add util file

Author: Clément Pinard

util.py

@@ -0,0 +1,47 @@
+import os
+import numpy as np
+import shutil
+import torch
+
+
+def save_checkpoint(state, is_best, save_path, filename='checkpoint.pth.tar'):
+    torch.save(state, os.path.join(save_path,filename))
+    if is_best:
+        shutil.copyfile(os.path.join(save_path,filename), os.path.join(save_path,'model_best.pth.tar'))
+
+
+class AverageMeter(object):
+    """Computes and stores the average and current value"""
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.val = 0
+        self.avg = 0
+        self.sum = 0
+        self.count = 0
+
+    def update(self, val, n=1):
+        self.val = val
+        self.sum += val * n
+        self.count += n
+        self.avg = self.sum / self.count
+
+    def __repr__(self):
+        return '{:.3f} ({:.3f})'.format(self.val, self.avg)
+
+
+def flow2rgb(flow_map, max_value):
+    flow_map_np = flow_map.detach().cpu().numpy()
+    _, h, w = flow_map_np.shape
+    flow_map_np[:,(flow_map_np[0] == 0) & (flow_map_np[1] == 0)] = float('nan')
+    rgb_map = np.ones((3,h,w)).astype(np.float32)
+    if max_value is not None:
+        normalized_flow_map = flow_map_np / max_value
+    else:
+        normalized_flow_map = flow_map_np / (np.abs(flow_map_np).max())
+    rgb_map[0] += normalized_flow_map[0]
+    rgb_map[1] -= 0.5*(normalized_flow_map[0] + normalized_flow_map[1])
+    rgb_map[2] += normalized_flow_map[1]
+    return rgb_map.clip(0,1)