Hi @kzezel,
You can consider taking one of the examples in open-source Standard SDK as a reference (https://github.com/ambiot/ambpro2_sdk/blob/main/project/realtek_amebapro2_v0_example/src/mmfv2_video_example/mmf2_video_example_vipnn_rtsp_init.c), this is an object detection demo, but this method should work for face detection also.
There’s an example on how to do cropping and resizing of your original video.
You can set use_roi parameter to 1 and your video will be cropped according to your ROI parameter settings. If use_roi parameter is set to 1, original video will be crop/resize using the area defined by four parameters (xmin, ymin, xmax, ymax). But based on current Arduino SDK API, the image that you cropped will be scaled according to the resolution of the video.
If you would like cropping function based on face coordinates to be added into the Arduino SDK, you may submit a feature request on GitHub (GitHub - ambiot/ambpro2_arduino) and we will discuss internally to see if it is feasible to add it into the Arduino SDK. However, it will take some time for us to add it in.
Thank you, hope it helps!