Make a layer over an image and adjust its co-ordinates by touch

Question

I need to make a layer over an image and adjust the layer to fit to image and get its co-ordinates of the layer.

I need to adjust the layer by touch and pinch.

The sample image is as below. I need to do this in ios, and can I get any ideas to do this?

Answer 1

Use coreImage's Face detection API to detect Bound of Face, and CGPoint of Left eye, Right eye and mouth. Use Bezier path to draw a purple line path against each face feature as you have shown in picture.

If you want to be more precise better use openCV to detect edges against each face feature.