iOS 自定义相机

WechatIMG2.jpeg

WechatIMG1.jpeg

自定义相机，实现上面两张图片的功能。

首先实现相机的基本功能：数据流的输入和输出

定义属性：

//捕获设备，通常是前置摄像头，后置摄像头，麦克风（音频输入）
@property(nonatomic)AVCaptureDevice *device;

//AVCaptureDeviceInput 代表输入设备，他使用AVCaptureDevice 来初始化
@property(nonatomic)AVCaptureDeviceInput *input;

//当启动摄像头开始捕获输入
@property(nonatomic)AVCaptureMetadataOutput *output;

@property (nonatomic)AVCaptureStillImageOutput *ImageOutPut;

//session：由他把输入输出结合在一起，并开始启动捕获设备（摄像头）
@property(nonatomic)AVCaptureSession *session;

//图像预览层，实时显示捕获的图像
@property(nonatomic)AVCaptureVideoPreviewLayer *previewLayer;

数据的获取和展示：

- (void)customCamera{
    self.view.backgroundColor = [UIColor whiteColor];
    
    //使用AVMediaTypeVideo 指明self.device代表视频，默认使用后置摄像头进行初始化
    self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //使用设备初始化输入
    self.input = [[AVCaptureDeviceInput alloc]initWithDevice:self.device error:nil];
    //生成输出对象
    self.output = [[AVCaptureMetadataOutput alloc]init];
    self.ImageOutPut = [[AVCaptureStillImageOutput alloc] init];
    //生成会话，用来结合输入输出
    self.session = [[AVCaptureSession alloc]init];
    if ([self.session canSetSessionPreset:AVCaptureSessionPresetHigh]) {
        self.session.sessionPreset = AVCaptureSessionPresetHigh;
    }
    if ([self.session canAddInput:self.input]) {
        [self.session addInput:self.input];
    }
    if ([self.session canAddOutput:self.ImageOutPut]) {
        [self.session addOutput:self.ImageOutPut];
    }
    //使用self.session，初始化预览层，self.session负责驱动input进行信息的采集，layer负责把图像渲染显示
    self.previewLayer = [[AVCaptureVideoPreviewLayer alloc]initWithSession:self.session];
    //228x362
//    self.previewLayer.frame = CGRectMake((kScreenWidth - 228.0 / 375.0) / 2, (kScreenHeight - 362.0 / 667.0) / 2, 228.0 / 375.0, 362.0 / 667.0);
    self.previewLayer.frame = CGRectMake(0, 0, kScreenWidth, kScreenHeight);
    self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    [self.view.layer addSublayer:self.previewLayer];
    
    //开始启动
    [self.session startRunning];
    if ([_device lockForConfiguration:nil]) {
        if ([_device isFlashModeSupported:AVCaptureFlashModeAuto]) {
            [_device setFlashMode:AVCaptureFlashModeAuto];
        }
        //自动白平衡
        if ([_device isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeAutoWhiteBalance]) {
            [_device setWhiteBalanceMode:AVCaptureWhiteBalanceModeAutoWhiteBalance];
        }
        [_device unlockForConfiguration];
    }
}

此时已经生成了一个全屏的相机。要实现图1的效果，需要在预览层self.previewLayer上面添加一个图片（四周0.7透明度，中间全透明）以及拍摄和取消两个按钮。

    _bgImage = [[UIImageView alloc] init];
    [self.view addSubview:_bgImage];
    [_bgImage mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.mas_equalTo(self.view);
    }];
    _bgImage.image = [UIImage imageNamed:@"Mine_camera_bg"];
    _bgImage.alpha = 0.7;
    _bgImage.userInteractionEnabled = YES;
    
