我试图让我的应用程序以正确的方式创建 UIImage。
我的大部分代码都取自 Apple 示例...
@interface CameraManager () <AVCaptureVideoDataOutputSampleBufferDelegate>
@property (nonatomic, strong) CIContext *context;
@property (nonatomic, strong) AVCaptureDevice *rearCamera;
@end
@implementation CameraManager
- (id)init {
if ((self = [super init])) {
self.context = [CIContext contextWithOptions:nil];
[self setupCamera];
[self addStillImageOutput];
}
return self;
}
- (void)setupCamera
{
self.session = [[AVCaptureSession alloc] init];
[self.session beginConfiguration];
[self.session setSessionPreset:AVCaptureSessionPresetPhoto];
NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
self.rearCamera = nil;
for (AVCaptureDevice *device in devices) {
if (device.position == AVCaptureDevicePositionBack) {
self.rearCamera = device;
break;
}
}
NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:self.rearCamera error:&error];
[self.session addInput:input];
AVCaptureVideoDataOutput *dataOutput = [[AVCaptureVideoDataOutput alloc] init];
[dataOutput setAlwaysDiscardsLateVideoFrames:YES];
NSDictionary *options = @{(id)kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_32BGRA)};
[dataOutput setVideoSettings:options];
[dataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
[self.session addOutput:dataOutput];
[self.session commitConfiguration];
}
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
// grab the pixel buffer
CVPixelBufferRef pixelBuffer = (CVPixelBufferRef) CMSampleBufferGetImageBuffer(sampleBuffer);
// create a CIImage from it, rotate it and zero the origin
CIImage *image = [CIImage imageWithCVPixelBuffer:pixelBuffer];
if ([[UIApplication sharedApplication] statusBarOrientation] == UIInterfaceOrientationLandscapeLeft) {
image = [image imageByApplyingTransform:CGAffineTransformMakeRotation(M_PI)];
}
CGPoint origin = [image extent].origin;
image = [image imageByApplyingTransform:CGAffineTransformMakeTranslation(-origin.x, -origin.y)];
// set it as the contents of the UIImageView
CGImageRef cgImage = [self.context createCGImage:image fromRect:[image extent]];
UIImage *uiImage = [UIImage imageWithCGImage:cgImage];
[[NSNotificationCenter defaultCenter] postNotificationName:@"image" object:uiImage];
CGImageRelease(cgImage);
}
- (void)addStillImageOutput
{
[self setStillImageOutput:[[AVCaptureStillImageOutput alloc] init]];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey,nil];
[[self stillImageOutput] setOutputSettings:outputSettings];
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [self.stillImageOutput connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
[[self session] addOutput:[self stillImageOutput]];
}
- (void)captureStillImage
{
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in [[self stillImageOutput] connections]) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo]) {
videoConnection = connection;
break;
}
}
if (videoConnection) {
break;
}
}
NSLog(@"about to request a capture from: %@", [self stillImageOutput]);
[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
CFDictionaryRef exifAttachments = CMGetAttachment(imageSampleBuffer, kCGImagePropertyExifDictionary, NULL);
if (exifAttachments) {
NSLog(@"attachements: %@", exifAttachments);
} else {
NSLog(@"no attachments");
}
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[[NSNotificationCenter defaultCenter] postNotificationName:kImageCapturedSuccessfully object:image];
}];
}
这是我的相机管理器类代码。
我正在使用 OutputSampleBufferDelegate 显示相机的预览(出于各种原因)。
我正在使用会话输出来“拍照”。
该方法captureStillImage
是我要解决的问题。
照片是使用横向左方向的设备拍摄的(界面也是横向的)。
预览都显示了正确的方式,exif 数据也显示了正确的宽度和高度。(X = 3264,Y = 2448)。
但是当我显示 UIImage 时,它会逆时针旋转 90 度。图像的纵横比是正确的(即一切看起来都很好,圆圈仍然是圆圈)只是旋转。
我发现了几个声称可以解决此问题的类别。
我还发现了几个 StackOverflow 问题,其中的答案也声称可以修复它。
这些都不起作用。
有谁知道如何以正确的方式旋转这个东西?