加入 CoreImage.framework CoreGraphic.framework 等庫
在使用時引入:#import ,支持iOS 5.0 及以上。
-(void)show
{
UIImage* img = [self getBlurImage:[UIImage imageNamed:@"Default-568h.png"]];
[_bgImageView setImage:img];
}
-(UIImage*)getBlurImage:(UIImage*)image
{
return [self gaussBlur:0.2 andImage:image];
}
- (UIImage*)gaussBlur:(CGFloat)blurLevel andImage:(UIImage*)originImage
{
blurLevel = MIN(1.0, MAX(0.0, blurLevel));
//int boxSize = (int)(blurLevel * 0.1 * MIN(self.size.width, self.size.height));
int boxSize = 50;//模糊度。
boxSize = boxSize - (boxSize % 2) + 1;
NSData *imageData = UIImageJPEGRepresentation(originImage, 1);
UIImage *tmpImage = [UIImage imageWithData:imageData];
CGImageRef img = tmpImage.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));
outBuffer.data = pixelBuffer;
outBuffer.width = CGImageGetWidth(img);
outBuffer.height = CGImageGetHeight(img);
outBuffer.rowBytes = CGImageGetBytesPerRow(img);
NSInteger windowR = boxSize/2;
CGFloat sig2 = windowR / 3.0;
if(windowR>0){ sig2 = -1/(2*sig2*sig2); }
int16_t *kernel = (int16_t*)malloc(boxSize*sizeof(int16_t));
int32_t sum = 0;
for(NSInteger i=0; i kernel[i] = 255*exp(sig2*(i-windowR)*(i-windowR)); sum += kernel[i]; } free(kernel); // convolution error = vImageConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, kernel, boxSize, 1, sum, NULL, kvImageEdgeExtend); error = vImageConvolve_ARGB8888(&outBuffer, &inBuffer, NULL, 0, 0, kernel, 1, boxSize, sum, NULL, kvImageEdgeExtend); outBuffer = inBuffer; if (error) { //NSLog(@"error from convolution %ld", error); } CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef ctx = CGBitmapContextCreate(outBuffer.data, outBuffer.width, outBuffer.height, 8, outBuffer.rowBytes, colorSpace, kCGBitmapAlphaInfoMask & kCGImageAlphaNoneSkipLast); CGImageRef imageRef = CGBitmapContextCreateImage(ctx); UIImage *returnImage = [UIImage imageWithCGImage:imageRef]; //clean up CGContextRelease(ctx); CGColorSpaceRelease(colorSpace); free(pixelBuffer); CFRelease(inBitmapData); CGImageRelease(imageRef); return returnImage; }