batdetect2/docs/source/how_to/configure-spectrogram-preprocessing.md
2026-03-28 19:42:09 +00:00

60 lines
1.2 KiB
Markdown

# How to configure spectrogram preprocessing
Use this guide to set STFT, frequency range, and spectrogram transforms.
## 1) Configure STFT and frequency range
```yaml
preprocess:
stft:
window_duration: 0.002
window_overlap: 0.75
window_fn: hann
frequencies:
min_freq: 10000
max_freq: 120000
```
## 2) Configure spectrogram transforms
`spectrogram_transforms` are applied in order.
```yaml
preprocess:
spectrogram_transforms:
- name: pcen
time_constant: 0.4
gain: 0.98
bias: 2.0
power: 0.5
- name: spectral_mean_subtraction
- name: scale_amplitude
scale: db
```
Common built-ins:
- `pcen`
- `spectral_mean_subtraction`
- `scale_amplitude` (`db` or `power`)
- `peak_normalize`
## 3) Configure output size
```yaml
preprocess:
size:
height: 128
resize_factor: 0.5
```
## 4) Keep train and inference settings aligned
Use the same preprocessing setup for training and prediction whenever possible.
Large mismatches can degrade model performance.
## Related pages
- Why consistency matters: {doc}`../explanation/preprocessing-consistency`
- Preprocessing config reference: {doc}`../reference/preprocessing-config`