Updates to support autocnet graph writing

.travis.yml

@@ -44,7 +44,7 @@ install:
   - conda config --add channels conda-forge
   - conda config --add channels jlaura
   - conda install -c conda-forge gdal h5py
-  - conda install pandas sqlalchemy pyyaml
+  - conda install pandas sqlalchemy pyyaml networkx
   - conda install -c jlaura pvl protobuf
 
   # Development installation

appveyor.yml

@@ -53,7 +53,7 @@ install:
     - cmd: conda config --add channels conda-forge
     - cmd: conda config --add channels jlaura
     - cmd: conda install --yes -c conda-forge gdal h5py
-    - cmd: conda install --yes pandas sqlalchemy pyyaml
+    - cmd: conda install --yes pandas sqlalchemy pyyaml networkx
     - cmd: conda install --yes -c jlaura protobuf pvl
 
     # Development installation

environment.yml

@@ -10,3 +10,4 @@ dependencies:
   - pandas
   - sqlalchemy
   - pyyaml
+  - networkx

plio/io/io_autocnetgraph.py

+from io import BytesIO
+import json
+import os
+import warnings
+from zipfile import ZipFile
+
+from networkx.readwrite import json_graph
+import numpy as np
+import pandas as pd
+
+
+try:
+    import autocnet
+    autocnet_avail = True
+except:
+    autocnet_avail = False
+
+class NumpyEncoder(json.JSONEncoder):
+    def default(self, obj):
+        """If input object is an ndarray it will be converted into a dict
+        holding dtype, shape and the data, base64 encoded.
+        """
+        if isinstance(obj, np.ndarray):
+            return dict(__ndarray__= obj.tolist(),
+                        dtype=str(obj.dtype),
+                        shape=obj.shape)
+        # Let the base class default method raise the TypeError
+        return json.JSONEncoder.default(self, obj)
+
+def save(network, projectname):
+    """
+    Save an AutoCNet candiate graph to disk in a compressed file.  The
+    graph adjacency structure is stored as human readable JSON and all
+    potentially large numpy arrays are stored as compressed binary. The
+    project archive is a standard .zip file that can have any ending,
+    e.g., <projectname>.project, <projectname>.zip, <projectname>.myname.
+
+    TODO: This func. writes a intermediary .npz to disk when saving.  Can
+    we write the .npz to memory?
+
+    Parameters
+    ----------
+    network : object
+              The AutoCNet Candidate Graph object
+
+    projectname : str
+                  The PATH to the output file.
+    """
+    # Convert the graph into json format
+    js = json_graph.node_link_data(network)
+
+    with ZipFile(projectname, 'w') as pzip:
+        js_str = json.dumps(js, cls=NumpyEncoder, sort_keys=True, indent=4)
+        pzip.writestr('graph.json', js_str)
+
+        # Write the array node_attributes to hdf
+        for n, data in network.nodes_iter(data=True):
+            grp = data['node_id']
+            np.savez('{}.npz'.format(data['node_id']),
+                     descriptors=data.descriptors,
+                     _keypoints=data._keypoints,
+                     _keypoints_idx=data._keypoints.index,
+                     _keypoints_columns=data._keypoints.columns)
+            pzip.write('{}.npz'.format(data['node_id']))
+            os.remove('{}.npz'.format(data['node_id']))
+
+        # Write the array edge attributes to hdf
+        for s, d, data in network.edges_iter(data=True):
+            if s > d:
+                s, d = d, s
+            grp = str((s,d))
+            np.savez('{}_{}.npz'.format(s, d),
+                     matches=data.matches,
+                     matches_idx=data.matches.index,
+                     matches_columns=data.matches.columns,
+                     _masks=data._masks,
+                     _masks_idx=data._masks.index,
+                     _masks_columns=data._masks.columns)
+            pzip.write('{}_{}.npz'.format(s, d))
+            os.remove('{}_{}.npz'.format(s, d))
+
+def json_numpy_obj_hook(dct):
+    """Decodes a previously encoded numpy ndarray with proper shape and dtype.
+
+    :param dct: (dict) json encoded ndarray
+    :return: (ndarray) if input was an encoded ndarray
+    """
+    if isinstance(dct, dict) and '__ndarray__' in dct:
+        data = np.asarray(dct['__ndarray__'])
+        return np.frombuffer(data, dct['dtype']).reshape(dct['shape'])
+    return dct
+
+def load(projectname):
+    if autocnet_avail is False:
+        warning.warn('AutoCNet Library is not available.  Unable to load an AutoCNet CandidateGraph')
+        return
+
+    with ZipFile(projectname, 'r') as pzip:
+        # Read the graph object
+        with pzip.open('graph.json', 'r') as g:
+            data = json.loads(g.read().decode(),object_hook=json_numpy_obj_hook)
+
+        cg = autocnet.graph.network.CandidateGraph()
+        Edge = autocnet.graph.edge.Edge
+        Node = autocnet.graph.node.Node
+        # Reload the graph attributes
+        cg.graph = data['graph']
+        # Handle nodes
+        for d in data['nodes']:
+            n = Node(image_name=d['image_name'], image_path=d['image_path'], node_id=d['id'])
+            n['hash'] = d['hash']
+            # Load the byte stream for the nested npz file into memory and then unpack
+            nzf = np.load(BytesIO(pzip.read('{}.npz'.format(d['id']))))
+            n._keypoints = pd.DataFrame(nzf['_keypoints'], index=nzf['_keypoints_idx'], columns=nzf['_keypoints_columns'])
+            n.descriptors = nzf['descriptors']
+            cg.add_node(d['node_id'])
+            cg.node[d['node_id']] = n
+        for e in data['links']:
+            cg.add_edge(e['source'], e['target'])
+            edge = Edge()
+            edge.source = cg.node[e['source']]
+            edge.destination = cg.node[e['target']]
+            edge['fundamental_matrix'] = e['fundamental_matrix']
+            edge['weight'] = e['weight']
+            nzf = np.load(BytesIO(pzip.read('{}_{}.npz'.format(e['source'], e['target']))))
+
+            edge._masks = pd.DataFrame(nzf['_masks'], index=nzf['_masks_idx'], columns=nzf['_masks_columns'])
+            edge.matches = pd.DataFrame(nzf['matches'], index=nzf['matches_idx'], columns=nzf['matches_columns'])
+            # Add a mock edge
+            cg.edge[e['source']][e['target']] = edge
+
+    return cg