Possible bug/issue in using AI assisted segmentation

Describe Your Question

I am trying out the segmentation demo using the latest OHIF viewer release. I load the CTA Head and Neck Study in segmentation mode (second study listed in the study list). Then I add a new segmentation and try to use the “Marker Guided Label Map” tool from the segmentation toolbar. As soon as I click the button there are several errors. I believe it tries to load the Segment Anything Model (SAM) model from hugging face. I believe it tries to load the model in FP16 quantized mode which leads to a string of errors but I think they all stem from using FP16 format somewhere in the model load pipeline.

I have RTX 3090 and RTX 4090 GPUs which support FP16 format so that’s not an issue. I had to enable several flags related to using web gpu in chrome to even get to this point (enable-unsafe-gpu, vulkan etc). I can share GPU report from chrome if needed.

This same issue also happens when I try to run the Cornerstone3D “Segmentation AI Assisted” example found here “samclientside”

What steps can we follow to reproduce the bug?

  1. Navigate to OHIF viewer website ohif dot org
  2. Click Try it Now
  3. Open Second study (CTA Head and Neck) in the list in Segmentation mode
  4. Click Add Segmentation
  5. Click “Marker Guided Label Map” tool from the right side segmentation tool box
  6. See errors in the browser console.

A string of these errors"
``2025-04-20 14:26:54.225700 [W:onnxruntime:, constant_folding.cc:269 ApplyImpl] Could not find a CPU kernel and hence can’t constant fold Div node ‘/image_encoder/blocks.0/attn/Div_1’

Followed by:
```status sam-b-decoder (cached)```

Followed by:
```An uncaught WebGPU validation error was raised: Error while parsing WGSL: :8:68 error: 'f16' type used without 'f16' extension enabled
        @group(0) @binding(0) var<storage, read> aData: array<vec4<f16>>;
                                                                   ^^^


 - While validating [ShaderModuleDescriptor ""Div""]
 - While calling [Device].CreateShaderModule([ShaderModuleDescriptor ""Div""]).

Finally a string of these for every MUL, DIV etc operations:

Error while parsing WGSL: :8:68 error: 'f16' type used without 'f16' extension enabled
        @group(0) @binding(0) var<storage, read> aData: array<vec4<f16>>;
                                                                   ^^^


 - While validating [ShaderModuleDescriptor ""Div""]
 - While calling [Device].CreateShaderModule([ShaderModuleDescriptor ""Div""]).

Compilation log for [Invalid ShaderModule "Div"]:
1 error(s) generated while compiling the shader:
:8:68 error: 'f16' type used without 'f16' extension enabled
        @group(0) @binding(0) var<storage, read> aData: array<vec4<f16>>;