    _PhotoButton = [UIButton buttonWithType:UIButtonTypeCustom];
    [_PhotoButton setImage:[UIImage imageNamed:@"Mine_camera_button"] forState: UIControlStateNormal];
//    [_PhotoButton setImage:[UIImage imageNamed:@"Mine_camera_button"] forState:UIControlStateNormal];
    [_PhotoButton addTarget:self action:@selector(shutterCamera) forControlEvents:UIControlEventTouchUpInside];
    [_bgImage addSubview:_PhotoButton];
    [_PhotoButton mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerX.mas_equalTo(_bgImage.mas_centerX);
        make.bottom.mas_offset(-41);
        make.size.mas_equalTo(CGSizeMake(70, 70));
    }];
    
    UIButton *quitBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    [quitBtn setTitle:@"取消" forState:UIControlStateNormal];
    [quitBtn setTitleColor:Colorffffff forState:UIControlStateNormal];
    [quitBtn.titleLabel setFont:[UIFont systemFontOfSize:16]];
    [_bgImage addSubview:quitBtn];
    [quitBtn mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerY.mas_equalTo(_PhotoButton.mas_centerY);
        make.right.mas_equalTo(_PhotoButton.mas_left).offset(-60);
        make.size.mas_equalTo(CGSizeMake(60, 50));
    }];
    WEAKSELF
    [quitBtn addTapBlock:^(id obj) {
        STRONGSELF
        [strongSelf dismissViewControllerAnimated:YES completion:^{
            
        }];
    }];

点击拍摄，生成图片。

- (void) shutterCamera
{
    AVCaptureConnection * videoConnection = [self.ImageOutPut connectionWithMediaType:AVMediaTypeVideo];
    if (!videoConnection) {
        NSLog(@"take photo failed!");
        return;
    }
    videoConnection.preferredVideoStabilizationMode = AVCaptureVideoStabilizationModeStandard;
    
    [self.ImageOutPut captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
        if (imageDataSampleBuffer == NULL) {
            return;
        }
        NSData * imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
        self.image = [UIImage imageWithData:imageData];
        [self.session stopRunning];
        //显示预览层
        [self showImageAction];
    }];
}

此时生成了一张全屏的图片，如果要实现图2的预览图片界面。需要把图片进行几步处理。

1.之前设置图像输出的时候，设置了AVCaptureSessionPresetHigh这个参数，意思是生成的图片质量是当前设备支持的最高设备，所以此时生成的图片的尺寸并不是屏幕的尺寸，例如我使用的8p,生成的图片的尺寸为1080*1992。所以第一步需要将图片的尺寸转换成屏幕尺寸。

2.然后在图片中截取和图1上面中间透明的一块图片。

3.将图片旋转90度，生成图2中横向的图片。

//将原来的图片尺寸更改为屏幕尺寸
    self.image = [self image:self.image scaleToSize:CGSizeMake(kScreenWidth, kScreenHeight)];
    //生成一个固定尺寸的图片
    CGSize oldImageSize = CGSizeMake(self.image.size.width * 3, self.image.size.height * 3);
    CGFloat newImageWidth = 228.0 / 375.0 * oldImageSize.width;
    CGFloat newImageHeight = 362.0 / 667.0 * oldImageSize.height;

    UIImage *scaleImage = [self imageFromImage:self.image inRect:CGRectMake((oldImageSize.width - newImageWidth) / 2, (oldImageSize.height - newImageHeight) / 2, newImageWidth, newImageHeight)];
    //旋转图片
    self.showImage = [scaleImage imageByRotateLeft90];

此时生成的self.showImage就是我们最终想要的图片。

上面代码用到的方法

//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, 3.0); //此处将画布放大三倍，这样在retina屏截取时不会影响像素
    
    [imageI drawInRect:CGRectMake(0, 0, size.width, size.height)];
    
    
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return scaledImage;
}

需要注意的是，在这里将画布放大了三倍，获得的图片尺寸虽然是屏幕的正常尺寸，但是在计算尺寸的时候要将宽和高都*3来计算。

-(UIImage *)imageFromImage:(UIImage *)imageI inRect:(CGRect)rect{
    
    CGImageRef sourceImageRef = [imageI CGImage];
    
    CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef, rect);
    
