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Model Explorer Overlays#

heliaPROFILER exports per-layer profiling metrics as JSON overlays compatible with Model Explorer. This lets you visually inspect which operators are hot spots.

How it works#

After profiling, overlay files are written to the model_explorer/ subfolder:

results/
├── summary.json
├── profile_results.csv
└── model_explorer/
    ├── me_overlay_ARM_PMU_CPU_CYCLES.json
    ├── me_overlay_ARM_PMU_INST_RETIRED.json
    ├── me_overlay_ARM_PMU_L1D_CACHE.json
    ├── me_overlay_ARM_PMU_MVE_INST_RETIRED.json
    └── ...

Each overlay maps graph node IDs to a numeric value with a gradient color palette (green → yellow → red). One overlay file is generated per PMU counter.

Using with Model Explorer#

  1. Open Model Explorer
  2. Load your .tflite model
  3. Click Add Overlay and select one of the me_overlay_*.json files
  4. Nodes are colored by the counter value — red = highest, green = lowest

Node ID matching

For heliaRT models, nodes are matched by sequential operator index (0, 1, 2, ...). For heliaAOT, nodes use the original TFLite operator index preserved through AOT compilation (e.g. the 3 in CONV_2D:3).

Disabling#

If you don't need overlays, disable them to skip file generation:

hpx profile model.tflite --no-model-explorer

output:
  model_explorer: false

Gradient palette#

Overlays use a 5-stop gradient for value visualization:

Value range Color
Minimum Green
25th percentile Light green
50th percentile Yellow
75th percentile Orange
Maximum Red

Zero-value nodes are rendered in neutral gray.