[英]Image is rotated 90 degrees when using clipToMask
我试图裁剪用相机拍摄的图像的一部分。 这是我的剪辑代码:
- (UIImage*) maskImage:(UIImage *)image {
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
UIImage *maskImage = [UIImage imageNamed:@"mask3.png"];
CGImageRef maskImageRef = [maskImage CGImage];
// create a bitmap graphics context the size of the image
CGContextRef mainViewContentContext = CGBitmapContextCreate (NULL, maskImage.size.width, maskImage.size.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
if (mainViewContentContext==NULL)
return NULL;
CGFloat ratio = 0;
ratio = maskImage.size.width/ image.size.width;
if(ratio * image.size.height < maskImage.size.height) {
ratio = maskImage.size.height/ image.size.height;
}
CGRect rect1 = {{0, 0}, {maskImage.size.width, maskImage.size.height}};
CGRect rect2 = {{-((image.size.width*ratio)-maskImage.size.width)/2 , -((image.size.height*ratio)-maskImage.size.height)/2}, {image.size.width*ratio, image.size.height*ratio}};
CGContextClipToMask(mainViewContentContext, rect1, maskImageRef);
CGContextDrawImage(mainViewContentContext, rect2, image.CGImage);
// Create CGImageRef of the main view bitmap content, and then
// release that bitmap context
CGImageRef newImage = CGBitmapContextCreateImage(mainViewContentContext);
CGContextRelease(mainViewContentContext);
UIImage *theImage = [UIImage imageWithCGImage:newImage];
CGImageRelease(newImage);
// return the image
return theImage;
}
我在我的viewcontroller中的captureNow方法中调用上述方法。 我正在使用AVFoundation捕获静止图像:
-(void) captureNow
{
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in 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: %@", stillImageOutput);
[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
{
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
[testImageView setImage:[self maskImage:image]];
self.firstPieceView.frame = CGRectMake(0, 0, 320, 480);
self.firstPieceView.contentMode = UIViewContentModeScaleAspectFill;
// self.firstPieceView.image = image;
// [firstPieceView setNeedsDisplay];
NSLog(@"self.firstPiece.frame is %@", NSStringFromCGRect(self.firstPieceView.frame));
// [myView becomeFirstResponder];
}];
self.previewParentView.hidden = YES;
self.photoBtn.hidden=YES;
self.imageMask.hidden = NO;
//add the gesture after taking the first image.
[myView addGestureRecognizersToPiece:self.myView];
}
出于某些原因,我在裁剪图像时总是将其旋转90度。 有谁知道为什么以及如何解决这个问题? 提前致谢。
这里是将图像旋转到90度的替代解决方案,其代码如下:
yourImageView.transform = CGAffineTransformMakeRotation(3.14159265/2);
当您当时想要共享或保存图片时,只需将图像旋转90度,如果需要,还可以旋转180度。
如果我有其他想法,这是替代解决方案,然后我将再次发布...希望,这对您有帮助...
:)
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