# Mobile and Embedded Vision Applications Network series

## Overview

MobileNetV1 is a network launched by Google in 2017 for use on mobile devices or embedded devices. The network replaces the depthwise separable convolution with the traditional convolution operation, that is, the combination of depthwise convolution and pointwise convolution. Compared with the traditional convolution operation, this combination can greatly save the number of parameters and computation. At the same time, MobileNetV1 can also be used for object detection, image segmentation and other visual tasks.

MobileNetV2 is a lightweight network proposed by Google following MobileNetV1. Compared with MobileNetV1, MobileNetV2 proposed Linear bottlenecks and Inverted residual block as a basic network structures, to constitute MobileNetV2 network architecture through stacking these basic module a lot. In the end, higher classification accuracy was achieved when FLOPS was only half of MobileNetV1.

The ShuffleNet series network is the lightweight network structure proposed by MEGVII. So far, there are two typical structures in this series network, namely, ShuffleNetV1 and ShuffleNetV2. A Channel Shuffle operation in ShuffleNet can exchange information between groups and perform end-to-end training. In the paper of ShuffleNetV2, the author proposes four criteria for designing lightweight networks, and designs the ShuffleNetV2 network according to the four criteria and the shortcomings of ShuffleNetV1.

MobileNetV3 is a new and lightweight network based on NAS proposed by Google in 2019. In order to further improve the effect, the activation functions of relu and sigmoid were replaced with hard_swish and hard_sigmoid activation functions, and some improved strategies were introduced to reduce the amount of network computing.

GhosttNet is a brand-new lightweight network structure proposed by Huawei in 2020. By introducing the ghost module, the problem of redundant calculation of features in traditional deep networks is greatly alleviated, which greatly reduces the amount of network parameters and calculations.

![](../../images/models/mobile_arm_top1.png)

![](../../images/models/mobile_arm_storage.png)

![](../../images/models/T4_benchmark/t4.fp32.bs4.mobile_trt.flops.png)

![](../../images/models/T4_benchmark/t4.fp32.bs4.mobile_trt.params.png)

Currently there are 32 pretrained models of the mobile series open source by PaddleClas, and their indicators are shown in the figure below. As you can see from the picture, newer lightweight models tend to perform better, and MobileNetV3 represents the latest lightweight neural network architecture. In MobileNetV3, the author used 1x1 convolution after global-avg-pooling in order to obtain higher accuracy,this operation significantly increases the number of parameters but has little impact on the amount of computation, so if the model is evaluated from a storage perspective of excellence, MobileNetV3 does not have much advantage, but because of its smaller computation, it has a faster inference speed. In addition, the SSLD distillation model in our model library performs excellently, refreshing the accuracy of the current lightweight model from various perspectives. Due to the complex structure and many branches of the MobileNetV3 model, which is not GPU friendly, the GPU inference speed is not as good as that of MobileNetV1.

