efficientnet-lite4-11-int8

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EfficientNet-Lite4

Use Cases

EfficientNet-Lite4 is an image classification model that achieves state-of-the-art accuracy. It is designed to run on mobile CPU, GPU, and EdgeTPU devices, allowing for applications on mobile and loT, where computational resources are limited.

Description

EfficientNet-Lite 4 is the largest variant and most accurate of the set of EfficientNet-Lite model. It is an integer-only quantized model that produces the highest accuracy of all of the EfficientNet models. It achieves 80.4% ImageNet top-1 accuracy, while still running in real-time (e.g. 30ms/image) on a Pixel 4 CPU.

Model

The fp32 Top-1 accuracy got by Intel® Neural Compressor is 77.70%, and compared with this value, int8 EfficientNet-Lite4's Top-1 accuracy drop ratio is 0.18% and performance improvement is 1.12x.

Note

The performance depends on the test hardware. Performance data here is collected with Intel® Xeon® Platinum 8280 Processor, 1s 4c per instance, CentOS Linux 8.3, data batch size is 1.

Source

Tensorflow EfficientNet-Lite4 => ONNX EfficientNet-Lite4 ONNX EfficientNet-Lite4 => Quantized ONNX EfficientNet-Lite4

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Inference

Running Inference

The following steps show how to run the inference using onnxruntime.

import onnxruntime as rt

load model

Start from ORT 1.10, ORT requires explicitly setting the providers parameter if you want to use execution providers

other than the default CPU provider (as opposed to the previous behavior of providers getting set/registered by default

based on the build flags) when instantiating InferenceSession.

For example, if NVIDIA GPU is available and ORT Python package is built with CUDA, then call API as following:

rt.InferenceSession(path/to/model, providers=['CUDAExecutionProvider'])

sess = rt.InferenceSession(MODEL + ".onnx")

run inference

results = sess.run(["Softmax:0"], {"images:0": img_batch})[0]

Input to model

Input image to model is resized to shape float32[1,224,224,3]. The batch size is 1, with 224 x 224 height and width dimensions. The input is an RBG image that has 3 channels: red, green, and blue. Inference was done using a jpg image.

Preprocessing steps

The following steps show how to preprocess the input image. For more details visit this conversion notebook.

import numpy as np import math import matplotlib.pyplot as plt import onnxruntime as rt import cv2 import json

load the labels text file

labels = json.load(open("labels_map.txt", "r"))

set image file dimensions to 224x224 by resizing and cropping image from center

def pre_process_edgetpu(img, dims): output_height, output_width, _ = dims img = resize_with_aspectratio(img, output_height, output_width, inter_pol=cv2.INTER_LINEAR) img = center_crop(img, output_height, output_width) img = np.asarray(img, dtype='float32')

converts jpg pixel value from [0 - 255] to float array [-1.0 - 1.0]

img -= [127.0, 127.0, 127.0] img /= [128.0, 128.0, 128.0] return img

resize the image with a proportional scale

def resize_with_aspectratio(img, out_height, out_width, scale=87.5, inter_pol=cv2.INTER_LINEAR): height, width, _ = img.shape new_height = int(100. * out_height / scale) new_width = int(100. * out_width / scale) if height > width: w = new_width h = int(new_height * height / width) else: h = new_height w = int(new_width * width / height) img = cv2.resize(img, (w, h), interpolation=inter_pol) return img

crop the image around the center based on given height and width

def center_crop(img, out_height, out_width): height, width, _ = img.shape left = int((width - out_width) / 2) right = int((width + out_width) / 2) top = int((height - out_height) / 2) bottom = int((height + out_height) / 2) img = img[top:bottom, left:right] return img

read the image

fname = "image_file" img = cv2.imread(fname) img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)

pre-process the image like mobilenet and resize it to 224x224

img = pre_process_edgetpu(img, (224, 224, 3)) plt.axis('off') plt.imshow(img) plt.show()

create a batch of 1 (that batch size is buned into the saved_model)

img_batch = np.expand_dims(img, axis=0)

Output of model

Output of model is an inference score with array shape float32[1,1000]. The output references the labels_map.txt file which maps an index to a label to classify the type of image.

Postprocessing steps

The following steps detail how to print the output results of the model.

load the model

Start from ORT 1.10, ORT requires explicitly setting the providers parameter if you want to use execution providers

other than the default CPU provider (as opposed to the previous behavior of providers getting set/registered by default

based on the build flags) when instantiating InferenceSession.

For example, if NVIDIA GPU is available and ORT Python package is built with CUDA, then call API as following:

rt.InferenceSession(path/to/model, providers=['CUDAExecutionProvider'])

sess = rt.InferenceSession(MODEL + ".onnx")

run inference and print results

results = sess.run(["Softmax:0"], {"images:0": img_batch})[0] result = reversed(results[0].argsort()[-5:]) for r in result: print(r, labels[str(r)], results[0][r])

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Dataset (Train and validation)

The model was trained using COCO 2017 Train Images, Val Images, and Train/Val annotations.

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Validation

Refer to efficientnet-lite4 conversion notebook for details of how to use it and reproduce accuracy.

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Quantization

EfficientNet-Lite4-int8 and EfficientNet-Lite4-qdq are obtained by quantizing fp32 CaffeNet model. We use Intel® Neural Compressor with onnxruntime backend to perform quantization. View the instructions to understand how to use Intel® Neural Compressor for quantization.

Environment

onnx: 1.9.0 onnxruntime: 1.8.0

Prepare model

wget https://github.com/onnx/models/raw/main/vision/classification/efficientnet-lite4/model/efficientnet-lite4-11.onnx

Model quantize

Make sure to specify the appropriate dataset path in the configuration file.

bash run_tuning.sh --input_model=path/to/model \  # model path as *.onnx
--config=efficientnet.yaml \
--output_model=path/to/save

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References

• Tensorflow to Onnx conversion tutorial. The Juypter Notebook references how to run an evaluation on the efficientnet-lite4 model and export it as a saved model. It also details how to convert the tensorflow model into onnx, and how to run its preprocessing and postprocessing code for the inputs and outputs.

• Refer to this paper for more details on the model.

• Intel® Neural Compressor

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Contributors

• Shirley Su
• mengniwang95 (Intel)
• airMeng (Intel)
• ftian1 (Intel)
• hshen14 (Intel)

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License

MIT License

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