记录如何在IOS上使用TensorflowLite部署自己的深度学习模型，后面考虑加入Android，参考TensorflowLite官网的实例。
环境配置
在自己的python 环境中使用pip 按照好 tensorflow:
pip3 install tensorflow
从github 下载工程文件:
git clone https://github.com/googlecodelabs/tensorflow-for-poets-2
下载数据集:
wget http://download.tensorflow.org/example_images/flower_photos.tgz
该数据集包含5种不同的花类型,我们用来训练模型判断花的种类
下载后解压到tensorflow-for-poets-2/tf_files/ 路径下:
Screen Shot 2018-12-15 at 5.04.17 PM.png
模型训练
在scripts路径下包含了几个脚本文件，其中retrain.py文件用于使用tensorflow 在 imagenet 数据集上训练好的 Inception和 mobilenet模型(运行的时候会自动下载)重新训练用于我们的花类型分类任务, 里面也包含了大量的可以设置的参数:
--architecture ARCHITECTURE
Which model architecture to use. 'inception_v3' is the
most accurate, but also the slowest. For faster or
smaller models, chose a MobileNet with the form
'mobilenet_<parameter size>_<input_size>[_quantized]'.
For example, 'mobilenet_1.0_224' will pick a model
that is 17 MB in size and takes 224 pixel input
images, while 'mobilenet_0.25_128_quantized' will
choose a much less accurate, but smaller and faster
network that's 920 KB on disk and takes 128x128
images. See
https://research.googleblog.com/2017/06/mobilenets-
open-source-models-for.html for more information on
Mobilenet.
训练脚本:
python scripts/retrain.py \
--output_graph=tf_files/retrained_graph.pb \
--output_labels=tf_files/retrained_labels.txt \
--image_dir=tf_files/flower_photos \
--architecture=mobilenet_1.0_224 \
--summaries_dir tf_files/training_summaries/mobilenet_1.0_244
Screen Shot 2018-12-15 at 5.16.05 PM.png
打开tensorboard可以查看finetune过程中的loss/accuracy的变化曲线:
tensorboard --logdir=tf_files/training_summaries/mobilenet_1.0_244
Screen Shot 2018-12-15 at 5.22.48 PM.png
模型转换
将训练好的静态图文件转换为tflite模型的时候我们使用google官方提供的转换工具toco, 关于toco的介绍可以查看我的另一篇文章Tensorflow移动端模型转换
IMAGE_SIZE=224
toco \
--graph_def_file=tf_files/retrained_graph.pb \
--output_file=tf_files/optimized_graph.lite \
--output_format=TFLITE \
--input_shape=1,${IMAGE_SIZE},${IMAGE_SIZE},3 \
--input_array=input \
--output_array=final_result \
--inference_type=FLOAT \
--inference_input_type=FLOAT
衡量tflite模型的准确度
实际上在转换模型的过程中我们的模型的精度会有一定损失，获得转换好的tflite模型之后，我们还是希望能够能够先衡量下转换好的模型精度，这需要直接在python脚本中调用tflite模型解释器，然后在测试数据集上计算tflite模型的精度:
下面给出一个调用的脚本(tensorflow接口变换很快，不保证可用):
import numpy as np
import tensorflow as tf
from skimage.transform import resize
import cv2
import os
def predict(interpreter, input_shape, input_data):
"""generate softmax predictions for input_data
interpreter: the enviroment to run model
input_shape: config information for resize input_data
input_data: user data
"""
input_data = resize(img, input_shape[1:])
input_data = input_data.reshape(input_shape)
input_data = input_data.astype("float32")
# input_data = (input_data - 127.5) / 127.5
interpreter.set_tensor(input_details[0]['index'], input_data)
interpreter.invoke()
output_data = interpreter.get_tensor(output_details[0]['index'])
index = np.argmax(output_data)
return index
if __name__ == "__main__":
# Load TFLite model and allocate tensors.
interpreter = tf.contrib.lite.Interpreter(model_path="tf_files/optimized_graph.tflite")
interpreter.allocate_tensors()
