CoreImage的内存泄漏

Question

我已经创建了如下模糊图像：

//Blur the UIImage
CIImage *imageToBlur = [CIImage imageWithCGImage:viewImage.CGImage];
CIFilter *gaussianBlurFilter = [CIFilter filterWithName: @"CIGaussianBlur"];
[gaussianBlurFilter setValue:imageToBlur forKey: @"inputImage"];
[gaussianBlurFilter setValue:[NSNumber numberWithFloat: 2] forKey: @"inputRadius"];
CIImage *resultImage = [gaussianBlurFilter valueForKey: @"outputImage"];
CIImage *finalImage = [resultImage imageByCroppingToRect:CGRectMake(0, 10, self.view.bounds.size.width, self.view.bounds.size.height)];

//create UIImage from filtered image
UIImage *blurrredImage = [[UIImage alloc] initWithCIImage:finalImage];

CIFilter *colorMatrixFilter = [CIFilter filterWithName:@"CIColorMatrix"];
[colorMatrixFilter setDefaults];
[colorMatrixFilter setValue:finalImage forKey:kCIInputImageKey];
[colorMatrixFilter setValue:[CIVector vectorWithX:0.25 Y:0 Z:0 W:0] forKey:@"inputRVector"];
[colorMatrixFilter setValue:[CIVector vectorWithX:0 Y:0.35 Z:0 W:0] forKey:@"inputGVector"];
[colorMatrixFilter setValue:[CIVector vectorWithX:0 Y:0 Z:0.4 W:0] forKey:@"inputBVector"];
[colorMatrixFilter setValue:[CIVector vectorWithX:0 Y:0 Z:0 W:1] forKey:@"inputAVector"];

// Get the output image recipe
CIImage *outputImage = [colorMatrixFilter outputImage];

// Create the context and instruct CoreImage to draw the output image recipe into a CGImage
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef cgimg = [context createCGImage:outputImage fromRect:[outputImage extent]];
blurrredImage = [UIImage imageWithCGImage:cgimg];


CGImageRelease(cgimg);

//Place the UIImage in a UIImageView
UIImageView *newView = [[UIImageView alloc] initWithFrame:self.view.bounds];
newView.image = blurrredImage;

//insert blur UIImageView below transparent view inside the blur image container
[blurContainerView insertSubview:newView belowSubview:transparentView];

我已经释放了CGImageRef，但仍然在

CGImageRef cgimg = [context createCGImage:outputImage fromRect:[outputImage extent]];

我也被推荐了所有其他相关的问题，并实现了提供的答案仍然得到内存泄漏

已使用@autoreleasepool {}并尝试将对象设置为空

context = nil;
outputImage = nil;
gaussianBlurFilter = nil;
viewImage = nil;

在此之前

CGImageRelease(cgimg);

尽管如此，它仍然显示了内存泄漏，说明如下。ARC已打开，ios版本为6.1和7

责任库是: CoreImage责任调用者是: CI::GLESContext::program_for_name(__CFString const*)

有人能建议我如何解决这个内存泄漏问题吗？

提前感谢您的帮助。

Answer 1

所有的核心框架都使用C语言，而不是Objective-C。你必须手动进行内存管理，ARC在这方面帮不了你太多，除非将一些(免费桥接的)引用的所有权从Core转移到Objective-C对象。你真的应该阅读Apple documentation来理解你需要做什么。

简而言之，设置对nil的引用(在C中应该是NULL )会给您留下一个悬空指针和内存泄漏。

Answer 2

问题就是常量调用

[CIContext contextWithOptions:nil]

我建议在您的类中创建一个CIContext属性：

@property (retain, nonatomic) CIContext *context;

并且仅在上下文为nil时实例化它

if( self.context == nil ) {
    self.context = [CIContext contextWithOptions:nil];
}