我想模糊矩形或圆形图像。谷歌搜索后，我发现很容易模糊整个图像，但很难模糊图像的特定部分（矩形、圆形）。那怎么可能？？？
提前致谢
【问题讨论】：
标签： iphone objective-c ios
只需将您的UIImageView 属性名称设置为“imageView”，并在您的实现文件中以相同的顺序添加以下四个方法。
此外，将您的 ImageView 模式设置为“重绘”。为给定的模糊效果添加 UIImage 类别或使用任何自定义类，它将为您工作。
方法 1 - 裁剪图像
#pragma mark - Cropping the Image
- (UIImage *)croppIngimageByImageName:(UIImage *)imageToCrop toRect:(CGRect)rect{
CGImageRef imageRef = CGImageCreateWithImageInRect([imageToCrop CGImage], rect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return cropped;
}
方法2 - 合并两个图像
#pragma mark - Marge two Images
- (UIImage *) addImageToImage:(UIImage *)img withImage2:(UIImage *)img2 andRect:(CGRect)cropRect{
CGSize size = CGSizeMake(imageView.image.size.width, imageView.image.size.height);
UIGraphicsBeginImageContext(size);
CGPoint pointImg1 = CGPointMake(0,0);
[img drawAtPoint:pointImg1];
CGPoint pointImg2 = cropRect.origin;
[img2 drawAtPoint: pointImg2];
UIImage* result = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return result;
}
方法 3 - RoundRect 图像
#pragma mark - RoundRect the Image
- (UIImage *)roundedRectImageFromImage:(UIImage *)image withRadious:(CGFloat)radious {
if(radious == 0.0f)
return image;
if( image != nil) {
CGFloat imageWidth = image.size.width;
CGFloat imageHeight = image.size.height;
CGRect rect = CGRectMake(0.0f, 0.0f, imageWidth, imageHeight);
UIWindow *window = [[[UIApplication sharedApplication] windows] objectAtIndex:0];
const CGFloat scale = window.screen.scale;
UIGraphicsBeginImageContextWithOptions(rect.size, NO, scale);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextBeginPath(context);
CGContextSaveGState(context);
CGContextTranslateCTM (context, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGContextScaleCTM (context, radious, radious);
CGFloat rectWidth = CGRectGetWidth (rect)/radious;
CGFloat rectHeight = CGRectGetHeight (rect)/radious;
CGContextMoveToPoint(context, rectWidth, rectHeight/2.0f);
CGContextAddArcToPoint(context, rectWidth, rectHeight, rectWidth/2.0f, rectHeight, radious);
CGContextAddArcToPoint(context, 0.0f, rectHeight, 0.0f, rectHeight/2.0f, radious);
CGContextAddArcToPoint(context, 0.0f, 0.0f, rectWidth/2.0f, 0.0f, radious);
CGContextAddArcToPoint(context, rectWidth, 0.0f, rectWidth, rectHeight/2.0f, radious);
CGContextRestoreGState(context);
CGContextClosePath(context);
CGContextClip(context);
[image drawInRect:CGRectMake(0.0f, 0.0f, imageWidth, imageHeight)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
return nil;
}
方法 4 - 触摸移动
#pragma mark - Touch Methods
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UIImage *croppedImg = nil;
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.imageView];
double ratioW=imageView.image.size.width/imageView.frame.size.width ;
double ratioH=imageView.image.size.height/imageView.frame.size.height;
currentPoint.x *= ratioW;
currentPoint.y *= ratioH;
double circleSizeW = 30 * ratioW;
double circleSizeH = 30 * ratioH;
currentPoint.x = (currentPoint.x - circleSizeW/2<0)? 0 : currentPoint.x - circleSizeW/2;
currentPoint.y = (currentPoint.y - circleSizeH/2<0)? 0 : currentPoint.y - circleSizeH/2;
CGRect cropRect = CGRectMake(currentPoint.x , currentPoint.y, circleSizeW, circleSizeH);
NSLog(@"x %0.0f, y %0.0f, width %0.0f, height %0.0f", cropRect.origin.x, cropRect.origin.y, cropRect.size.width, cropRect.size.height );
croppedImg = [self croppIngimageByImageName:self.imageView.image toRect:cropRect];
// Blur Effect
croppedImg = [croppedImg imageWithGaussianBlur9];
// Contrast Effect
// croppedImg = [croppedImg imageWithContrast:50];
croppedImg = [self roundedRectImageFromImage:croppedImg withRadious:4];
imageView.image = [self addImageToImage:imageView.image withImage2:croppedImg andRect:cropRect];
}
UIImage 类别类
UIImage+ImageBlur.h
#import <UIKit/UIKit.h>
@interface UIImage (ImageBlur)
