UIImage Blur

UIImage+Blur.h

//
//  UIImage+Blur.h
//  HTTPLoaderTest
//
//  Created by masaki.fuke on 12/08/14.
//  Copyright (c) 2012年 masaki.fuke. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIImage (Blur)

-(UIImage *)blurImageWithPoint:(NSUInteger)point;
-(UIImage *)gaussianBlurImage;

@end

UIImage+Blur.m

//
//  UIImage+Blur.m
//  HTTPLoaderTest
//
//  Created by masaki.fuke on 12/08/14.
//  Copyright (c) 2012年 masaki.fuke. All rights reserved.
//

#import "UIImage+Blur.h"
#import <Accelerate/Accelerate.h>

static int16_t gaussianblur_kernel[13] = {
    1, 12, 66, 220, 495, 792, 924, 792, 495, 220, 66, 12, 1
};

@implementation UIImage (Blur)

-(UIImage *)blurImageWithPoint:(NSUInteger)point
{
    NSInteger index = point * 2 * self.scale + 1;
    int16_t kernel[index];
    for (NSInteger i = 0; i < index; i++) {
        kernel[i] = 1;
    }
    
    UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    [self drawAtPoint:CGPointZero];
    
    size_t width = CGBitmapContextGetWidth(ctx);
    size_t height = CGBitmapContextGetHeight(ctx);
    size_t bytesPerRow = CGBitmapContextGetBytesPerRow(ctx);
    
    UInt8 *data = CGBitmapContextGetData(ctx);
    
    vImage_Buffer src = {data, height, width, bytesPerRow};
    
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, kernel , index, 1, index, NULL, kvImageEdgeExtend);
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, kernel, 1, index, index, NULL, kvImageEdgeExtend);
    
    UIImage *blurImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return blurImage;
}

-(UIImage *)gaussianBlurImage
{
    UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    [self drawAtPoint:CGPointZero];
    
    size_t width = CGBitmapContextGetWidth(ctx);
    size_t height = CGBitmapContextGetHeight(ctx);
    size_t bitsPerComponent = CGBitmapContextGetBitsPerComponent(ctx);
    size_t bitsPerPixcel = CGBitmapContextGetBitsPerPixel(ctx);
    size_t bytesPerRow = CGBitmapContextGetBytesPerRow(ctx);

    NSLog(@"%ld, %ld, %ld, %ld, %ld", width, height, bitsPerComponent, bitsPerPixcel, bytesPerRow);
    
    UInt8 *data = CGBitmapContextGetData(ctx);
    
    vImage_Buffer src = {data, height, width, bytesPerRow};
    
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, gaussianblur_kernel, 13, 1, 4096, NULL, kvImageEdgeExtend);
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, gaussianblur_kernel, 1, 13, 4096, NULL, kvImageEdgeExtend);

    UIImage *blurImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return blurImage;
}

@end

UIImageBlur.h

//
//  UIImage+Blur.h
//  HTTPLoaderTest
//
//  Created by masaki.fuke on 12/08/14.
//  Copyright (c) 2012年 masaki.fuke. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIImage (Blur)

-(UIImage *)blurImageWithPoint:(NSUInteger)point;
-(UIImage *)gaussianBlurImage;

@end

UIImageBlur.m

//
//  UIImage+Blur.m
//  HTTPLoaderTest
//
//  Created by masaki.fuke on 12/08/14.
//  Copyright (c) 2012年 masaki.fuke. All rights reserved.
//

#import "UIImage+Blur.h"
#import <Accelerate/Accelerate.h>

static int16_t gaussianblur_kernel[13] = {
    1, 12, 66, 220, 495, 792, 924, 792, 495, 220, 66, 12, 1
};

@implementation UIImage (Blur)

-(UIImage *)blurImageWithPoint:(NSUInteger)point
{
    NSInteger index = point * 2 * self.scale + 1;
    int16_t kernel[index];
    for (NSInteger i = 0; i < index; i++) {
        kernel[i] = 1;
    }
    
    UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    [self drawAtPoint:CGPointZero];
    
    size_t width = CGBitmapContextGetWidth(ctx);
    size_t height = CGBitmapContextGetHeight(ctx);
    size_t bytesPerRow = CGBitmapContextGetBytesPerRow(ctx);
    
    UInt8 *data = CGBitmapContextGetData(ctx);
    
    vImage_Buffer src = {data, height, width, bytesPerRow};
    
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, kernel , index, 1, index, NULL, kvImageEdgeExtend);
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, kernel, 1, index, index, NULL, kvImageEdgeExtend);
    
    UIImage *blurImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return blurImage;
}

-(UIImage *)gaussianBlurImage
{
    UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    [self drawAtPoint:CGPointZero];
    
    size_t width = CGBitmapContextGetWidth(ctx);
    size_t height = CGBitmapContextGetHeight(ctx);
    size_t bitsPerComponent = CGBitmapContextGetBitsPerComponent(ctx);
    size_t bitsPerPixcel = CGBitmapContextGetBitsPerPixel(ctx);
    size_t bytesPerRow = CGBitmapContextGetBytesPerRow(ctx);

    UInt8 *data = CGBitmapContextGetData(ctx);
    
    vImage_Buffer src = {data, height, width, bytesPerRow};
    
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, gaussianblur_kernel, 13, 1, 4096, NULL, kvImageEdgeExtend);
    vImageConvolve_ARGB8888(&src, &src, NULL, 0, 0, gaussianblur_kernel, 1, 13, 4096, NULL, kvImageEdgeExtend);

    UIImage *blurImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return blurImage;
}

@end