mlgraham/species-classifier-fungi

Species classifier: fungi

Not for edibility decisions. This model names a fungus species from a photo with the accuracy below, which means a wrong top-1 answer about one time in four. Never eat a mushroom on the strength of a classifier's output.

A 341-species fungus classifier (mushrooms, brackets, puffballs, cup fungi and 55 lichens) small enough for microcontrollers and the Coral Edge TPU. MobileNetV2 at full width and 160 px, full-integer int8, trained on the iNaturalist 2021 competition data. Part of species-classifiers, which also rescues Google's AIY Vision Kit insect, plant and bird models into the same shape.

File	What it is
fungi_int8.tflite	3.1 MB, full-integer, uint8 in and out. Runs as is on TensorFlow Lite Micro (ESP32-S3, Coral Dev Board Micro CPU, Raspberry Pi) and phones through LiteRT
fungi_int8_edgetpu.tflite	the same model compiled with Edge TPU compiler 16.0, every op mapped, 3.16 MiB cached on-chip
fungi_float32.tflite	float in and out, for desktop use or your own quantization
fungi_int8_vela.tflite	the int8 model compiled with Arm's Vela for the Ethos-U55 in the Seeed Grove Vision AI V2, using Seeed's Himax configuration; upload it with SenseCraft AI's Model Assistant
labels.txt	one class per line, Latin name (Common name), line number = class index
classes.json	the full taxonomy per class (kingdom to species), for order and family roll-ups

Accuracy

Measured on the int8 file over the 3,410 iNaturalist 2021 validation images for these species (10 per species), with an 87.5% center crop:

Input	Top-1	Top-5
Color	74.0%	93.5%

The PyTorch checkpoint scores 74.4% top-1 under the same crop. This is the strongest model in the collection; many of these species have a distinctive shape and color, and 10 validation images per species is a small test, so expect lower numbers on your own photos. For comparison, Google's stock AIY insect model scores 59.1% top-1 on the iNat2021 species it shares, choosing among 1,022 classes.

Input contract

• Input [1, 160, 160, 3] uint8 RGB, 0 to 255, no normalization; the model rescales internally.
• Output [1, 341] uint8 probabilities, scale 1/256 and zero point 0, so prob = value / 256. No background class.
• Center-crop to a square. The model was validated with an 87.5% center crop (resize the short side to 183, crop 160), which is worth about half a point of top-1 over the whole frame.
• Ops are plain Conv2D, DepthwiseConv2D, Add, AveragePool, FullyConnected and Softmax, so the file converts for the Raspberry Pi AI Camera (IMX500) and Arm Ethos-U boards as well as the Edge TPU.

import numpy as np, tensorflow as tf
from PIL import Image

interp = tf.lite.Interpreter(model_path="fungi_int8.tflite"); interp.allocate_tensors()
inp, out = interp.get_input_details()[0], interp.get_output_details()[0]
labels = open("labels.txt").read().splitlines()

img = Image.open("photo.jpg").convert("RGB")
w, h = img.size; s = min(w, h)
img = img.crop(((w - s) // 2, (h - s) // 2, (w - s) // 2 + s, (h - s) // 2 + s)).resize((160, 160))
interp.set_tensor(inp["index"], np.asarray(img, dtype=np.uint8)[None])
interp.invoke()
probs = interp.get_tensor(out["index"])[0] / 256.0
for i in np.argsort(-probs)[:3]:
    print(f"{probs[i]:.2f}  {labels[i]}")

How it was trained

MobileNetV2 1.0 at 160 px initialized from timm's mobilenetv2_100.ra_in1k ImageNet weights, hard labels, 12 epochs over the full iNat2021 training split (90,048 fungus images), random resized crops, flips and color jitter, AdamW with cosine decay. About four hours in PyTorch on a laptop GPU through MPS, transplanted into Keras with a positional weight copy that verifies to a millionth, then exported with TensorFlow's full-integer converter calibrated on 300 training images. Every script is in the GitHub repository; the README's "The students" section lists what was tried and measured not to help.

Provenance and license

Weights Apache-2.0, trained in the species-classifiers repository. Initialized from timm's ImageNet weights (Apache-2.0). Training images from the iNaturalist 2021 competition dataset; species names and taxonomy in labels.txt and classes.json come from it. The same files, with checksums, are in GitHub release v0.1.0.

Also a public Edge Impulse project that deploys straight to supported boards: https://studio.edgeimpulse.com/public/1133231/latest. And on Kaggle Models beside Google's originals: https://www.kaggle.com/models/mgraham0/species-classifiers

Not affiliated with iNaturalist or Google. Not a substitute for an expert when a mushroom is going anywhere near a plate.