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Appendix A. Specifications#

Runtime performance#

Mobile environment#

Face detection performance depends on input image parameters such as resolution and bit depth as well as the size of the detected face. The Android platform uses mobilenet by default.

Input data characteristics:

  • Image resolution: 640x480px;
  • Image format: 24 BPP RGB;
  • Typical face size: ~260x260px.

Android#

Performance measurements are presented for ARM of Samsung SM-G930F and Samsung SM-J730FM in tables below. Measured values are averages of at least 100 experiments. Mobilenet is used by default. The number of threads auto means that will be taken the maximum number of available threads. For this mode use the -1 value for the numThreads parameter in the runtime.conf. This number of threads is equal to according number of available processor cores. We strongly recommend you to follow this recommendation; otherwise, performance can be significantly reduced. Description of accoding settings you can find in "Configuration Guide - Runtime settings".

"Performance of Samsung SM-G930F. Extractor and matcher"

Measurement Model Threads Average Units
Extractor 56 1 535.3 ms
56 auto 218.9
Matcher 56 - 60 K matches/sec

"Performance of Samsung SM-G930F. Extractor batch"

Measurement Model Threads Average (ms) Batch Size
Extractor Batch 56 auto 236.3 1
56 auto 255.7 4
56 auto 236.8 8

"Performance of Samsung SM-G930F. Detection and estimation"

Measurement Threads Average (ms) BatchSize
Detector (FaceDetV2) 1 78.9 / 70.8 / 286.0 -
(Easy/complex/6 faces) auto 80.2 / 70.8 / 149.5 -
Warper 1 8.4 -
auto 8.2 -
Head Pose by Image 1 6.5 -
auto 12.3 -
Head Pose Batch auto 12.0 1
auto 5.0 4
auto 3.7 8
Eyes 1 24.3 -
auto 26.9 -
Eyes Batch auto 26.5 1
auto 16.9 4
auto 12.9 8
AGS 1 6.4 -
auto 10.0 -
AGS Batch auto 10.1 1
auto 4.4 4
auto 3.5 8
BestShot Quality 1 12.8 -
auto 23.3 -
BestShot Quality Batch auto 21.7 1
auto 9.5 4
auto 7.3 8

"Performance of Samsung SM-J730FM. Extractor and matcher"

Measurement Model Threads Average Units
Extractor 56 1 891.9 ms
56 auto 280.2
Matcher 56 - 60 K matches/sec

"Performance of Samsung SM-J730FM. Extractor batch"

Measurement Model Threads Average (ms) Batch Size
Extractor Batch 56 auto 150.8 1
56 auto 167.3 4
56 auto 166.2 8

"Performance of Samsung SM-J730FM. Detection and estimation"

Measurement Threads Average(ms) BatchSize
Detector (FaceDetV2) 1 89.6 / 82.2 / 321.3 -
(Easy/complex/6 faces) auto 100.2 / 82.5 / 144.2 -
Warper 1 13.4 -
auto 13.4 -
Head Pose by Image 1 6.2 -
auto 9.0 -
Head Pose Batch auto 7.6 1
auto 4.4 4
auto 2.9 8
Eyes 1 32.2 -
auto 28.4 -
Eyes Batch 1 34.1 1
auto 38.7 8
AGS auto 7.4 -
auto 4.0 -
auto 2.9 -
AGS Batch 1 25.2 1
auto 17.9 8
BestShot Quality auto 14.1 1
auto 7.0 1
auto 5.8 1
BestShot Quality Batch auto 28.6 1
auto 17.3 4
auto 11.8 8

Descriptor size#

The table below shows size of serialized descriptors to estimate memory requirements.

"Descriptor size"

Descriptor version Data size (bytes) Metadata size (bytes) Total size
CNN 54 512 8 520

Metadata includes signature and version information that may be omitted during serialization if the NoSignature flag is specified.

When estimating individual descriptor size in memory or serialization storage requirements with default options, consider using values from the "Total size" column.

When estimating memory requirements for descriptor batches, use values from the "Data size" column instead, since a descriptor batch does not duplicate metadata per descriptor and thus is more memory-efficient.

These numbers are for approximate computation only, since they do not include overhead like memory alignment for accelerated SIMD processing and the like.

Feature matrix#

Mobile versions come in two editions: the frontend edition (or FE for short) and the complete edition.

The table below shows FaceEngine features supported by different editions of mobile platform.

"Feature matrix"

Facility Module Complete Frontend
Core Yes Yes
Face detection & alignment Face detector Yes Yes
Parameter estimation BestShotQuality estimation Yes Yes
Color estimation Yes Yes
Eye estimation Yes Yes
Head pose estimation Yes Yes
AGS estimation Yes Yes
Face descriptors Descriptor extraction Yes No
Descriptor matching Yes No
Descriptor batching Yes No
Descriptor search acceleration Yes No

See file "doc/FeatureMapMobile.htm" for more details.

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