## Accuracy, FLOPS and Parameters

| Models                               | Top1    | Top5    | Reference<br>top1 | Reference<br>top5 | FLOPS<br>(G) | Parameters<br>(M) |
|:--:|:--:|:--:|:--:|:--:|:--:|:--:|
| MobileNetV1_x0_25                    | 0.514   | 0.755   | 0.506             |                   | 0.070        | 0.460             |
| MobileNetV1_x0_5                     | 0.635   | 0.847   | 0.637             |                   | 0.280        | 1.310             |
| MobileNetV1_x0_75                    | 0.688   | 0.882   | 0.684             |                   | 0.630        | 2.550             |
| MobileNetV1                          | 0.710   | 0.897   | 0.706             |                   | 1.110        | 4.190             |
| MobileNetV1_ssld                     | 0.779   | 0.939   |                   |                   | 1.110        | 4.190             |
| MobileNetV2_x0_25                    | 0.532   | 0.765   |                   |                   | 0.050        | 1.500             |
| MobileNetV2_x0_5                     | 0.650   | 0.857   | 0.654             | 0.864             | 0.170        | 1.930             |
| MobileNetV2_x0_75                    | 0.698   | 0.890   | 0.698             | 0.896             | 0.350        | 2.580             |
| MobileNetV2                          | 0.722   | 0.907   | 0.718             | 0.910             | 0.600        | 3.440             |
| MobileNetV2_x1_5                     | 0.741   | 0.917   |                   |                   | 1.320        | 6.760             |
| MobileNetV2_x2_0                     | 0.752   | 0.926   |                   |                   | 2.320        | 11.130            |
| MobileNetV2_ssld                     | 0.7674  | 0.9339  |                   |                   | 0.600        | 3.440             |
| MobileNetV3_large_<br>x1_25          | 0.764   | 0.930   | 0.766             |                   | 0.714        | 7.440             |
| MobileNetV3_large_<br>x1_0           | 0.753   | 0.923   | 0.752             |                   | 0.450        | 5.470             |
| MobileNetV3_large_<br>x0_75          | 0.731   | 0.911   | 0.733             |                   | 0.296        | 3.910             |
| MobileNetV3_large_<br>x0_5           | 0.692   | 0.885   | 0.688             |                   | 0.138        | 2.670             |
| MobileNetV3_large_<br>x0_35          | 0.643   | 0.855   | 0.642             |                   | 0.077        | 2.100             |
| MobileNetV3_small_<br>x1_25          | 0.707   | 0.895   | 0.704             |                   | 0.195        | 3.620             |
| MobileNetV3_small_<br>x1_0           | 0.682   | 0.881   | 0.675             |                   | 0.123        | 2.940             |
| MobileNetV3_small_<br>x0_75          | 0.660   | 0.863   | 0.654             |                   | 0.088        | 2.370             |
| MobileNetV3_small_<br>x0_5           | 0.592   | 0.815   | 0.580             |                   | 0.043        | 1.900             |
| MobileNetV3_small_<br>x0_35          | 0.530   | 0.764   | 0.498             |                   | 0.026        | 1.660             |
| MobileNetV3_small_<br>x0_35_ssld          | 0.556   | 0.777   | 0.498             |                   | 0.026        | 1.660             |
| MobileNetV3_large_<br>x1_0_ssld      | 0.790   | 0.945   |                   |                   | 0.450        | 5.470             |
| MobileNetV3_large_<br>x1_0_ssld_int8 | 0.761   |         |                   |                   |              |                   |
| MobileNetV3_small_<br>x1_0_ssld      | 0.713   | 0.901   |                   |                   | 0.123        | 2.940             |
| ShuffleNetV2                         | 0.688   | 0.885   | 0.694             |                   | 0.280        | 2.260             |
| ShuffleNetV2_x0_25                   | 0.499   | 0.738   |                   |                   | 0.030        | 0.600             |
| ShuffleNetV2_x0_33                   | 0.537   | 0.771   |                   |                   | 0.040        | 0.640             |
| ShuffleNetV2_x0_5                    | 0.603   | 0.823   | 0.603             |                   | 0.080        | 1.360             |
| ShuffleNetV2_x1_5                    | 0.716   | 0.902   | 0.726             |                   | 0.580        | 3.470             |
| ShuffleNetV2_x2_0                    | 0.732   | 0.912   | 0.749             |                   | 1.120        | 7.320             |
| ShuffleNetV2_swish                   | 0.700   | 0.892   |                   |                   | 0.290        | 2.260             |
| GhostNet_x0_5                        | 0.668   | 0.869   | 0.662             | 0.866             | 0.082        | 2.600             |
| GhostNet_x1_0                        | 0.740   | 0.916   | 0.739             | 0.914             | 0.294        | 5.200             |
| GhostNet_x1_3                        | 0.757   | 0.925   | 0.757             | 0.927             | 0.440        | 7.300             |


