检查输入时出错：预期 conv2d_3_input 的形状为 (32, 32, 1) 但得到的数组的形状为 (32, 32, 3)

Question

我正在编写交通标志识别程序。 我使用图像大小为 32x32 像素的数据。 我创建了一个深度 CNN model 并调用它在另一个文件中进行分类。

def classify(file_path):
        global label_packed
        image = imread(file_path)
        image = tf.image.convert_image_dtype(image, tf.float32)
        image = tf.image.resize(image, size=[32, 32])
        image = np.expand_dims(image, axis=0)
        pred = model.predict(image)
        sign = labels[np.argmax(pred)]
        print(sign)
        label.configure(foreground='#011638', text=sign)

---

def show_classify_button(file_path):
    classify_b = Button(top, text="Classify Image",
                        command=lambda: classify(file_path),
                        padx=10, pady=5)
    classify_b.configure(background='#364156', foreground='white',
                         font=('arial', 10, 'bold'))
    classify_b.place(relx=0.79, rely=0.46)

---

def upload_image():
try:
    file_path = filedialog.askopenfilename()
    uploaded = Image.open(file_path)
    uploaded.thumbnail(((top.winfo_width()/2.25),
                        (top.winfo_height()/2.25)))
    im = ImageTk.PhotoImage(uploaded)
    sign_image.configure(image=im)
    sign_image.image = im
    label.configure(text='')
    show_classify_button(file_path)
except:
    pass

当我单击分类按钮时，我收到此错误：

错误信息：

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\Monster\Anaconda3\lib\tkinter__init.py", line 1705, in call__
    return self.func(*args)
  File "<ipython-input-113-c3d169264d01>", line 2, in <lambda>
    classify_b=Button(top,text="Classify Image",command=lambda: classify(file_path),padx=10,pady=5)
  File "<ipython-input-112-b328d3eae35f>", line 7, in classify
    pred = model.predict_classes([image])[0]
  File "C:\Users\Monster\Anaconda3\lib\site-packages\tensorflow\python\keras\engine\sequential.py", line 318, in predict_classes
    proba = self.predict(x, batch_size=batch_size, verbose=verbose)
  File "C:\Users\Monster\Anaconda3\lib\site-packages\tensorflow\python\keras\engine\training.py", line 1060, in predict
    x, check_steps=True, steps_name='steps', steps=steps)
  File "C:\Users\Monster\Anaconda3\lib\site-packages\tensorflow\python\keras\engine\training.py", line 2651, in _standardize_user_data
    exception_prefix='input')
  File "C:\Users\Monster\Anaconda3\lib\site-packages\tensorflow\python\keras\engine\training_utils.py", line 385, in standardize_input_data
    str(data_shape))
ValueError: Error when checking input: expected conv2d_3_input to have shape (32, 32, 1) but got array with shape (32, 32, 3)

Answer 1

您在 model 中加载了一个 RGB 图像，该图像需要一个灰度图像。 我建议你使用tf.image.rgb_to_grayscale来解决这个问题。

# ...

image = np.expand_dims(image, axis=0)
image = tf.image.rgb_to_grayscale(image)
pred = model.predict(image)

# ...