如何在tensorflow/keras中使用常量滤波器进行卷积

import tensorflow as tf
from tensorflow.keras.layers import Conv2D

filter = tf.constant([[1, 1, 1], [1, 1, 1], [1, 1, 1]], dtype=tf.float32)

conv_layer = Conv2D(filters=1, kernel_size=3, strides=1, padding='same', use_bias=False)
output = conv_layer(filter)

print(output)