## Inference speed and storage size based on SD855

| Models                               | Batch Size=1(ms) | Storage Size(M) |
|:--:|:--:|:--:|
| MobileNetV1_x0_25                    | 3.220            | 1.900           |
| MobileNetV1_x0_5                     | 9.580            | 5.200           |
| MobileNetV1_x0_75                    | 19.436           | 10.000          |
| MobileNetV1                          | 32.523           | 16.000          |
| MobileNetV1_ssld                     | 32.523           | 16.000          |
| MobileNetV2_x0_25                    | 3.799            | 6.100           |
| MobileNetV2_x0_5                     | 8.702            | 7.800           |
| MobileNetV2_x0_75                    | 15.531           | 10.000          |
| MobileNetV2                          | 23.318           | 14.000          |
| MobileNetV2_x1_5                     | 45.624           | 26.000          |
| MobileNetV2_x2_0                     | 74.292           | 43.000          |
| MobileNetV2_ssld                     | 23.318           | 14.000          |
| MobileNetV3_large_x1_25          | 28.218           | 29.000          |
| MobileNetV3_large_x1_0           | 19.308           | 21.000          |
| MobileNetV3_large_x0_75          | 13.565           | 16.000          |
| MobileNetV3_large_x0_5           | 7.493            | 11.000          |
| MobileNetV3_large_x0_35          | 5.137            | 8.600           |
| MobileNetV3_small_x1_25          | 9.275            | 14.000          |
| MobileNetV3_small_x1_0           | 6.546            | 12.000          |
| MobileNetV3_small_x0_75          | 5.284            | 9.600           |
| MobileNetV3_small_x0_5           | 3.352            | 7.800           |
| MobileNetV3_small_x0_35          | 2.635            | 6.900           |
| MobileNetV3_small_x0_35_ssld          | 2.635            | 6.900           |
| MobileNetV3_large_x1_0_ssld      | 19.308           | 21.000          |
| MobileNetV3_large_x1_0_ssld_int8 | 14.395           | 10.000          |
| MobileNetV3_small_x1_0_ssld      | 6.546            | 12.000          |
| ShuffleNetV2                         | 10.941           | 9.000           |
| ShuffleNetV2_x0_25                   | 2.329            | 2.700           |
| ShuffleNetV2_x0_33                   | 2.643            | 2.800           |
| ShuffleNetV2_x0_5                    | 4.261            | 5.600           |
| ShuffleNetV2_x1_5                    | 19.352           | 14.000          |
| ShuffleNetV2_x2_0                    | 34.770           | 28.000          |
| ShuffleNetV2_swish                   | 16.023           | 9.100           |
| GhostNet_x0_5                   | 5.714           | 10.000           |
| GhostNet_x1_0                   | 13.558           | 20.000           |
| GhostNet_x1_3                   | 19.982           | 29.000           |