# Get input and output tensors.
input_details = interpreter.get_input_details()
output_details = interpreter.get_output_details()
# Test model on customer data
input_shape = input_details[0]['shape']
# load sub classes
data_path = "/Users/yuhua.cheng/Opt/temp/tensorflow-for-poets-2/tf_files/flower_photos"
sub_classes = [f for f in sorted(os.listdir(data_path))if os.path.isdir(os.path.join(data_path, f))]
print(sub_classes)
count = 0
total = 0
for label, sub_class in enumerate(sub_classes):
print("processing: ", sub_class)
sub_path = os.path.join(data_path, sub_class)
img_files = [f for f in os.listdir(sub_path) if not f.startswith('.')]
for img_file in img_files:
img = cv2.imread(os.path.join(sub_path, img_file), -1)
pred = predict(interpreter, input_shape, img)
if pred == label:
count += 1
total += 1
print('accuracy:', count / total)
在IOS工程调用tflite模型
先安装必要的相关文件:
xcode-select --install
sudo gem install cocoapods
pod install --project-directory=ios/tflite/
打开IOS工程:
open ios/tflite/tflite_camera_example.xcworkspace
将模型文件和label文件复制到工程对应路径:
cp tf_files/optimized_graph.lite ios/tflite/data/graph.lite
cp tf_files/retrained_labels.txt ios/tflite/data/labels.txt
连接手机直接运行:
在手机上复现的结果:
IMG_0014.PNG
---------后面会加入在官方教程的基础上转换以及调用自己训练好的模型结果-------
问题记录
- toco 将原有的simplenet.pb转换为tflite的时候报错:
原始模型结构:
_________________________________________________________________
Layer (type) Output Shape Param #
=================================================================
input_1 (InputLayer) (None, 227, 227, 3) 0
_________________________________________________________________
block1_0_conv (Conv2D) (None, 76, 76, 64) 9408
_________________________________________________________________
block1_0_bn (BatchNormalizat (None, 76, 76, 64) 192
_________________________________________________________________
block1_0_relu (Activation) (None, 76, 76, 64) 0
_________________________________________________________________
block1_0_dropout (Dropout) (None, 76, 76, 64) 0
_________________________________________________________________
block1_1_conv (Conv2D) (None, 76, 76, 32) 18432
_________________________________________________________________
block1_1_bn (BatchNormalizat (None, 76, 76, 32) 96
_________________________________________________________________
block1_1_relu (Activation) (None, 76, 76, 32) 0
_________________________________________________________________
block1_1_dropout (Dropout) (None, 76, 76, 32) 0
_________________________________________________________________
block2_0_conv (Conv2D) (None, 76, 76, 32) 9216
_________________________________________________________________
block2_0_bn (BatchNormalizat (None, 76, 76, 32) 96
_________________________________________________________________
block2_0_relu (Activation) (None, 76, 76, 32) 0
_________________________________________________________________
block2_0_dropout (Dropout) (None, 76, 76, 32) 0
_________________________________________________________________
block2_1_conv (Conv2D) (None, 76, 76, 32) 9216
_________________________________________________________________
block2_1_bn (BatchNormalizat (None, 76, 76, 32) 96
_________________________________________________________________
max_pooling2d_1 (MaxPooling2 (None, 38, 38, 32) 0
_________________________________________________________________
block2_1_relu (Activation) (None, 38, 38, 32) 0
_________________________________________________________________
block2_1_dropout (Dropout) (None, 38, 38, 32) 0
_________________________________________________________________
block2_2_conv (Conv2D) (None, 38, 38, 32) 9216
_________________________________________________________________
block2_2_bn (BatchNormalizat (None, 38, 38, 32) 96
_________________________________________________________________
block2_2_relu (Activation) (None, 38, 38, 32) 0
_________________________________________________________________
block2_2_dropout (Dropout) (None, 38, 38, 32) 0
_________________________________________________________________
block3_0_conv (Conv2D) (None, 38, 38, 32) 9216
_________________________________________________________________
block3_0_bn (BatchNormalizat (None, 38, 38, 32) 96
