Refine import cocoapi (#143)

* refine cocoapi import

* fix infer when anno_path is None

ppdet/data/source/coco.py

@@ -14,7 +14,6 @@
 
 import os
 import numpy as np
-from pycocotools.coco import COCO
 
 from .dataset import DataSet
 from ppdet.core.workspace import register, serializable
@@ -75,6 +74,7 @@ class COCODataSet(DataSet):
 
         assert anno_path.endswith('.json'), \
             'invalid coco annotation file: ' + anno_path
+        from pycocotools.coco import COCO
         coco = COCO(anno_path)
         img_ids = coco.getImgIds()
         cat_ids = coco.getCatIds()

ppdet/data/source/dataset.py

@@ -75,6 +75,8 @@ class DataSet(object):
         return self.cname2cid
 
     def get_anno(self):
+        if self.anno_path is None:
+            return
         return os.path.join(self.dataset_dir, self.anno_path)
 
     def get_imid2path(self):

ppdet/utils/visualizer.py

@@ -18,7 +18,6 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 import numpy as np
-import pycocotools.mask as mask_util
 from PIL import Image, ImageDraw
 
 from .colormap import colormap
@@ -56,6 +55,7 @@ def draw_mask(image, im_id, segms, threshold, alpha=0.7):
         segm, score = dt['segmentation'], dt['score']
         if score < threshold:
             continue
+        import pycocotools.mask as mask_util
         mask = mask_util.decode(segm) * 255
         color_mask = color_list[mask_color_id % len(color_list), 0:3]
         mask_color_id += 1