    UIImage *newImage = [UIImage imageWithCGImage:newImageRef];
    
    return newImage;
}

最后添加图2的UI就大功告成了。

最后，还有一些相机的功能。

切换摄像头

- (void)changeCamera{
    NSUInteger cameraCount = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo] count];
    if (cameraCount > 1) {
        NSError *error;
        
        CATransition *animation = [CATransition animation];
        
        animation.duration = .5f;
        
        animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
        
        animation.type = @"oglFlip";
        AVCaptureDevice *newCamera = nil;
        AVCaptureDeviceInput *newInput = nil;
        AVCaptureDevicePosition position = [[_input device] position];
        if (position == AVCaptureDevicePositionFront){
            newCamera = [self cameraWithPosition:AVCaptureDevicePositionBack];
            animation.subtype = kCATransitionFromLeft;
        }
        else {
            newCamera = [self cameraWithPosition:AVCaptureDevicePositionFront];
            animation.subtype = kCATransitionFromRight;
        }
        
        newInput = [AVCaptureDeviceInput deviceInputWithDevice:newCamera error:nil];
        [self.previewLayer addAnimation:animation forKey:nil];
        if (newInput != nil) {
            [self.session beginConfiguration];
            [self.session removeInput:_input];
            if ([self.session canAddInput:newInput]) {
                [self.session addInput:newInput];
                self.input = newInput;
                
            } else {
                [self.session addInput:self.input];
            }
            
            [self.session commitConfiguration];
            
        } else if (error) {
            NSLog(@"toggle carema failed, error = %@", error);
        }
        
    }
}

控制闪关灯开关

//- (void)FlashOn{
//    if ([_device lockForConfiguration:nil]) {
//        if (_isflashOn) {
//            if ([_device isFlashModeSupported:AVCaptureFlashModeOff]) {
//                [_device setFlashMode:AVCaptureFlashModeOff];
//                _isflashOn = NO;
//                [_flashButton setTitle:@"闪光灯关" forState:UIControlStateNormal];
//            }
//        }else{
//            if ([_device isFlashModeSupported:AVCaptureFlashModeOn]) {
//                [_device setFlashMode:AVCaptureFlashModeOn];
//                _isflashOn = YES;
//                [_flashButton setTitle:@"闪光灯开" forState:UIControlStateNormal];
//            }
//        }
//
//        [_device unlockForConfiguration];
//    }
//}

聚焦

- (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition)position{
    NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    for ( AVCaptureDevice *device in devices )
        if ( device.position == position ) return device;
    return nil;
}
- (void)focusGesture:(UITapGestureRecognizer*)gesture{
    CGPoint point = [gesture locationInView:gesture.view];
    [self focusAtPoint:point];
}
- (void)focusAtPoint:(CGPoint)point{
    CGSize size = self.view.bounds.size;
    CGPoint focusPoint = CGPointMake( point.y /size.height ,1-point.x/size.width );
    NSError *error;
    if ([self.device lockForConfiguration:&error]) {
        
        if ([self.device isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {
            [self.device setFocusPointOfInterest:focusPoint];
            [self.device setFocusMode:AVCaptureFocusModeAutoFocus];
        }
        
        if ([self.device isExposureModeSupported:AVCaptureExposureModeAutoExpose ]) {
            [self.device setExposurePointOfInterest:focusPoint];
            [self.device setExposureMode:AVCaptureExposureModeAutoExpose];
        }
        
        [self.device unlockForConfiguration];
        _focusView.center = point;
        _focusView.hidden = NO;
        [UIView animateWithDuration:0.3 animations:^{
            _focusView.transform = CGAffineTransformMakeScale(1.25, 1.25);
        }completion:^(BOOL finished) {
            [UIView animateWithDuration:0.5 animations:^{
                _focusView.transform = CGAffineTransformIdentity;
            } completion:^(BOOL finished) {
                _focusView.hidden = YES;
            }];
        }];
    }
    
}

Demo：https://github.com/Garrett-Gyz/CustomCamera

iOS 自定义相机

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