Fix ssd bug (#1288)

* fix bug of ssd

* clean

configs/ssd512_coco.py

@@ -65,7 +65,7 @@ train_pipeline = [
         type='MinIoURandomCrop',
         min_ious=(0.1, 0.3, 0.5, 0.7, 0.9),
         min_crop_size=0.3),
-    dict(type='Resize', img_scale=(300, 300), keep_ratio=False),
+    dict(type='Resize', img_scale=(512, 512), keep_ratio=False),
     dict(type='Normalize', **img_norm_cfg),
     dict(type='RandomFlip', flip_ratio=0.5),
     dict(type='DefaultFormatBundle'),
@@ -75,7 +75,7 @@ test_pipeline = [
     dict(type='LoadImageFromFile'),
     dict(
         type='MultiScaleFlipAug',
-        img_scale=(300, 300),
+        img_scale=(512, 512),
         flip=False,
         transforms=[
             dict(type='Resize', keep_ratio=False),

mmdet/datasets/pipelines/transforms.py

@@ -527,7 +527,7 @@ class Expand(object):
         left = int(random.uniform(0, w * ratio - w))
         top = int(random.uniform(0, h * ratio - h))
         expand_img[top:top + h, left:left + w] = img
-        boxes = boxes + np.tile((left, top), 2)
+        boxes = boxes + np.tile((left, top), 2).astype(boxes.dtype)
 
         results['img'] = expand_img
         results['gt_bboxes'] = boxes