改进代码，测试集：用于最终的模型性能评估，路径为 "C:\Users\24067\Desktop\peach_split\test"。没有标签集

为了改进代码以适应没有标签的测试集，并进行最终的模型性能评估，可以按照以下步骤进行修改：

1. **移除测试集的标签加载部分**：因为测试集没有标签，所以不需要加载标签。
2. **直接对测试集进行预测**：将预测结果保存到指定的输出路径。
3. **调整评估函数**：如果需要在验证集上进行评估，可以在训练后调用评估函数。

以下是改进后的代码：

import os
import json
import numpy as np
import pandas as pd
from PIL import Image
import tensorflow as tf
from sklearn.model_selection import train_test_split
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Conv2D, MaxPooling2D, Flatten, Dense, Dropout
from tensorflow.keras.preprocessing.image import ImageDataGenerator
from tensorflow.keras.optimizers import Adam
from sklearn.metrics import f1_score, accuracy_score

# 定义数据路径
TRAIN_DATA_DIR = "C:\\Users\\24067\\Desktop\\peach_split\\train"
VAL_DATA_DIR = "C:\\Users\\24067\\Desktop\\peach_split\\val"
TEST_DATA_DIR = "C:\\Users\\24067\\Desktop\\peach_split\\test"
TRAIN_LABEL_PATH = "C:\\Users\\24067\\Desktop\\train_label.json"
VAL_LABEL_PATH = "C:\\Users\\24067\\Desktop\\val_label.json"
OUTPUT_PATH = "C:\\Users\\24067\\Desktop\\data\\submission.csv"

# 加载数据集
def load_data(data_dir, label_path):
    with open(label_path, 'r') as f:
        labels_list = json.load(f)
    labels = {item['文件名']: item['标签'] for item in labels_list if '文件名' in item and '标签' in item}
    
    images = []
    targets = []
    for file_name, label in labels.items():
        img_path = os.path.join(data_dir, file_name)
        if not os.path.exists(img_path):
            continue
        img = Image.open(img_path).resize((128, 128))
        img_array = np.array(img) / 255.0
        images.append(img_array)
        targets.append(label)
    
    if len(images) == 0:
        raise ValueError("No valid images found.")
    
    return np.array(images), np.array(targets)

# 加载训练数据
train_images, train_labels = load_data(TRAIN_DATA_DIR, TRAIN_LABEL_PATH)

# 加载验证数据
val_images, val_labels = load_data(VAL_DATA_DIR, VAL_LABEL_PATH)

# 标签映射
label_map = {'特级': 3, '一级': 2, '二级': 1, '三级': 0}
train_labels = np.array([label_map[label] for label in train_labels])
val_labels = np.array([label_map[label] for label in val_labels])

# 创建模型
def create_model(input_shape=(128, 128, 3)):
    model = Sequential([
        Conv2D(32, (3, 3), activation='relu', input_shape=input_shape),
        MaxPooling2D((2, 2)),
        Conv2D(64, (3, 3), activation='relu'),
        MaxPooling2D((2, 2)),
        Conv2D(128, (3, 3), activation='relu'),
        MaxPooling2D((2, 2)),
        Flatten(),
        Dense(128, activation='relu'),
        Dropout(0.5),
        Dense(4, activation='softmax')
    ])
    return model

# 实例化模型
model = create_model()

# 编译模型
model.compile(optimizer=Adam(learning_rate=0.001), loss='sparse_categorical_crossentropy', metrics=['accuracy'])

# 图像增强
datagen = ImageDataGenerator(
    rotation_range=20,
    width_shift_range=0.2,
    height_shift_range=0.2,
    horizontal_flip=True,
    vertical_flip=True
)

# 训练模型
history = model.fit(datagen.flow(train_images, train_labels, batch_size=32), epochs=1, validation_data=(val_images, val_labels))

# 评估模型
def evaluate_model(model, X, y):
    predictions = model.predict(X)
    predicted_labels = np.argmax(predictions, axis=1)
    accuracy = accuracy_score(y, predicted_labels)
    f1 = f1_score(y, predicted_labels, average='weighted')
    print(f'Accuracy: {accuracy:.4f}')
    print(f'F1 Score: {f1:.4f}')
    return accuracy, f1

evaluate_model(model, val_images, val_labels)

# 预测测试集并保存结果
def predict_and_save(test_data_dir, output_path):
    test_images = []
    test_file_names = []
    
    for file_name in os.listdir(test_data_dir):
        img_path = os.path.join(test_data_dir, file_name)
        if not os.path.exists(img_path):
            continue
        img = Image.open(img_path).resize((128, 128))
        img_array = np.array(img) / 255.0
        test_images.append(img_array)
        test_file_names.append(file_name)
    
    test_images = np.array(test_images)
    predictions = model.predict(test_images)
    predicted_labels = np.argmax(predictions, axis=1)
    label_map_inv = {v: k for k, v in label_map.items()}
    predicted_labels = [label_map_inv[label] for label in predicted_labels]
    
    submission_df = pd.DataFrame({'文件名': test_file_names, '标签': predicted_labels})
    submission_df.to_csv(output_path, index=False)

# 进行预测并保存结果
predict_and_save(TEST_DATA_DIR, OUTPUT_PATH)

### 主要改动点：
1. **移除了测试集标签加载的部分**：不再需要 `TEST_LABEL_PATH` 和相关加载逻辑。
2. **直接对测试集进行预测**：在 `predict_and_save` 函数中，遍历测试目录中的所有图像文件，进行预处理和预测，然后将结果保存到 CSV 文件中。
3. **保留了验证集的评估**：在训练完成后，仍然使用验证集进行模型性能评估。