- (UIImage *)imageWithGaussianBlur9;
@end
UIImage+ImageBlur.m
#import "UIImage+ImageBlur.h"
@implementation UIImage (ImageBlur)
- (UIImage *)imageWithGaussianBlur9 {
float weight[5] = {0.1270270270, 0.1945945946, 0.1216216216, 0.0540540541, 0.0162162162};
// Blur horizontally
UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
[self drawInRect:CGRectMake(0, 0, self.size.width, self.size.height) blendMode:kCGBlendModeNormal alpha:weight[0]];
for (int x = 1; x < 5; ++x) {
[self drawInRect:CGRectMake(x, 0, self.size.width, self.size.height) blendMode:kCGBlendModeNormal alpha:weight[x]];
[self drawInRect:CGRectMake(-x, 0, self.size.width, self.size.height) blendMode:kCGBlendModeNormal alpha:weight[x]];
}
UIImage *horizBlurredImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// Blur vertically
UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
[horizBlurredImage drawInRect:CGRectMake(0, 0, self.size.width, self.size.height) blendMode:kCGBlendModeNormal alpha:weight[0]];
for (int y = 1; y < 5; ++y) {
[horizBlurredImage drawInRect:CGRectMake(0, y, self.size.width, self.size.height) blendMode:kCGBlendModeNormal alpha:weight[y]];
[horizBlurredImage drawInRect:CGRectMake(0, -y, self.size.width, self.size.height) blendMode:kCGBlendModeNormal alpha:weight[y]];
}
UIImage *blurredImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//
return blurredImage;
}
@end
愉快的编码......
【讨论】：
在 view 或 imageview 中添加以下 Pangesture
UIPanGestureRecognizer *panGesture=[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(imageTaped:)];
[panGesture setMaximumNumberOfTouches:1];
[self.view addGestureRecognizer:panGesture];
模糊图像的方法
- (void)imageTaped:(UIPanGestureRecognizer *)gestureRecognizer
{
CIContext *context = [CIContext contextWithOptions:nil];
CGPoint touchLocation = [gestureRecognizer locationInView:self.imgviewMain];
CGRect temp=CGRectMake(touchLocation.x-25, ((self.imgviewMain.frame.size.height-50) - touchLocation.y)+25, 50, 50);
CIImage *inputImage0 = [[CIImage alloc] initWithImage:self.imgviewMain.image];
CIImage *inputImage = [[CIImage alloc] initWithImage:[UIImage imageWithCGImage:[context createCGImage:inputImage0 fromRect:temp]]];
CIFilter *blurFilter = [CIFilter filterWithName:@"CIGaussianBlur"];
[blurFilter setDefaults];
[blurFilter setValue: inputImage forKey: @"inputImage"];
[blurFilter setValue: [NSNumber numberWithFloat:0.1]
forKey:@"inputRadius"];
CIImage *outputImage = [blurFilter valueForKey: @"outputImage"];
UIImageView *imgtest=[[UIImageView alloc]init];
imgtest.image=[UIImage imageWithCGImage:[context createCGImage:outputImage fromRect:outputImage.extent]];
UIImage *image;
UIImage *bottomImage = self.imgviewMain.image;
image = imgtest.image;
CGSize newSize = CGSizeMake(self.imgviewMain.frame.size.width, self.imgviewMain.frame.size.height);
UIGraphicsBeginImageContext( newSize );
[bottomImage drawInRect:CGRectMake(0,0,768,1024)];
CGRect newRect2=CGRectMake(temp.origin.x,((self.imgviewMain.frame.size.height-50) - temp.origin.y), image.size.width, image.size.height);
image=[self makeRoundedImage:image radius:10];
[image drawInRect:newRect2 blendMode:kCGBlendModeNormal alpha:0.5];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
self.imgviewMain.image=newImage;
}
圆形图像方法
-(UIImage *)makeRoundedImage:(UIImage *) image
radius: (float) radius;
{
CALayer *imageLayer = [CALayer layer];
imageLayer.frame = CGRectMake(0, 0, image.size.width, image.size.height);
imageLayer.contents = (id) image.CGImage;
imageLayer.masksToBounds = YES;
imageLayer.cornerRadius = radius;
UIGraphicsBeginImageContext(image.size);
[imageLayer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *roundedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return roundedImage;
}
【讨论】：
我知道我参加聚会有点晚了，但它可能会帮助其他努力完成这项工作的人。
