我简单说一下我写的这个例子大概有4种实现方式:
- 1.Core Image （里面使用了两种方法,但是两种方法都不是很好，好用内存相当大，有肯能存在内存泄露，及其不推荐）
- 2.GPUImage （第三方库已经加入到工程中，消耗内存也不小）
- 3.系统的方法 要使用vImageBoxConvolve_ARGB8888
- 4.rt_tintedImageWithColor（一个第三方库，具体地址忘记了） 主要利用CGContextSetFillColorWithColor和系统方法结合
- 5.还有就是模糊图片 加上半透明view 开销最小因为没有用代码实现模糊
主要推荐3\4\5 可以自己看一下内存占用率。
<b>下面是效果图：</b>
BlurImage.gif
下面是主要代码：
+ (UIImage *)blurryImage:(UIImage *)image withBlurLevel:(CGFloat)blur {
if 0
//图片没有铺满 真心不知道怎么回事
if (image == nil) {
return nil;
}
CIImage *inputImage = [CIImage imageWithCGImage:image.CGImage];
CGAffineTransform transform = CGAffineTransformIdentity;
CIFilter *clampFilter = [CIFilter filterWithName:@"CIAffineClamp"];
[clampFilter setValue:inputImage forKey:@"inputImage"];
[clampFilter setValue:[NSValue valueWithBytes:&transform objCType:@encode(CGAffineTransform)] forKey:@"inputTransform"];
CIFilter *gaussianBlurFilter = [CIFilter filterWithName: @"CIGaussianBlur"];
[gaussianBlurFilter setValue:clampFilter.outputImage forKey: @"inputImage"];
[gaussianBlurFilter setValue:[NSNumber numberWithFloat:blur] forKey:@"inputRadius"];
// CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"
// keysAndValues:kCIInputImageKey, inputImage, nil];
// [filter setValue:[NSNumber numberWithFloat:blur] forKey:@"inputRadius"];
CIImage *outputImage = gaussianBlurFilter.outputImage;
CGRect rect = [outputImage extent];
rect.origin.x += (rect.size.width - image.size.width ) / 2;
rect.origin.y += (rect.size.height - image.size.height) / 2;
rect.size = image.size;
CIImage* croppedImage = [outputImage imageByCroppingToRect:rect];
UIImage * blurryImage = [UIImage imageWithCIImage:croppedImage];
//该方法有内存泄露的问题
// CIContext *context = [CIContext contextWithOptions:nil]; // save it to self.context
// CGImageRef outImage = [context createCGImage:outputImage fromRect:rect];
// UIImage * blurryImage = [UIImage imageWithCGImage:outImage];
// CGImageRelease(outImage);
return blurryImage;
#else
//而且不建议每次都建立context
CIImage *inputImage = [CIImage imageWithCGImage:image.CGImage];
CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"
keysAndValues:kCIInputImageKey, inputImage,
@"inputRadius", @(blur), nil];
CIImage *outputImage = filter.outputImage;
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef outImage = [context createCGImage:outputImage fromRect:[outputImage extent]];
UIImage *returnImage = [UIImage imageWithCGImage:outImage];
CGImageRelease(outImage);
return returnImage;
#endif
}
+ (UIImage *)blurrymage:(UIImage *)image withBlurLevel:(CGFloat)blur {
if (blur < 0.f || blur > 1.f) {
blur = 0.5f;
}
int boxSize = (int)(blur * 100);
boxSize = boxSize - (boxSize % 2) + 1;
CGImageRef img = image.CGImage;
vImage_Buffer inBuffer, outBuffer;
vImage_Error error;
void *pixelBuffer;
CGDataProviderRef inProvider = CGImageGetDataProvider(img);
CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
inBuffer.width = CGImageGetWidth(img);
inBuffer.height = CGImageGetHeight(img);
inBuffer.rowBytes = CGImageGetBytesPerRow(img);
inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
pixelBuffer = malloc(CGImageGetBytesPerRow(img) *
CGImageGetHeight(img));
if(pixelBuffer == NULL)
NSLog(@"No pixelbuffer");
outBuffer.data = pixelBuffer;
outBuffer.width = CGImageGetWidth(img);
outBuffer.height = CGImageGetHeight(img);
outBuffer.rowBytes = CGImageGetBytesPerRow(img);
error = vImageBoxConvolve_ARGB8888(&inBuffer,
&outBuffer,
NULL,0,0,boxSize,boxSize,NULL,kvImageEdgeExtend);
if (error) {
NSLog(@"error from convolution %ld", error);
}
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef ctx = CGBitmapContextCreate(
outBuffer.data,
outBuffer.width,
outBuffer.height,
8,
outBuffer.rowBytes,
colorSpace,
kCGImageAlphaNoneSkipLast);
CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
//clean up
CGContextRelease(ctx);
CGColorSpaceRelease(colorSpace);
free(pixelBuffer);
CFRelease(inBitmapData);
CGImageRelease(imageRef);
return returnImage;
}
-(UIImage*)rt_tintedImageWithColor:(UIColor*)color rect:(CGRect)rect level:(CGFloat)level {
CGRect imageRect = CGRectMake(0.0f, 0.0f, self.size.width, self.size.height);
UIGraphicsBeginImageContextWithOptions(imageRect.size, NO, self.scale);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[self drawInRect:imageRect];
CGContextSetFillColorWithColor(ctx, [color CGColor]);
CGContextSetAlpha(ctx, level);
CGContextSetBlendMode(ctx, kCGBlendModeSourceAtop);
CGContextFillRect(ctx, rect);
CGImageRef imageRef = CGBitmapContextCreateImage(ctx);
UIImage *darkImage = [UIImage imageWithCGImage:imageRef
scale:self.scale
orientation:self.imageOrientation];
CGImageRelease(imageRef);
UIGraphicsEndImageContext();
return darkImage;
}
其他的可以看一下这个demo:
https://github.com/WonderC/BlurImageMethodDemo
