# Access to UNet encoder backbone in Metalhead

**URL:** <https://discourse.julialang.org/t/access-to-unet-encoder-backbone-in-metalhead/132375>\
**Category:** General Usage\
**Tags:** metalhead, unet\
**Created:** [September 14, 2025, 7:23pm UTC](https://discourse.julialang.org/t/access-to-unet-encoder-backbone-in-metalhead/132375 "2025-09-14T19:23:26Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![cirobr](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/cirobr/32/219994_2.png) [@cirobr](https://discourse.julialang.org/u/cirobr)\
**Post date:** [September 14, 2025, 7:23pm UTC](https://discourse.julialang.org/t/access-to-unet-encoder-backbone-in-metalhead/132375/1 "2025-09-14T19:23:26Z")

</div>

Cheers,

In Metalhead, consider the following model:

```julia-auto
bb = backbone( ResNet(50) )
model = UNet((256,256), 3, 10, bb)

```

Need to get access to a specific activation map from the model’s encoder (actually, to a specific activation map in the ResNet backbone). The activation map is easily accessible by choosing the appropriate layer from the “bb” variable, but apparently not from “model”, as Metalhead’s function backbone() seems not to work for the UNet.

Thanks in advance.