Skip to content

Possible bug in detection locations #19

Description

@a64bit

Hi,

I am trying to use the trained models given by the authors. However, I discovered that the detection output locations are wrong and in many cases outside the image range!

To further investigate about this, I used the detection code in examples , and compared the results from the original SSD implementation of Wei and the new SSD model with ResNet101 introduced here. I tested the same image proposed in the examples (examples/images/fish-bike.jpg).

With the old SSD code with VGG model I get right results as follows:
[0.028087676, 0.23656183, 0.88743579, 0.95228869, 2, 0.82035357, u'bicycle']
[0.42205709, 0.026113272, 0.70970505, 0.51584023, 15, 0.99626094, u'person']

But with the new SSD model in this repository I get:
[3.6806207, 3.2651825, 3.9601259, 3.7642479, 1, 0.99327165, u'person']
[1.065011, 0.64031565, 1.3344085, 1.142953, 1, 0.9836536, u'person']
[255.99077, 256.33829, 256.99084, 256.97342, 2, 0.7926603, u'bicycle']
[14.477366, 14.709455, 15.462966, 15.438332, 2, 0.69000566, u'bicycle']

The first 4 numbers are the normalized detection locations [x_min, y_min, x_max, y_max], so after multiplying by the image width and height (481 and 323 in this case), I should get the bbox locations inside the tested image. This is the case with the original SSD models, as I get the right locations:
[14, 76, 427, 308]
[203, 8, 341, 167]

but with the new SSD-ResNet model introduced here, I get the locations:
[1770, 1055, 1905, 1216]
[512, 207, 642, 369]
[123132, 82797, 123613, 83002]
[6964, 4751, 7438, 4987]

which introduce bboxes outside the image! It is also obvious problem since the normalized positions should not exceed 1.0. Note that the same problem happens when using the DSSD model.

Thank you.

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions