captcha/predict.py

import torch
from torchvision import transforms
from PIL import Image
import matplotlib.pyplot as plt
from cnn_net import ConvNet
import os
import random
import captcha_settings
import one_hot_encoding

device = "cuda" if torch.cuda.is_available() else "mps" if torch.backends.mps.is_available() else "cpu"
print(f"Using {device} device")

def predict(model, file_path):
    trans = transforms.Compose([
        transforms.ToTensor(),
        transforms.Grayscale()
    ])
    with torch.no_grad():
        X = trans(Image.open(file_path)).reshape(1, 1, 60, 160)
        X = X.to(device)
        pred = model(X)
        text = one_hot_encoding.decode(pred)
        return text

def main():
    model = ConvNet().to(device)
    model.load_state_dict(torch.load(f"./model.pth", weights_only=True))
    model.eval()

    # random pickup some test images
    pickup_count = int(input("输入验证集的图片长度（默认30）：") or 30)
    input_rect = input("输入图片的行数和列数（默认5x6）：")
    pickup_rect = [int(i) for i in input_rect.split("x")] if input_rect else [5, 6]
    files = os.listdir(captcha_settings.PREDICT_DATASET_PATH)
    images_picked = random.sample(files, pickup_count)
    
    # show as a grid, with predicted text, correct or not
    fig, axes = plt.subplots(nrows=pickup_rect[0], ncols=pickup_rect[1], figsize=(10, 8))
    for i, image_name in enumerate(images_picked):
        real_text = image_name.split(".")[0].split("_")[-1]
        file_path = os.path.join(captcha_settings.PREDICT_DATASET_PATH, image_name)
        pred_text = predict(model, file_path)
        correct = real_text == pred_text
        axes[i//pickup_rect[1], i%pickup_rect[1]].imshow(plt.imread(file_path))
        axes[i//pickup_rect[1], i%pickup_rect[1]].set_title(f"{pred_text}, {'yes' if correct else 'no'}")
        axes[i//pickup_rect[1], i%pickup_rect[1]].axis('off')
    plt.show()

if __name__ == "__main__":
    main()