我最近需要实现它，但我在互联网上找不到关于这个特定主题的太多信息（特别是在处理不同的 UIImageView 的比例类型时如何让它工作，如 Scale to Fill、Center 等） .所以我开发了一个小项目，完全符合您的期望。
【讨论】：
我设法为基于 OSX 的项目进行了 insta blur。 OSX 和 iOS 的绘图和图形上下文管理代码可能不同。 希望这可以帮助其他想做类似事情的 macOS 开发者！
在这里，当用户拖动鼠标时，我们裁剪图像并将其覆盖在主图像视图上
- (void)mouseDragged:(NSEvent *)theEvent {
NSPoint currentPoint = [self.view convertPoint:[theEvent locationInWindow] fromView:nil];
NSPoint currentPointForOverLay = currentPoint;
double ratioW=self.imageView.image.size.width/ self.imageView.frame.size.width ;
double ratioH=self.imageView.image.size.height/self.imageView.frame.size.height;
double circleSizeW = 30; //Width and Height of Rect
double circleSizeH = 30;
currentPointBackup.x *= ratioW;
currentPointBackup.y *= ratioH;
CGRect overLayRect = CGRectMake(currentPointBackup.x , currentPointBackup.y, circleSizeW * ratioW, circleSizeH * ratioH);
CGRect cropRect = CGRectMake(currentPoint.x, currentPoint.y, circleSizeW, circleSizeH);
//NSLog(@"x %0.0f, y %0.0f, width %0.0f, height %0.0f", cropRect.origin.x, cropRect.origin.y, cropRect.size.width, cropRect.size.height);
//Logic to CROP Image on OSX
NSSize ratio = [(NSImageView*)self.imageExtractor.canvasController.contentView originalImageRatio];
CGFloat x = cropRect.origin.x / ratio.width;
CGFloat y = cropRect.origin.y / ratio.height;
CGFloat w = cropRect.size.width / ratio.width;
CGFloat h = cropRect.size.height / ratio.height;
NSRect sourceFrame = NSMakeRect(x, y, w, h);
NSRect targetFrame = NSMakeRect(0, 0, w*1.0f, h*1.0f);
NSImage *targetImage = [[NSImage alloc] initWithSize:targetFrame.size];
if(targetImage.size.width > 0 && targetFrame.size.height > 0) {
[targetImage lockFocus];
[[(NSImageView*)self.imageExtractor.canvasController.contentView originalImage] drawInRect:targetFrame fromRect:sourceFrame operation:NSCompositingOperationCopy fraction:1.0f];
[targetImage unlockFocus];
}
//End CROP Image on OSX
//Apply filters
NSData *data = targetImage.TIFFRepresentation;
CIImage *croppedCIImage = [[CIImage alloc] initWithData:data];
CIImage *filteredCIImage;
if (self.filterTypeOnCanvas == BlurFilterMode)
{
CGFloat filterValue = self.blurSlider.floatValue;
filteredCIImage = [filterManager getBlurredImage:croppedCIImage withAmount:filterValue];
}
else if (self.filterTypeOnCanvas == PixilateFilterMode)
{
CGFloat filterValue = self.pixillateSlider.floatValue;
filteredCIImage = [filterManager getPixellatedImage:croppedCIImage withAmount:filterValue];
}
CGImageRef cgimgRef = [context createCGImage:filteredCIImage
fromRect:[croppedCIImage extent]];
NSImage *blurredNSImage = [[NSImage alloc] initWithCGImage:cgimgRef size:cropRect.size];
//Finally overlay the blurred image on main image
NSImage *newImage = [imageUtils overlayImages:self.imageView.image overlayImage:blurredNSImage overLayRect:nsRect];
self.imageView.image = newImage;
}
叠加图像逻辑
- (NSImage *) overlayImages:(NSImage *)backgroundImage overlayImage:(NSImage *)overlayImage
overLayRect:(NSRect)overLayRect
{
NSImage *newImage = [[NSImage alloc] initWithSize:[backgroundImage size]];
[newImage lockFocus];
CGRect newImageRect = CGRectZero;
newImageRect.size = [newImage size];
[backgroundImage drawInRect:newImageRect];
[overlayImage drawInRect:overLayRect];
[newImage unlockFocus];
return newImage;
}
应用过滤器
-(CIImage *)getBlurredImage:(CIImage *)img withAmount:(float)intensity {
CIFilter *blurFilter = [CIFilter filterWithName:@"CIDiscBlur"];
[blurFilter setValue:img forKey:kCIInputImageKey];
[blurFilter setValue:@(intensity) forKey:@"inputRadius"];
return blurFilter.outputImage;
}
-(CIImage *)getPixellatedImage:(CIImage *)img withAmount:(float)scale
{
CIFilter *pixilateFilter = [CIFilter filterWithName:@"CIPixellate"];
[pixilateFilter setValue:img forKey:kCIInputImageKey];
[pixilateFilter setValue:@(scale) forKey:@"inputScale"];
return pixilateFilter.outputImage;
}
【讨论】：