模糊图片

@implementation UIImage (Blur)

-(UIImage *)boxblurImageWithBlur:(CGFloat)blur {

NSData *imageData = UIImageJPEGRepresentation(self, 1); // convert to jpeg

UIImage* destImage = [UIImage imageWithData:imageData];

if (blur < 0.f || blur > 1.f) {

blur = 0.5f;

}

int boxSize = (int)(blur * 40);

boxSize = boxSize - (boxSize % 2) + 1;

CGImageRef img = destImage.CGImage;

vImage_Buffer inBuffer, outBuffer;

vImage_Error error;

void *pixelBuffer;

//create vImage_Buffer with data from CGImageRef

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);

//create vImage_Buffer for output

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);

// Create a third buffer for intermediate processing

void *pixelBuffer2 = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));

vImage_Buffer outBuffer2;

outBuffer2.data = pixelBuffer2;

outBuffer2.width = CGImageGetWidth(img);

outBuffer2.height = CGImageGetHeight(img);

outBuffer2.rowBytes = CGImageGetBytesPerRow(img);

//perform convolution

error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer2, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);

if (error) {

NSLog(@"error from convolution %ld", error);

}

error = vImageBoxConvolve_ARGB8888(&outBuffer2, &inBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);

if (error) {

NSLog(@"error from convolution %ld", error);

}

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,

(CGBitmapInfo)kCGImageAlphaNoneSkipLast);

CGImageRef imageRef = CGBitmapContextCreateImage (ctx);

UIImage *returnImage = [UIImage imageWithCGImage:imageRef];

//clean up

CGContextRelease(ctx);

CGColorSpaceRelease(colorSpace);

free(pixelBuffer);

free(pixelBuffer2);

CFRelease(inBitmapData);

CGImageRelease(imageRef);

return returnImage;

}

//使用

for (NSUInteger i = 0; i < 20; i++) {

[blurImages_ addObject:[self.image boxblurImageWithBlur:factor]];

factor+=0.0;

}