_________________________________________________________________
block3_0_relu (Activation) (None, 38, 38, 32) 0
_________________________________________________________________
block3_0_dropout (Dropout) (None, 38, 38, 32) 0
_________________________________________________________________
block4_0_conv (Conv2D) (None, 38, 38, 64) 18432
_________________________________________________________________
max_pooling2d_2 (MaxPooling2 (None, 19, 19, 64) 0
_________________________________________________________________
block4_0_bn (BatchNormalizat (None, 19, 19, 64) 192
_________________________________________________________________
block4_0_relu (Activation) (None, 19, 19, 64) 0
_________________________________________________________________
block4_0_dropout (Dropout) (None, 19, 19, 64) 0
_________________________________________________________________
block4_1_conv (Conv2D) (None, 19, 19, 64) 36864
_________________________________________________________________
block4_1_bn (BatchNormalizat (None, 19, 19, 64) 192
_________________________________________________________________
block4_1_relu (Activation) (None, 19, 19, 64) 0
_________________________________________________________________
block4_1_dropout (Dropout) (None, 19, 19, 64) 0
_________________________________________________________________
block4_2_conv (Conv2D) (None, 19, 19, 64) 36864
_________________________________________________________________
block4_2_bn (BatchNormalizat (None, 19, 19, 64) 192
_________________________________________________________________
max_pooling2d_3 (MaxPooling2 (None, 9, 9, 64) 0
_________________________________________________________________
block4_2_relu (Activation) (None, 9, 9, 64) 0
_________________________________________________________________
block4_2_dropout (Dropout) (None, 9, 9, 64) 0
_________________________________________________________________
cccp4 (Conv2D) (None, 9, 9, 256) 16640
_________________________________________________________________
cccp5 (Conv2D) (None, 9, 9, 64) 16448
_________________________________________________________________
poolcp5 (MaxPooling2D) (None, 4, 4, 64) 0
_________________________________________________________________
cccp6 (Conv2D) (None, 4, 4, 64) 36928
_________________________________________________________________
poolcp6 (GlobalMaxPooling2D) (None, 64) 0
_________________________________________________________________
dense_1 (Dense) (None, 10) 650
_________________________________________________________________
activation_1 (Activation) (None, 10) 0
=================================================================
Total params: 228,778
Trainable params: 227,946
Non-trainable params: 832
_________________________________________________________________
转换问题:
Some of the operators in the model are not supported by the standard TensorFlow Lite runtime. If you have a custom implementation for them you can disable this error with --allow_custom_ops, or by setting allow_custom_ops=True when calling tf.contrib.lite.toco_convert(). Here is a list of operators for which you will need custom implementations: Max.\n'
问题原因: keras里面一些层使用Tensorflow封装，在Tensorflow 转换为tflite的时候不完全支持: https://github.com/tensorflow/tensorflow/issues/20042
拟解决的方案: 在tensorflow中，使用tensorflow自己的实现重新实现一遍。
更新tensorflow 版本从1.10到1.12问题解决, 成功转换
pip install --upgrade tensorflow
- xcode 调用tflite报错:
Op builtin_code out or range: 82. Are you using old TFLite binary with newer model?
Registration failed.
打断点发现问题出在:
tflite::InterpreterBuilder(*model, resolver)(&interpreter);
最后发现将第一个卷积层stride 3 改为stride 2便可，可能是TFLite中没有相应的stride 3 实现。
Reference
- 如何在IOS上部署自己的深度学习模型(Tensorflow官方例子):
https://codelabs.developers.google.com/codelabs/tensorflow-for-poets-2-ios/#0 - https://v-play.net/cross-platform-development/machine-learning-add-image-classification-for-ios-and-android-with-qt-and-tensorflow
- https://heartbeat.fritz.ai/neural-networks-on-mobile-devices-with-tensorflow-lite-a-tutorial-85b41f53230c
- 如何进行模型量化: https://www.tensorflow.org/lite/performance/post_training_quantization
- tensorflow 模型和 tflite模型 准确度不一致: https://github.com/tensorflow/tensorflow/issues/21921
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