arcface demo

[heabeounMKTO]

• added arcface embedding extraction demo using yolov8-face to extract face keypoints and extract embedding from detected face
• added calib3d to cmake for cv::estimateAffinePartial2D
• added optional comparison function for comparing embeddings

[tencent-adm]

All committers have signed the CLA.

[github-actions]

The binary size change of libncnn.so (bytes)

architecture	base size	pr size	difference
x86_64	15307488	15208240	-99248 😘
armhf	6225824	6210540	-15284 😘
aarch64	9527072	9523592	-3480 😘

[nihui]

There is ncnn::get_affine_transform for this purpose.
so we can remove opencv_calib3d dependency.

[nihui]

port to std::vector for c++03 compatibility

[nihui]

use printf/fprintf for logging and file io
drop the iostream header

[nihui]

declare mean_vals and norm_vals as local variable

I see that only the first row is used

[nihui]

ask the user to provide two images and output the similarity

./arcface a.jpg b.jpg
a.jpg face = x y w h
b.jpg face = x y w h
similarity = 0.9555

[heabeounMKTO]

@nihui ive made changes according to your request that includes:

• replace cv::calib3d fucntion with an ncnn one
• replace std::array with std::vector
• use printf and fprintf
• local variables for mean , norm and arcface_dst
• command line args for inputting two images
  please tell me if there is anything you want to change , thanks

[nihui]

hello, please enable github action in YOUR FORKED REPO to make code-format workflow work

[heabeounMKTO]

hello, please enable github action in YOUR FORKED REPO to make code-format workflow work

I already enabled it in my forked repo in
Settings > Actions > General > Actions permissions > Allow all actions and reusable workflows

[nihui]

hello, please enable github action in YOUR FORKED REPO to make code-format workflow work

I already enabled it in my forked repo in Settings > Actions > General > Actions permissions > Allow all actions and reusable workflows

Then you need to commit and push a dummy change (eg. adding an empty line) to trigger your code-format workflow.

[nihui]

goto https://github.com/heabeounMKTO/ncnn/settings/actions

check Allow all actions and reusable workflows in Actions permissions
check Read and write permissions in Workflow permissions

push a dummy commit

[heabeounMKTO]

goto https://github.com/heabeounMKTO/ncnn/settings/actions

check Allow all actions and reusable workflows in Actions permissions check Read and write permissions in Workflow permissions

push a dummy commit

this is my permissions in the earlier commit, still doesnt seem to work?

[nihui]

https://github.com/heabeounMKTO/ncnn/actions
The enabled workflows can be found there

[heabeounMKTO]

https://github.com/heabeounMKTO/ncnn/actions The enabled workflows can be found there

ohh thanks, i am not familiar with github actions.

[heabeounMKTO]

i got an error on code format run
The job was not started because your account is locked due to a billing issue. , do i need to setup billing?

[nihui]

i got an error on code format run The job was not started because your account is locked due to a billing issue. , do i need to setup billing?

You can refer to GitHub's official documentation on creating support tickets for assistance with account and billing issues:
https://docs.github.com/en/support/contacting-github-support/creating-a-support-ticket

Since this is an account-specific issue that's preventing the workflow from running, you'll need to resolve it with GitHub Support before the code format check can complete. The pull request cannot be merged until the code format check passes.

[heabeounMKTO]

@nihui i've resolved the code formatting issue now, thanks for bearing with me!

[Copilot]

Pull Request Overview

This PR adds a new example demonstrating face recognition using YOLOv8-face for face detection and ArcFace for embedding extraction. The example loads two face images, detects faces, extracts embeddings, and computes similarity between them.

• Implements complete face detection and recognition pipeline with YOLOv8-face and ArcFace models
• Adds utility classes for bounding box management and non-maximum suppression
• Integrates the new example into the CMake build system

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 21 comments.

File	Description
examples/arcface.cpp	New example implementing face detection with YOLOv8-face and embedding extraction with ArcFace, including utilities for bbox operations, NMS, and face alignment
examples/CMakeLists.txt	Registers the new arcface example in the build system

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[heabeounMKTO]

hello @nihui , would you like me to commit the copilot suggested changes?

[nihui]

hello @nihui , would you like me to commit the copilot suggested changes?

Hello, it depends on whether you agree with copilot's suggestions. Sometimes copilot's suggested modifications are reasonable, in which case you should accept and submit the changes. Other times, they are not, in which case you should ignore them and choose to resolve conversation.

[heabeounMKTO]

ive added some suggestions from the bot @nihui , please review and give me some feedback, thanks !

[nihui]

Please add the license header at the beginning.
The rest seems fine to me.
Thank you.

[nihui]

Thanks for your contribution !

[heabeounMKTO]

Thanks for your contribution !

thank you!

[nihui]

Thanks for your contribution !

thank you!

Well, I found a few issues while testing the ArcFace sample, which I fixed.
The parts that might be helpful with you.
fec6338

[heabeounMKTO]

Well, I found a few issues while testing the ArcFace sample, which I fixed. The parts that might be helpful with you. fec6338

thanks for catching this one i copied another model that was doing conf like so [x, y, w, h, conf, class_scores..., kp1_conf, kp1_x, kp1_y] 😅