UIImage box blur creation category

UIImage+Blur.h

#import <UIKit/UIKit.h>

@interface UIImage (Blur)

- (UIImage *)boxBlur:(CGFloat)blurLevel depth:(NSUInteger)blurDepth;

@end

UIImage+Blur.m

#import "UIImage+Blur.h"
#import <float.h>

@import Accelerate;

@implementation UIImage (Blur)

- (UIImage *)boxBlur:(CGFloat)blurLevel depth:(NSUInteger)blurDepth {
    
    blurLevel = MIN(1.0, MAX(0.0, blurLevel));
    blurDepth = MAX(1,   MIN(100, blurDepth));
    
    int boxSize = (int)(blurLevel * 0.1 * MIN(self.size.width, self.size.height));
    boxSize = boxSize - (boxSize % 2) + 1;
    
    NSData *imageData = UIImagePNGRepresentation(self);
    UIImage *tmpImage = [UIImage imageWithData:imageData];
    
    CGImageRef img = tmpImage.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));
    
    outBuffer.data = pixelBuffer;
    outBuffer.width = CGImageGetWidth(img);
    outBuffer.height = CGImageGetHeight(img);
    outBuffer.rowBytes = CGImageGetBytesPerRow(img);
    
    for (NSUInteger index = 0; index < blurDepth; index++) {
        error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend)?:
                vImageBoxConvolve_ARGB8888(&outBuffer, &inBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
        
        if (error) {
            break;
        }
    }
    
    outBuffer = inBuffer;
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef ctx = CGBitmapContextCreate(outBuffer.data,
                                             outBuffer.width,
                                             outBuffer.height,
                                             8,
                                             outBuffer.rowBytes,
                                             colorSpace,
                                             kCGBitmapAlphaInfoMask & kCGImageAlphaPremultipliedLast);
    CGImageRef imageRef = CGBitmapContextCreateImage(ctx);
    UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
    
    CGContextRelease(ctx);
    CGColorSpaceRelease(colorSpace);
    free(pixelBuffer);
    CFRelease(inBitmapData);
    CGImageRelease(imageRef);
    
    return returnImage;
}

@end