
from meshpy.image_converter import ImageToMeshConverter
File "/home/klxue/code/meshpy/meshpy/image_converter.py", line 19, in
from perception import BinaryImage
ImportError: cannot import name 'BinaryImage' from 'perception' (/home/klxue/anaconda3/envs/pointnetgpd/lib/python3.7/site-packages/perception/init.py)

[littlefiveRobot]

hello, I encountered some questions when I generated dataset . Could you help me？ Thanks.
I did not install ros bag about camera mentioned in your readme file in step 2 and I had downloaded ycb-dateset like this：
|ycb_meshes_google
|objects
├002_master_chef_can
|└── google_512k
| ├── kinbody.xml (no use)
| ├── nontextured.obj
| ├── nontextured.ply
| ├── nontextured.sdf (generated by SDFGen)
| ├── nontextured.stl
| ├── textured.dae (no use)
| ├── textured.mtl (no use)
| ├── textured.obj (no use)
| ├── textured.sdf (no use)
| └── texture_map.png (no use)
├003_cracker_box
└004_sugar_box
...