iOS开发--毛玻璃效果（UIImage+Blur）直接拿去

最新推荐文章于 2024-08-28 10:00:29 发布

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#ios #界面 #uiimage

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本文介绍如何利用Objective-C实现UIImage的模糊效果，包括导入必要的头文件，定义扩展方法，通过调整模糊参数来生成毛玻璃效果的图片实例，并提供实际的使用示例。

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这里写图片描述

代码：

#import <UIKit/UIKit.h>
#import <Accelerate/Accelerate.h>
@interface UIImage (Blur)
-(UIImage *)imageWithBlur:(CGFloat)blur;
@end

#import "UIImage+Blur.h"

@implementation UIImage (Blur)

#pragma mark --毛玻璃效果
-(UIImage *)imageWithBlur:(CGFloat)blur {

    NSData *imageData = UIImageJPEGRepresentation(self, 1); // convert to jpeg
    UIImage* destImage = [UIImage imageWithData:imageData];


    if (blur < 0.f || blur > 1.f) {
        blur = 0.5f;
    }
    int boxSize = (int)(blur * 40);
    boxSize = boxSize - (boxSize % 2) + 1;

    CGImageRef img = destImage.CGImage;

    vImage_Buffer inBuffer, outBuffer;

    vImage_Error error;

    void *pixelBuffer;


    //create vImage_Buffer with data from CGImageRef

    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);

    //create vImage_Buffer for output

    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);

    // Create a third buffer for intermediate processing
    void *pixelBuffer2 = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
    vImage_Buffer outBuffer2;
    outBuffer2.data = pixelBuffer2;
    outBuffer2.width = CGImageGetWidth(img);
    outBuffer2.height = CGImageGetHeight(img);
    outBuffer2.rowBytes = CGImageGetBytesPerRow(img);

    //perform convolution
    error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer2, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
    if (error) {
        NSLog(@"error from convolution %ld", error);
    }
    error = vImageBoxConvolve_ARGB8888(&outBuffer2, &inBuffer, NULL, 0, 0, boxSize, boxSize, NULL, kvImageEdgeExtend);
    if (error) {
        NSLog(@"error from convolution %ld", error);
    }
    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,
                                             (CGBitmapInfo)kCGImageAlphaNoneSkipLast);
    CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
    UIImage *returnImage = [UIImage imageWithCGImage:imageRef];

    //clean up
    CGContextRelease(ctx);
    CGColorSpaceRelease(colorSpace);

    free(pixelBuffer);
    free(pixelBuffer2);
    CFRelease(inBitmapData);

    CGImageRelease(imageRef);

    return returnImage;
}
@end

用法：

    UIImageView *imageView = [[UIImageView alloc]initWithFrame:[[UIScreen mainScreen]bounds]];
    [self.view addSubview:imageView];
     UIImage *image = [UIImage imageNamed:@"332a4a1eff7b50757eb8126948ab1ef6.jpg"];
    imageView.image = [image boxblurImageWithBlur:1];