- (UIImage *)blurredImageWithRadius:iterations:tintColor: assumes image is in ARGB format

[CristianoCastro]

- (UIImage *)blurredImageWithRadius:iterations:tintColor: assumes image is in ARGB format, leading to crashes (EXEC_BAD_ACCESS) if image is not in that format.

You can reproduce with this example that uses a 8bit per pixel png indexed image:

UIImage *img = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://data3.whicdn.com/images/84761236/large.png"]]];
[img blurredImageWithRadius:10 iterations:10 tintColor:nil];

[nchrys]

I have the same problem! does anyone know some workaround?

[ogoldfinger]

me too

[gresrun]

Here's my solution which converts non-ARGB8888 images into ARGB8888:

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


#pragma mark UIImage+Blur Implementation
@implementation UIImage (Blur)

- (UIImage *)blurredImageWithRadius:(CGFloat)radius iterations:(NSUInteger)iterations tintColor:(UIColor *)tintColor {
    // Image must be nonzero size
    if (floorf(self.size.width) * floorf(self.size.height) <= 0.0f) {
        return self;
    }
    // Box size must be an odd integer
    int boxSize = radius * self.scale;
    if (boxSize % 2 == 0) {
        boxSize++;
    }
    // Create image buffers
    CGImageRef imageRef = self.CGImage;
    // DEBUG
//    CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
//    CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
//    NSLog(@"\n"
//          "CGImageGetHeight: %d\n"
//          "CGImageGetWidth:  %d\n"
//          "CGImageGetColorSpace: %@\n"
//          "CGImageGetBitsPerPixel:     %d\n"
//          "CGImageGetBitsPerComponent: %d\n"
//          "CGImageGetBytesPerRow:      %d\n"
//          "CGImageGetBitmapInfo: 0x%.8X\n"
//          "  kCGBitmapAlphaInfoMask     = %s\n"
//          "  kCGBitmapFloatComponents   = %s\n"
//          "  kCGBitmapByteOrderMask     = 0x%.8X\n"
//          "  kCGBitmapByteOrderDefault  = %s\n"
//          "  kCGBitmapByteOrder16Little = %s\n"
//          "  kCGBitmapByteOrder32Little = %s\n"
//          "  kCGBitmapByteOrder16Big    = %s\n"
//          "  kCGBitmapByteOrder32Big    = %s\n"
//          "CGImageGetAlphaInfo: 0x%.8X\n"
//          "  kCGImageAlphaNone               = %s\n"
//          "  kCGImageAlphaPremultipliedLast  = %s\n"
//          "  kCGImageAlphaPremultipliedFirst = %s\n"
//          "  kCGImageAlphaLast               = %s\n"
//          "  kCGImageAlphaFirst              = %s\n"
//          "  kCGImageAlphaNoneSkipLast       = %s\n"
//          "  kCGImageAlphaNoneSkipFirst      = %s\n"
//          "  kCGImageAlphaOnly               = %s\n",
//          (int)CGImageGetWidth(imageRef),
//          (int)CGImageGetHeight(imageRef),
//          CGImageGetColorSpace(imageRef),
//          (int)CGImageGetBitsPerPixel(imageRef),
//          (int)CGImageGetBitsPerComponent(imageRef),
//          (int)CGImageGetBytesPerRow(imageRef),
//          (unsigned)bitmapInfo,
//          (bitmapInfo & kCGBitmapAlphaInfoMask)     ? "YES" : "NO",
//          (bitmapInfo & kCGBitmapFloatComponents)   ? "YES" : "NO",
//          (bitmapInfo & kCGBitmapByteOrderMask),
//          ((bitmapInfo & kCGBitmapByteOrderMask) == kCGBitmapByteOrderDefault)  ? "YES" : "NO",
//          ((bitmapInfo & kCGBitmapByteOrderMask) == kCGBitmapByteOrder16Little) ? "YES" : "NO",
//          ((bitmapInfo & kCGBitmapByteOrderMask) == kCGBitmapByteOrder32Little) ? "YES" : "NO",
//          ((bitmapInfo & kCGBitmapByteOrderMask) == kCGBitmapByteOrder16Big)    ? "YES" : "NO",
//          ((bitmapInfo & kCGBitmapByteOrderMask) == kCGBitmapByteOrder32Big)    ? "YES" : "NO",
//          (unsigned)alphaInfo,
//          (alphaInfo == kCGImageAlphaNone)               ? "YES" : "NO",
//          (alphaInfo == kCGImageAlphaPremultipliedLast)  ? "YES" : "NO",
//          (alphaInfo == kCGImageAlphaPremultipliedFirst) ? "YES" : "NO",
//          (alphaInfo == kCGImageAlphaLast)               ? "YES" : "NO",
//          (alphaInfo == kCGImageAlphaFirst)              ? "YES" : "NO",
//          (alphaInfo == kCGImageAlphaNoneSkipLast)       ? "YES" : "NO",
//          (alphaInfo == kCGImageAlphaNoneSkipFirst)      ? "YES" : "NO",
//          (alphaInfo == kCGImageAlphaOnly)               ? "YES" : "NO"
//    );
    // END DEBUG
    if (![self isARGB8888:imageRef]) {
        // Convert to ARGB if it isn't
        NSLog(@"Converting image to ARGB8888");
        CGContextRef ctx = [self createARGBBitmapContextFromImage:imageRef];
        CGRect rect = {{0, 0}, {CGImageGetWidth(imageRef), CGImageGetHeight(imageRef)}};
        // Draw the image to the bitmap context. Once we draw, the memory
        // allocated for the context for rendering will then contain the
        // raw image data in the desired color space and byte order
        CGContextDrawImage(ctx, rect, imageRef);
        imageRef = CGBitmapContextCreateImage(ctx);
        CGContextRelease(ctx);
    }
    vImage_Buffer buffer1, buffer2;
    buffer1.width = buffer2.width = CGImageGetWidth(imageRef);
    buffer1.height = buffer2.height = CGImageGetHeight(imageRef);
    buffer1.rowBytes = buffer2.rowBytes = CGImageGetBytesPerRow(imageRef);
    CFIndex bytes = buffer1.rowBytes * buffer1.height;
    buffer1.data = malloc(bytes);
    buffer2.data = malloc(bytes);

