需要用到的類是：GPUImageStillCamera
作用是：拍攝某一個(gè)畫面，并且保存圖片

初始化GPUImageStillCamera需要用到sessionPreset參數(shù)設(shè)置：

Paste_Image.png

代碼如下：

//
//  ViewController.swift
//  美顏相機(jī)
//
//  Created by liyang on 16/12/19.
//  Copyright ? 2016年 liyang. All rights reserved.
//

import UIKit
import GPUImage

class ViewController: UIViewController {
    
    @IBOutlet weak var bjImg: UIImageView!
    
    fileprivate lazy var camera: GPUImageStillCamera = GPUImageStillCamera(sessionPreset: AVCaptureSessionPresetHigh, cameraPosition: .back)
    
    // 初始化濾鏡
    let bilateralFilter = GPUImageBilateralFilter() // 磨皮
    let exposureFilter = GPUImageExposureFilter() // 曝光
    let brightnessFilter = GPUImageBrightnessFilter() // 美白
    let satureationFilter = GPUImageSaturationFilter() // 飽和
    let fileterGroup = GPUImageFilterGroup()
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 1、創(chuàng)建GPUImageStillCamera
        camera.outputImageOrientation = .portrait
        
        // 2、添加濾鏡（美白、曝光、磨皮、曝光）
        let filerGroup = getGroupFileters()
        camera.addTarget(filerGroup)
        
        // 3、創(chuàng)建GPUImage，用于實(shí)時(shí)顯示畫面
        let showView = GPUImageView(frame: view.bounds)
        view.insertSubview(showView, at: 0)
        filerGroup.addTarget(showView)
        
        // 4、開始補(bǔ)抓
        camera.startCapture()
        
    }
    
    // MARK:- 旋轉(zhuǎn)鏡頭
    @IBAction func rotateCamera(_ sender: Any) {
        camera.rotateCamera()
    }
    
    // 拍攝照片
    @IBAction func takeCamera(_ sender: Any) {
        camera.capturePhotoAsImageProcessedUp(toFilter: fileterGroup, withCompletionHandler: { (image, error) in
            UIImageWriteToSavedPhotosAlbum(image!, nil, nil, nil)
            
            self.bjImg.image = image
            
            // 停止采集
//            self.camera.stopCapture()
        })
    }
    
    
    
    fileprivate func getGroupFileters() -> GPUImageFilterGroup {
        
        // 2、創(chuàng)建濾鏡（設(shè)置濾鏡的引用關(guān)系）
        bilateralFilter.addTarget(brightnessFilter)
        brightnessFilter.addTarget(exposureFilter)
        exposureFilter.addTarget(satureationFilter)
        
        // 3、設(shè)置濾鏡組鏈的起點(diǎn)&&終點(diǎn)
        fileterGroup.initialFilters = [bilateralFilter]
        fileterGroup.terminalFilter = satureationFilter
        
        return fileterGroup
    }
}

demo