代码地址如下：
http://www.demodashi.com/demo/14277.html
演示效果
演示效果
代码结构
项目结构截图如下：
该模块的核心源码部分为 MBPartBlurView，要放到自己的工程中，直接把该目录copy进去。剩余部分是测试用的。
使用介绍
使用方法
头文件 MBPartBlurView.h 中的注释很详细，使用起来也很简单，目前支持三种形式的图形，圆形、正方形和长方形。
@interface MBPartBlurView : UIView
/**
* 原始图片
*/
@property (nonatomic, strong) UIImage *rawImage;
/**
* 处理完的图片
*/
@property (nonatomic, strong, readonly) UIImage *currentImage;
@property (nonatomic, assign) CGFloat blurRadius;
/**
* 不进行blur的区域
*/
@property (nonatomic, assign) CGRect excludeBlurArea;
/**
* 不进行blur的区域是否是圆形 (目前只支持正方形)
*/
@property (nonatomic, assign) BOOL excludeAreaCircle;
@end程序实现
局部模糊的实现
局部模糊实际上是两张图片叠加在一起的效果，底部是一张全部模糊的图片，顶部是一张未经过模糊的图片。对顶部图片加上mask，然后贴在底部图上。
a. 底部的图片放在 imageView 的 layer 上。顶部图片放在 rawImageLayer 上。
maskLayer 就是遮罩层，作为 rawImageLayer 的遮罩。他们分别由以下三个属性保持
@property (nonatomic, strong) UIImageView *imageView;
@property (nonatomic, strong) CALayer *rawImageLayer;
@property (nonatomic, strong) CAShapeLayer *maskLayer;b. 初始化的过程。图层一目了然
- (void)commonInit
{
[self.imageView addGestureRecognizer:self.tapGesture];
[self.imageView addGestureRecognizer:self.pinchGesture];
[self.brushView addGestureRecognizer:self.panGesture];
[self addSubview:self.imageView];
[self.imageView.layer addSublayer:self.rawImageLayer];
[self.imageView addSubview:self.brushView];
self.rawImageLayer.mask = self.maskLayer;
[self setExcludeAreaCircle:true];
[self setExcludeBlurArea:CGRectMake(100, 100, 100, 100)];
[self showBrush:false];
}1. 图片模糊算法
算法用的是业界广泛使用的高斯模糊。
(UIImage *)blurryImage:(UIImage *)image withBlurLevel:(CGFloat)blur
{
NSData *imageData = UIImageJPEGRepresentation(image, 1); // convert to jpeg
UIImage* destImage = [UIImage imageWithData:imageData];
int boxSize = (int)(blur * 100);
if (blur > 0.5) {
boxSize = (int)(blur * 100) + 50;
}else if (blur <= 0.5) {
boxSize = (int)(blur * 100);
}
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;
}2.手势处理
主要是实现缩放的手势，在处理 UIPanGestureRecognizer 的函数- (void)handlePinch:(UIPinchGestureRecognizer *)gestureRecognizer 中，当 state 为 UIGestureRecognizerStateChanged 时候调用核心缩放函数- (void)scaleMask:(CGFloat)scale，代码具体如下：
- (void)scaleMask:(CGFloat)scale
{
CGFloat mS = MIN(self.imageView.frame.size.width/self.brushView.frame.size.width, self.imageView.frame.size.height/self.brushView.frame.size.height);
CGFloat s = MIN(scale, mS);
[CATransaction setDisableActions:YES];
CGAffineTransform zoomTransform = CGAffineTransformScale(self.brushView.layer.affineTransform, s, s);
self.brushView.layer.affineTransform = zoomTransform;
zoomTransform = CGAffineTransformScale(self.maskLayer.affineTransform, s, s);
self.maskLayer.affineTransform = zoomTransform;
[CATransaction setDisableActions:false];
}在这个函数中，更新maskLayer 的 affineTransform 就可以扩大或者缩小 mask 的范围。表现出来就是不模糊的区域扩大或者缩小。
3. 处理相机图片自动旋转问题
- (void)setRawImage:(UIImage *)rawImage
{
UIImage *newImage = [self fixedOrientation:rawImage]; //从相册出来的自带90度旋转
_rawImage = newImage;
CGFloat w,h;
if (newImage.size.width >= newImage.size.height) {
w = self.frame.size.width;
h = newImage.size.height/newImage.size.width * w;
}
else {
h = self.frame.size.height;
w = newImage.size.width/newImage.size.height * h;
}
self.imageView.frame = CGRectMake(0.5 *(self.frame.size.width-w), 0.5 *(self.frame.size.height-h), w, h);
self.rawImageLayer.frame = self.imageView.bounds;
self.imageView.image = [self blurryImage:newImage withBlurLevel:self.blurRadius];
self.rawImageLayer.contents = (id)newImage.CGImage;
}补充
暂时没有
[1]: http://www.ruanyifeng.com/blog/2012/11/gaussian_blur.htmliOS 图片部分模糊，类似于美图秀秀
代码地址如下：
http://www.demodashi.com/demo/14277.html
注：本文著作权归作者，由demo大师代发，拒绝转载，转载需要作者授权