# Why py-faster-rcnn has 0 detection in trained model with no pretrained weight?

I tested py-faster-rcnn and found that if I don't use pretrained weight then mAP is 0 in testing.

I hope that I should see some value eventhough not very high.

With pretrained model, mAP was above 99%.

Why so difference and how can I solve the issue?

With pretrained weight

AP for vertical = 1.0000
AP for horizontal = 0.9500
AP for plate = 1.0000
Mean AP = 0.9833
~~~~~~~~
Results:
1.000
0.950
1.000
0.983
~~~~~~~~


Without pretrained weight,

AP for vertical = 0.0001
AP for horizontal = 0.0000
AP for plate = 0.0000
Mean AP = 0.0000
~~~~~~~~
Results:
0.000
0.000
0.000
0.000
~~~~~~~~

• I changed the convolution layers with xavier weight initialization. I saw some improvements. But not significant. – batuman Dec 6 '18 at 1:47

## 1 Answer

I have tested with all weight initializations and xavier is the best. We need to initialize weights if not the network doesn't converge.