app.py

import gradio as gr
import torch
import torch.nn as nn
from torchvision import transforms
from PIL import Image
import collections

class QuantizedPlantClassifier(nn.Module): 
    def __init__(self, num_classes=39, in_features=3, base_filters=16, # conv stride stays 1, kernel size stays 3
                 n_conv_layers=6, num_fc_units=256):
        super(QuantizedPlantClassifier, self).__init__()
        # want to modularize the conv layers
        def make_conv_block(in_channels, out_channels, layer_idx=""):
            return nn.Sequential(
                collections.OrderedDict([
                    ('conv'+layer_idx, nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=0)),
                    ('bn'+layer_idx, nn.BatchNorm2d(out_channels)),
                    ('relu'+layer_idx, nn.ReLU(inplace=True)),
                    ('pool'+layer_idx, nn.MaxPool2d(kernel_size=2, stride=2))
                ])
            )
        self.quant = torch.quantization.QuantStub()
        layers = []
        current_in_channels = in_features
        for i in range(n_conv_layers):
            layers.append(make_conv_block(current_in_channels, base_filters * (2 ** i), layer_idx=str(i)))
            current_in_channels = base_filters * (2 ** i)
        self.features = nn.Sequential(*layers)

        with torch.no_grad():
            dummy_input = torch.randn(1, in_features, 256, 256)
            dummy_output = self.features(dummy_input)
            flattened_size = dummy_output.view(1, -1).shape[1]
        self.classifier = nn.Sequential(
            nn.Flatten(),
            nn.Linear(flattened_size, num_fc_units),
            nn.ReLU(inplace=True),
            nn.Dropout(0.5),
            nn.Linear(num_fc_units, num_classes)
        )
        self.dequant = torch.quantization.DeQuantStub()
        
    def forward(self, x):
        x = self.quant(x)
        x = self.features(x)
        x = self.classifier(x)
        x = self.dequant(x)
        return x

# loading model
model = QuantizedPlantClassifier()
model.eval()
model.qconfig = torch.quantization.get_default_qconfig('fbgemm')
torch.quantization.prepare(model, inplace=True)
torch.quantization.convert(model, inplace=True)

model.load_state_dict(torch.load("model_dict.pth")) 

classes = ['Apple___Apple_scab',
 'Apple___Black_rot',
 'Apple___Cedar_apple_rust',
 'Apple___healthy',
 'Background_without_leaves',
 'Blueberry___healthy',
 'Cherry___Powdery_mildew',
 'Cherry___healthy',
 'Corn___Cercospora_leaf_spot Gray_leaf_spot',
 'Corn___Common_rust',
 'Corn___Northern_Leaf_Blight',
 'Corn___healthy',
 'Grape___Black_rot',
 'Grape___Esca_(Black_Measles)',
 'Grape___Leaf_blight_(Isariopsis_Leaf_Spot)',
 'Grape___healthy',
 'Orange___Haunglongbing_(Citrus_greening)',
 'Peach___Bacterial_spot',
 'Peach___healthy',
 'Pepper,_bell___Bacterial_spot',
 'Pepper,_bell___healthy',
 'Potato___Early_blight',
 'Potato___Late_blight',
 'Potato___healthy',
 'Raspberry___healthy',
 'Soybean___healthy',
 'Squash___Powdery_mildew',
 'Strawberry___Leaf_scorch',
 'Strawberry___healthy',
 'Tomato___Bacterial_spot',
 'Tomato___Early_blight',
 'Tomato___Late_blight',
 'Tomato___Leaf_Mold',
 'Tomato___Septoria_leaf_spot',
 'Tomato___Spider_mites Two-spotted_spider_mite',
 'Tomato___Target_Spot',
 'Tomato___Tomato_Yellow_Leaf_Curl_Virus',
 'Tomato___Tomato_mosaic_virus',
 'Tomato___healthy']

transform = transforms.Compose([
    transforms.Resize((256, 256)),
    transforms.ToTensor(),
])

def predict(img: Image.Image):
    img = transform(img).unsqueeze(0)
    with torch.no_grad():
        logits = model(img)
        probs = torch.softmax(logits, dim=1)[0]

    return {classes[i]: float(probs[i]) for i in range(len(classes))}

demo = gr.Interface(
    fn=predict,
    inputs=gr.Image(type="pil"),
    outputs=gr.Label(num_top_classes=3),
    title="Image Classifier Demo",
    description="Upload an image to get predictions with confidence scores."
)

demo.launch()