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最新推荐文章于 2025-09-07 01:02:55 发布

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最新推荐文章于 2025-09-07 01:02:55 发布

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文章标签： python

原文链接：https://my.oschina.net/u/2519763/blog/863750

本文介绍了一种在iOS应用中实现图片模糊效果的方法。通过使用vImageBoxConvolve_ARGB8888函数进行盒状模糊处理，该方法能够有效地为图片添加模糊效果。文章详细展示了如何从CGImage中获取像素数据并进行模糊处理的过程。

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[_headerImageView sd_setImageWithURL:[NSURL URLWithString:imageUrl] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
           _headerImageView.image = [self boxblurImage:_headerImageView.image withBlurNumber:0.2];
    }];

-(UIImage *)boxblurImage:(UIImage *)image withBlurNumber:(CGFloat)blur
{
    if (!image) {
        image = IMAGENAMED(@"default_icon");
    }
    if (blur < 0.f || blur > 1.f) {
        blur = 0.2f;
    }
    int boxSize = (int)(blur * 40);
    boxSize = boxSize - (boxSize % 2) + 1;
    CGImageRef img = image.CGImage;
    vImage_Buffer inBuffer, outBuffer;
    vImage_Error error;
    void *pixelBuffer;
    //从CGImage中获取数据
    CGDataProviderRef inProvider = CGImageGetDataProvider(img);
    CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
    //设置从CGImage获取对象的属性
    inBuffer.width = CGImageGetWidth(img);
    inBuffer.height = CGImageGetHeight(img);
    inBuffer.rowBytes = CGImageGetBytesPerRow(img);
    inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
    pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
    if(pixelBuffer == NULL)
        NSLog(@"No pixelbuffer");
    outBuffer.data = pixelBuffer;
    outBuffer.width = CGImageGetWidth(img);
    outBuffer.height = CGImageGetHeight(img);
    outBuffer.rowBytes = CGImageGetBytesPerRow(img);
    error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
    if (error) {
        NSLog(@"error from convolution %ld", error);
    }
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef ctx = CGBitmapContextCreate( outBuffer.data, outBuffer.width, outBuffer.height, 8, outBuffer.rowBytes, colorSpace, kCGImageAlphaNoneSkipLast);
    CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
    UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
    //clean up CGContextRelease(ctx);
    CGColorSpaceRelease(colorSpace);
    free(pixelBuffer);
    CFRelease(inBitmapData);
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(imageRef);
    return returnImage;
}

转载于:https://my.oschina.net/u/2519763/blog/863750