ios 相机 自定义 相片的截取

前段时间公司需要做一个身份识别的功能，而系统相机无法满足要求，so自己自定义了。

上代码：

.h文件

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>

@interface ViewController : UIViewController

@property (nonatomic, strong) AVCaptureSession* session;
/**
 *  输入设备
 */
@property (nonatomic, strong) AVCaptureDeviceInput* videoInput;
/**
 *  照片输出流
 */
@property (nonatomic, strong) AVCaptureStillImageOutput* stillImageOutput;
/**
 *  预览图层
 */
@property (nonatomic, strong) AVCaptureVideoPreviewLayer* previewLayer;

/**
 *  最后的缩放比例
 */
@property(nonatomic,assign)CGFloat effectiveScale;
@property (nonatomic, strong) UIView *backView;

.m文件

在这个文件你需要什么样的相机都可以在这里面设置，需要放大放小，闪光各种功能都在此处可以设置。

@interface ViewController ()

@end

@implementation ViewController

- (void)viewWillAppear:(BOOL)animated{

    [super viewWillAppear:YES];

    if (self.session) {

        [self.session startRunning];
    }
}

- (void)viewDidDisappear:(BOOL)animated{

    [super viewDidDisappear:YES];

    if (self.session) {

        [self.session stopRunning];
    }
}

- (void)viewDidLoad {
    self.view.backgroundColor = [UIColor blackColor];

    self.backView = [[UIView alloc] initWithFrame:CGRectMake(, ,SelfWidth, SelfHeight - )];
    [self.view addSubview:self.backView];

    UIView *view = [[UIView alloc]initWithFrame:CGRectMake(SelfWidth/ - , SelfHeight -  + , , )];
    view.backgroundColor = [UIColor whiteColor];
    view.layer.cornerRadius = ;
    [view.layer masksToBounds];
    [self.view addSubview:view];

    //自己定义一个和原生的相机一样的按钮
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    button.frame = CGRectMake(SelfWidth/ - , SelfHeight -  + , , );
    button.backgroundColor = [UIColor whiteColor];
    button.layer.cornerRadius = ;
    button.layer.borderWidth = ;
    button.layer.borderColor = [UIColor blackColor].CGColor;
    [button.layer masksToBounds];
    [button addTarget:self action:@selector(buttondown) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];

   //在相机中加个框
    CALayer *Mylayer=[CALayer layer];
    Mylayer.bounds=CGRectMake(, (SelfHeight - (SelfWidth - )/1.6)/, SelfWidth - , (SelfWidth - )/1.6);
    Mylayer.position=CGPointMake(SelfWidth/, (SelfHeight - )/);
    Mylayer.masksToBounds=YES;
    Mylayer.borderWidth=;
    Mylayer.borderColor=[UIColor whiteColor].CGColor;
    [self.view.layer addSublayer:Mylayer];

    UIButton *Lbtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    Lbtn.frame = CGRectMake(, SelfHeight -  , , );
    [Lbtn setTitle:@"取消" forState:UIControlStateNormal];
    Lbtn.titleLabel.font = [UIFont  systemFontOfSize:];
    [Lbtn setTintColor:[UIColor whiteColor]];
    [Lbtn addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:Lbtn];

    [self initAVCaptureSession]; //设置相机属性
    self.effectiveScale = 1.0f;
}

//设置相机属性
- (void)initAVCaptureSession{

    self.session = [[AVCaptureSession alloc] init];
    [self.session setSessionPreset:AVCaptureSessionPresetHigh];

    NSError *error;

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    //更改这个设置的时候必须先锁定设备，修改完后再解锁，否则崩溃
    [device lockForConfiguration:nil];
    //设置闪光灯为自动
    [device setFlashMode:AVCaptureFlashModeAuto];
    [device unlockForConfiguration];

    self.videoInput = [[AVCaptureDeviceInput alloc] initWithDevice:device error:&error];
    AVCaptureVideoDataOutput *captureOutput = [[AVCaptureVideoDataOutput alloc] init];
    if (error) {
        NSLog(@"%@",error);
    }
    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    //输出设置。AVVideoCodecJPEG   输出jpeg格式图片
    NSDictionary * outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey, nil];
    [self.stillImageOutput setOutputSettings:outputSettings];

    if ([self.session canAddInput:self.videoInput]) {
        [self.session addInput:self.videoInput];
    }
    if ([self.session canAddOutput:captureOutput]) {
        [self.session addOutput:captureOutput];
    }
    if ([self.session canAddOutput:self.stillImageOutput]) {
        [self.session addOutput:self.stillImageOutput];
    }

    //初始化预览图层
    self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
    [self.previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    NSLog(@"%f",SelfWidth);
    self.previewLayer.frame = CGRectMake(, ,SelfWidth, SelfHeight - );
    self.backView.layer.masksToBounds = YES;
    [self.backView.layer addSublayer:self.previewLayer];
}
- (AVCaptureVideoOrientation)avOrientationForDeviceOrientation:(UIDeviceOrientation)deviceOrientation
{
    AVCaptureVideoOrientation result = (AVCaptureVideoOrientation)deviceOrientation;
    if ( deviceOrientation == UIDeviceOrientationLandscapeLeft )
        result = AVCaptureVideoOrientationLandscapeRight;
    else if ( deviceOrientation == UIDeviceOrientationLandscapeRight )
        result = AVCaptureVideoOrientationLandscapeLeft;
    return result;
}

