iOS view模糊背景

標籤：

 1 /** 2  *  模糊背景 3  * 4  *  @param image    需要模糊的圖片 5  *  @param blur     高斯模糊的值 6  * 7  *  @return 8  */ 9 - (UIImage *)blurryImage:(UIImage *)image withBlurLevel:(CGFloat)blur10 {11     if ((blur < 0.0f) || (blur > 1.0f)) {12         blur = 0.5f;13     }14     15     int boxSize = (int)(blur * 100);16     boxSize -= (boxSize % 2) + 1;17     18     CGImageRef img = image.CGImage;19     20     vImage_Buffer inBuffer, outBuffer;21     vImage_Error error;22     void *pixelBuffer;23     24     CGDataProviderRef inProvider = CGImageGetDataProvider(img);25     CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);26     27     inBuffer.width = CGImageGetWidth(img);28     inBuffer.height = CGImageGetHeight(img);29     inBuffer.rowBytes = CGImageGetBytesPerRow(img);30     inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);31     32     pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));33     34     outBuffer.data = pixelBuffer;35     outBuffer.width = CGImageGetWidth(img);36     outBuffer.height = CGImageGetHeight(img);37     outBuffer.rowBytes = CGImageGetBytesPerRow(img);38     39     error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);40     41     CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();42     CGContextRef ctx = CGBitmapContextCreate(outBuffer.data, outBuffer.width, outBuffer.height, 8, outBuffer.rowBytes, colorSpace, CGImageGetBitmapInfo(image.CGImage));43     44     CGImageRef imageRef = CGBitmapContextCreateImage (ctx);45     UIImage *returnImage = [UIImage imageWithCGImage:imageRef];46     47     //clean up48     CGContextRelease(ctx);49     CGColorSpaceRelease(colorSpace);50     51     free(pixelBuffer);52     CFRelease(inBitmapData);53     54     CGColorSpaceRelease(colorSpace);55     CGImageRelease(imageRef);56     57     return returnImage;58 }

 

iOS view模糊背景