## Inference speed based on T4 GPU

| Models            | FP16<br>Batch Size=1<br>(ms) | FP16<br>Batch Size=4<br>(ms) | FP16<br>Batch Size=8<br>(ms) | FP32<br>Batch Size=1<br>(ms) | FP32<br>Batch Size=4<br>(ms) | FP32<br>Batch Size=8<br>(ms) |
|-----------------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|-----------------------|
| MobileNetV1_x0_25           | 0.68422               | 1.13021               | 1.72095               | 0.67274               | 1.226                 | 1.84096               |
| MobileNetV1_x0_5            | 0.69326               | 1.09027               | 1.84746               | 0.69947               | 1.43045               | 2.39353               |
| MobileNetV1_x0_75           | 0.6793                | 1.29524               | 2.15495               | 0.79844               | 1.86205               | 3.064                 |
| MobileNetV1                 | 0.71942               | 1.45018               | 2.47953               | 0.91164               | 2.26871               | 3.90797               |
| MobileNetV1_ssld            | 0.71942               | 1.45018               | 2.47953               | 0.91164               | 2.26871               | 3.90797               |
| MobileNetV2_x0_25           | 2.85399               | 3.62405               | 4.29952               | 2.81989               | 3.52695               | 4.2432                |
| MobileNetV2_x0_5            | 2.84258               | 3.1511                | 4.10267               | 2.80264               | 3.65284               | 4.31737               |
| MobileNetV2_x0_75           | 2.82183               | 3.27622               | 4.98161               | 2.86538               | 3.55198               | 5.10678               |
| MobileNetV2                 | 2.78603               | 3.71982               | 6.27879               | 2.62398               | 3.54429               | 6.41178               |
| MobileNetV2_x1_5            | 2.81852               | 4.87434               | 8.97934               | 2.79398               | 5.30149               | 9.30899               |
| MobileNetV2_x2_0            | 3.65197               | 6.32329               | 11.644                | 3.29788               | 7.08644               | 12.45375              |
| MobileNetV2_ssld            | 2.78603               | 3.71982               | 6.27879               | 2.62398               | 3.54429               | 6.41178               |
| MobileNetV3_large_x1_25     | 2.34387               | 3.16103               | 4.79742               | 2.35117               | 3.44903               | 5.45658               |
| MobileNetV3_large_x1_0      | 2.20149               | 3.08423               | 4.07779               | 2.04296               | 2.9322                | 4.53184               |
| MobileNetV3_large_x0_75     | 2.1058                | 2.61426               | 3.61021               | 2.0006                | 2.56987               | 3.78005               |
| MobileNetV3_large_x0_5      | 2.06934               | 2.77341               | 3.35313               | 2.11199               | 2.88172               | 3.19029               |
| MobileNetV3_large_x0_35     | 2.14965               | 2.7868                | 3.36145               | 1.9041                | 2.62951               | 3.26036               |
| MobileNetV3_small_x1_25     | 2.06817               | 2.90193               | 3.5245                | 2.02916               | 2.91866               | 3.34528               |
| MobileNetV3_small_x1_0      | 1.73933               | 2.59478               | 3.40276               | 1.74527               | 2.63565               | 3.28124               |
| MobileNetV3_small_x0_75     | 1.80617               | 2.64646               | 3.24513               | 1.93697               | 2.64285               | 3.32797               |
| MobileNetV3_small_x0_5      | 1.95001               | 2.74014               | 3.39485               | 1.88406               | 2.99601               | 3.3908                |
| MobileNetV3_small_x0_35     | 2.10683               | 2.94267               | 3.44254               | 1.94427               | 2.94116               | 3.41082               |
| MobileNetV3_small_x0_35_ssld     | 2.10683               | 2.94267               | 3.44254               | 1.94427               | 2.94116               | 3.41082               |
| MobileNetV3_large_x1_0_ssld | 2.20149               | 3.08423               | 4.07779               | 2.04296               | 2.9322                | 4.53184               |
| MobileNetV3_small_x1_0_ssld | 1.73933               | 2.59478               | 3.40276               | 1.74527               | 2.63565               | 3.28124               |
| ShuffleNetV2                | 1.95064               | 2.15928               | 2.97169               | 1.89436               | 2.26339               | 3.17615               |
| ShuffleNetV2_x0_25          | 1.43242               | 2.38172               | 2.96768               | 1.48698               | 2.29085               | 2.90284               |
| ShuffleNetV2_x0_33          | 1.69008               | 2.65706               | 2.97373               | 1.75526               | 2.85557               | 3.09688               |
| ShuffleNetV2_x0_5           | 1.48073               | 2.28174               | 2.85436               | 1.59055               | 2.18708               | 3.09141               |
| ShuffleNetV2_x1_5           | 1.51054               | 2.4565                | 3.41738               | 1.45389               | 2.5203                | 3.99872               |
| ShuffleNetV2_x2_0           | 1.95616               | 2.44751               | 4.19173               | 2.15654               | 3.18247               | 5.46893               |
| ShuffleNetV2_swish          | 2.50213               | 2.92881               | 3.474                 | 2.5129                | 2.97422               | 3.69357               |