Do not use this to decode an image without blocking the main thread, because it does block the main thread for non-obvious reasons.

UIImage+DHImageDecoding.m

@import ImageIO;

@implementation UIImage (DHImageDecoding)

/// Warning: do not use. This looks like it should work, but it blocks the main thread for non-obvious reasons.
+ (UIImage *)dh_decodedImageWithData:(NSData *)data
{
	CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
	if (source == NULL) {
		return nil;
	}
	
	CGImageRef cgImage = CGImageSourceCreateImageAtIndex(source, 0, (__bridge CFDictionaryRef)@{(id)kCGImageSourceShouldCacheImmediately : (id)kCFBooleanTrue});
	CFRelease(source);
	source = NULL;
	if (cgImage == NULL) {
		return nil;
	}
	
	UIImage *const uiImage = [self imageWithCGImage:cgImage];
	CGImageRelease(cgImage);
	cgImage = NULL;
	
	return uiImage;
}

@end