//照相按钮点击事件
-(void)buttondown{
    NSLog(@"takephotoClick...");
    AVCaptureConnection *stillImageConnection = [self.stillImageOutput connectionWithMediaType:AVMediaTypeVideo];
    UIDeviceOrientation curDeviceOrientation = [[UIDevice currentDevice] orientation];
    AVCaptureVideoOrientation avcaptureOrientation = [self avOrientationForDeviceOrientation:curDeviceOrientation];
    [stillImageConnection setVideoOrientation:avcaptureOrientation];
    [stillImageConnection setVideoScaleAndCropFactor:self.effectiveScale];

    [self.stillImageOutput captureStillImageAsynchronouslyFromConnection:stillImageConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {

        NSData *jpegData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];

        [self makeImageView:jpegData];
        NSLog(@"jpegDatajpegData == %ld",(unsigned long)[jpegData length]/);

    }];
}

//拍照之后调到相片详情页面
-(void)makeImageView:(NSData*)data{

    imageDetailViewController*imageView = [[imageDetailViewController alloc] init];
    imageView.data = data;

    [self presentViewController:imageView animated:NO completion:nil];

}
//返回
-(void)back{

    [self dismissViewControllerAnimated:YES completion:nil];
}

再进入详情页面进行照片的裁剪并显示

#import <UIKit/UIKit.h>

@interface imageDetailViewController : UIViewController

@property(nonatomic,strong)NSData *data;
@end

#import "imageDetailViewController.h"

@interface imageDetailViewController ()
{
    UIImage *imageIm;

}
@end

@implementation imageDetailViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor blackColor];
    UIImageView *imageView =[[UIImageView alloc] initWithFrame:CGRectMake(, -, SelfWidth, SelfHeight)];
    imageView.image = [UIImage imageWithData:_data];
    [self.view addSubview:imageView];
   imageIm =[UIImage imageWithData:_data];
    CGSize originalsize = [ imageView.image size];

     NSLog(@"改变前图片的宽度为%f,图片的高度为%f",originalsize.width,originalsize.height);
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    button.frame = CGRectMake(, SelfHeight - , , );
    [button setTitle:@"重拍" forState:UIControlStateNormal];
    [button setTintColor:[UIColor whiteColor]];
    [button addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];

    CALayer *Mylayer=[CALayer layer];
    Mylayer.bounds=CGRectMake(, (SelfHeight - (SelfWidth - )/1.6)/, SelfWidth - , (SelfWidth - )/1.6);
    Mylayer.position=CGPointMake(SelfWidth/, (SelfHeight - )/);
    Mylayer.masksToBounds=YES;
    Mylayer.borderWidth=;
    Mylayer.borderColor=[UIColor whiteColor].CGColor;
    [self.view.layer addSublayer:Mylayer];

    UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    rightButton.frame = CGRectMake(SelfWidth - , SelfHeight - , , );
    [rightButton setTitle:@"使用照片" forState:UIControlStateNormal];
    [rightButton setTintColor:[UIColor whiteColor]];
    [rightButton addTarget:self action:@selector(rightButton) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:rightButton];

    // Do any additional setup after loading the view.
}

-(void)rightButton{

    //截取照片，截取到自定义框内的照片
    imageIm = [self image:imageIm scaleToSize:CGSizeMake(SelfWidth, SelfHeight)];
    //应为在展开相片时放大的两倍，截取时也要放大两倍
    imageIm = [self imageFromImage:imageIm inRect:CGRectMake(*, (SelfHeight - (SelfWidth - ) /1.6)/*, (SelfWidth - )* , (SelfWidth - )/1.6*)];

    //将图片存储到相册
     UIImageWriteToSavedPhotosAlbum(imageIm, self, nil, nil);

   //截取之后将图片显示在照相时页面，和拍摄时的照片进行像素对比
    UIImageView *imageView =[[UIImageView alloc] initWithFrame:CGRectMake(, (SelfHeight - (SelfWidth - ) /1.6)/  + , SelfWidth -  , (SelfWidth - )/1.6)];
    imageView.image = imageIm;
    [self.view addSubview:imageView];

}

//截取图片
-(UIImage*)image:(UIImage *)imageI scaleToSize:(CGSize)size{
   /*
    UIGraphicsBeginImageContextWithOptions(CGSize size, BOOL opaque, CGFloat scale)
    CGSize size：指定将来创建出来的bitmap的大小
    BOOL opaque：设置透明YES代表透明，NO代表不透明
    CGFloat scale：代表缩放,0代表不缩放
    创建出来的bitmap就对应一个UIImage对象
    */
    UIGraphicsBeginImageContextWithOptions(size, NO, 2.0); //此处将画布放大两倍，这样在retina屏截取时不会影响像素

    [imageI drawInRect:CGRectMake(, , size.width, size.height)];

    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return scaledImage;
}
-(UIImage *)imageFromImage:(UIImage *)imageI inRect:(CGRect)rect{

    CGImageRef sourceImageRef = [imageI CGImage];

    CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef, rect);

    UIImage *newImage = [UIImage imageWithCGImage:newImageRef];

    return newImage;
}

-(void)back{
    [self dismissViewControllerAnimated:NO completion:nil];
}

完整代码下载，GitHub：https://github.com/micaimanong/CameraDema