    // Create temp buffer
    void *tempBuffer = malloc(vImageBoxConvolve_ARGB8888(&buffer1, &buffer2, NULL, 0, 0, boxSize, boxSize,
                                                         NULL, kvImageEdgeExtend + kvImageGetTempBufferSize));

    // Copy image data
    CFDataRef dataSource = CGDataProviderCopyData(CGImageGetDataProvider(imageRef));
    memcpy(buffer1.data, CFDataGetBytePtr(dataSource), bytes);
    CFRelease(dataSource);

    for (int i = 0; i < iterations; i++) {
        // Perform blur
        vImageBoxConvolve_ARGB8888(&buffer1, &buffer2, tempBuffer, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);

        // Swap buffers
        void *temp = buffer1.data;
        buffer1.data = buffer2.data;
        buffer2.data = temp;
    }

    // Free buffers
    free(buffer2.data);
    free(tempBuffer);

    // Create image context from buffer
    CGContextRef ctx = CGBitmapContextCreate(buffer1.data, buffer1.width, buffer1.height,
                                             8, buffer1.rowBytes, CGImageGetColorSpace(imageRef),
                                             CGImageGetBitmapInfo(imageRef));

    // Apply tint
    if (tintColor && ![tintColor isEqual:[UIColor clearColor]]) {
        CGContextSetFillColorWithColor(ctx, [tintColor colorWithAlphaComponent:0.25].CGColor);
        CGContextSetBlendMode(ctx, kCGBlendModePlusLighter);
        CGContextFillRect(ctx, CGRectMake(0, 0, buffer1.width, buffer1.height));
    }

    // Create image from context
    imageRef = CGBitmapContextCreateImage(ctx);
    UIImage *image = [UIImage imageWithCGImage:imageRef scale:self.scale orientation:self.imageOrientation];
    CGImageRelease(imageRef);
    CGContextRelease(ctx);
    free(buffer1.data);

    return image;
}

- (BOOL)isARGB8888:(CGImageRef)imageRef {
    return (CGImageGetBitsPerPixel(imageRef) == 32
            && CGImageGetBitsPerComponent(imageRef) == 8
            && (CGImageGetBitmapInfo(imageRef) & kCGBitmapAlphaInfoMask));
}

- (CGContextRef)createARGBBitmapContextFromImage:(CGImageRef)inImage {
    // Get image width, height. We'll use the entire image.
    size_t pixelsWide = CGImageGetWidth(inImage);
    size_t pixelsHigh = CGImageGetHeight(inImage);
    // Declare the number of bytes per row. Each pixel in the bitmap in this
    // example is represented by 4 bytes; 8 bits each of red, green, blue, and alpha.
    int bitmapBytesPerRow = (pixelsWide * 4);
    int bitmapByteCount = (bitmapBytesPerRow * pixelsHigh);
    // Use the generic RGB color space.
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    if (colorSpace == NULL) {
        NSLog(@"Error allocating color space");
        return NULL;
    }
    // Allocate memory for image data. This is the destination in memory
    // where any drawing to the bitmap context will be rendered.
    void *bitmapData = malloc(bitmapByteCount);
    if (bitmapData == NULL) {
        NSLog(@"Memory not allocated!");
        CGColorSpaceRelease(colorSpace);
        return NULL;
    }
    // Create the bitmap context. We want pre-multiplied ARGB, 8-bits
    // per component. Regardless of what the source image format is
    // (CMYK, Grayscale, and so on) it will be converted over to the format
    // specified here by CGBitmapContextCreate.
    CGContextRef context = CGBitmapContextCreate(bitmapData,
                                     pixelsWide,
                                     pixelsHigh,
                                     8,      // bits per component
                                     bitmapBytesPerRow,
                                     colorSpace,
                                     (CGBitmapInfo) kCGImageAlphaPremultipliedFirst);
    if (context == NULL) {
        free(bitmapData);
        NSLog(@"Context not created!");
    }
    // Make sure and release colorspace before returning
    CGColorSpaceRelease(colorSpace);
    return context;
}

@end

[Vienta]

@gresrun Thx! Saved me time.