iOS开发之图片模糊效果的五种实现代码

- (void)toolbarStyle{

 CGRect toolbarRect = CGRectMake(0, 0,ScreenW/2,ScreenH);
 UIToolbar *toolbar = [[UIToolbar alloc] initWithFrame:toolbarRect];
 /*
  * UIBarStyleDefault   = 0,
  * UIBarStyleBlack   = 1,
  * UIBarStyleBlackOpaque  = 1, // Deprecated. Use UIBarStyleBlack
  * UIBarStyleBlackTranslucent = 2, // Deprecated. Use UIBarStyleBlack and set the translucent property to YES
  */
 toolbar.barStyle = UIBarStyleBlack;

 [self.myImageView addSubview:toolbar];
}

- (void)uivisualEffectViewStyle{
 /* NS_ENUM_AVAILABLE_IOS(8_0)
  * UIBlurEffectStyleExtraLight,//额外亮度，（高亮风格）
  * UIBlurEffectStyleLight,//亮风格
  * UIBlurEffectStyleDark,//暗风格
  * UIBlurEffectStyleExtraDark __TVOS_AVAILABLE(10_0) __IOS_PROHIBITED __WATCHOS_PROHIBITED,
  * UIBlurEffectStyleRegular NS_ENUM_AVAILABLE_IOS(10_0), // Adapts to user interface style
  * UIBlurEffectStyleProminent NS_ENUM_AVAILABLE_IOS(10_0), // Adapts to user interface style

  */
 //实现模糊效果
 UIBlurEffect *effect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
 //毛玻璃视图
 UIVisualEffectView *effectView = [[UIVisualEffectView alloc] initWithEffect:effect];;
 effectView.frame = CGRectMake(0, 0, ScreenW/2, ScreenH);

 [self.myImageView addSubview:effectView];
}

- (UIImage *)coreBlurImage:(UIImage *)image withBlurNumber:(CGFloat)blur{

 CIContext *context = [CIContext contextWithOptions:nil];
 CIImage *inputImage = [CIImage imageWithCGImage:image.CGImage];
 //设置filter
 CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
 [filter setValue:inputImage forKey:kCIInputImageKey];
 [filter setValue:@(blur) forKey:@"inputRadius"];
 //模糊图片
 CIImage *result = [filter valueForKey:kCIOutputImageKey];
 CGImageRef outImage = [context createCGImage:result fromRect:[result extent]];
 UIImage *blurImage = [UIImage imageWithCGImage:outImage];
 CGImageRelease(outImage);
 return blurImage;

}

- (UIImage *)GPUImageStyleWithImage:(UIImage *)image{

 GPUImageGaussianBlurFilter *filter = [[GPUImageGaussianBlurFilter alloc] init];
 filter.blurRadiusInPixels = 10.0;//值越大，模糊度越大
 UIImage *blurImage = [filter imageByFilteringImage:image];
 return blurImage;

}

- (UIImage *)boxblurImage:(UIImage *)image withBlurNumber:(CGFloat)blur
{
 if (blur < 0.f || blur > 1.f) {
  blur = 0.5f;
 }

 int boxSize = (int)(blur * 40);
 boxSize = boxSize - (boxSize % 2) + 1;
 CGImageRef img = image.CGImage;
 vImage_Buffer inBuffer, outBuffer;
 vImage_Error error;
 void *pixelBuffer;

 //从CGImage中获取数据
 CGDataProviderRef inProvider = CGImageGetDataProvider(img);
 CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);

 //设置从CGImage获取对象的属性
 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);
 CGColorSpaceRelease(colorSpace);
 CGImageRelease(imageRef);
 return returnImage;

}

[effectview removeFromSuperview];