这篇文章简单介绍一些图片处理的用法
图片裁剪、高斯模糊
image
//图片裁剪、高斯模糊
//显示两个UIImageView，可以很好地对比效果
//下面这几个image方法是yykit库里边的方法
- (void)clipsImage {
imageView1 = [[UIImageView alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
UIImage *imag1 = [UIImage imageNamed:@"test"];
imageView1.image = imag1;
[self.view addSubview:imageView1];
imageView2 = [[UIImageView alloc] initWithFrame:CGRectMake(100, imageView1.bottom + 20, 200, 200)];
UIImage *image2 = [UIImage imageNamed:@"test"];
//重新设置image大小
UIImage *image3 = [image2 imageByResizeToSize:CGSizeMake(400, 400)];
//需要截取的区域
imageView2.image = [image3 imageByCropToRect:CGRectMake(0, 0, 100, 100)];
//设置Insets
// UIImage *image4 = [image2 imageByInsetEdge:UIEdgeInsetsMake(30, 30, 30, 30) withColor:[UIColor redColor]];
// imageView2.image = image4;
//设置高斯模糊
// imageView2.image = [image2 imageByBlurSoft];
[self.view addSubview:imageView2];
}
//和上面裁剪效果一样
- (void)clipsImage1 {
imageView0 = [[UIImageView alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
UIImage *imag1 = [UIImage imageNamed:@"test"];
imageView0.image = imag1;
[self.view addSubview:imageView0];
imageView1 = [[UIImageView alloc] initWithFrame:CGRectMake(100, imageView0.bottom + 20, 200, 200)];
UIImage *imag = [UIImage imageNamed:@"test"];
//重新设置将要被裁剪的image大小、设置需要裁剪的区域
imageView1.image = [UIImage cutImage:imag imageViewSize:CGSizeMake(400, 400) clipRect:CGRectMake(0, 0, 100, 100)];
[self.view addSubview:imageView1];
}
+ (UIImage *)cutImage:(UIImage *)image
imageViewSize:(CGSize)size
clipRect:(CGRect)rect {
//图片大小和实际显示大小的比例
CGFloat scale_width = image.size.width/size.width;
CGFloat scale_height = image.size.height/size.height;
//实际剪切区域
CGRect clipRect = CGRectMake(rect.origin.x * scale_width,
rect.origin.y * scale_height,
rect.size.width * scale_width,
rect.size.height * scale_height);
//开启图形上下文
UIGraphicsBeginImageContext(clipRect.size);
//画图
[image drawAtPoint:CGPointMake(-clipRect.origin.x, -clipRect.origin.y)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
scaleImage
+ (UIImage *)scaleImage:(UIImage *)image sclae:(CGFloat)scale {
//确定压缩后的size
CGFloat scaleWidth = image.size.width * scale;
CGFloat scaleHeight = image.size.height * scale;
CGSize scaleSize = CGSizeMake(scaleWidth, scaleHeight);
//开启图形上下文
UIGraphicsBeginImageContext(scaleSize);
//绘制图片
[image drawInRect:CGRectMake(0, 0, scaleWidth, scaleHeight)];
//从图形上下文获取图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
//关闭图形上下文
UIGraphicsEndImageContext();
return newImage;
}
图片上边写文字、图片贴在图片上
image
imageView1 = [[UIImageView alloc] initWithFrame:CGRectMake(100, 120, 200, 200)];
UIImage *image = [UIImage imageNamed:@"test"];
UIImage *image3 = [UIImage waterAtImage:image text:@"这个文章不错" point:imageView1.center attributes:@{NSFontAttributeName: [UIFont systemFontOfSize:36], NSForegroundColorAttributeName: [UIColor redColor]}];
UIImage *image4 = [UIImage waterAtImage:image3 waterImgae:[UIImage imageNamed:@"test-1"] rect:CGRectMake(50, 50, 100, 100)];
imageView1.image = image4;
[self.view addSubview:imageView1];
+ (UIImage *)waterAtImage:(UIImage *)image
text:(NSString *)text
point:(CGPoint)point
attributes:(NSDictionary *)attributes {
//开启图形上下文
UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);
//绘制图片
[image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
//添加文字
[text drawAtPoint:point withAttributes:attributes];
//获取图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
//关闭上下文
UIGraphicsEndImageContext();
return newImage;
}
+ (UIImage *)waterAtImage:(UIImage *)image
waterImgae:(UIImage *)waterImage
rect:(CGRect)rect {
//开启图形上下文
UIGraphicsBeginImageContextWithOptions(image.size, NO, 0);
//绘制原图片
[image drawInRect:CGRectMake(0, 0, image.size.width, image.size.width)];
//绘制水印
[waterImage drawInRect:rect];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
刮刮乐效果
刮刮乐效果其实就是两个ImageView叠加在一起，在上层imageview添加手势，然后根据手指在imageview划过的痕迹处理为透明色即可。
image
- (void)alphaImage {
imageView2 = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
imageView2.contentMode = UIViewContentModeCenter;
UIImage *imag = [UIImage createImageColor:[UIColor yellowColor] size:CGSizeMake(200, 200)];
imageView2.image = imag;
imageView1 = [[UIImageView alloc] initWithFrame:CGRectMake(100, 120, 200, 200)];
UIImage *image = [UIImage imageNamed:@"test"];
UIImage *image3 = [UIImage waterAtImage:image text:@"这个文章不错" point:imageView1.center attributes:@{NSFontAttributeName: [UIFont systemFontOfSize:36], NSForegroundColorAttributeName: [UIColor redColor]}];
UIImage *image4 = [UIImage waterAtImage:image3 waterImgae:[UIImage imageNamed:@"test-1"] rect:CGRectMake(50, 50, 100, 100)];
imageView1.image = image4;
[self.view addSubview:imageView1];
[imageView1 addSubview:imageView2];
imageView1.userInteractionEnabled = YES;
imageView2.userInteractionEnabled = YES;
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pangesture:)];
[imageView2 addGestureRecognizer:pan];
}
- (void)pangesture:(UIPanGestureRecognizer *)pan {
CGPoint point = [pan locationInView:imageView2];
UIImage *image = [UIImage wipeView:imageView2 point:point size:CGSizeMake(20, 20)];
imageView2.image = image;
}
//size 刮过的路径宽高
+ (UIImage *)wipeView:(UIView *)view
point:(CGPoint)point
size:(CGSize)size {
//开启图形上下文
UIGraphicsBeginImageContext(view.bounds.size);
//获取当前上下文
CGContextRef ctx = UIGraphicsGetCurrentContext();
//渲染
[view.layer renderInContext:ctx];
//计算擦除的rect
CGFloat clipX = point.x - size.width/2;
CGFloat clipY = point.y - size.height/2;
CGRect clipRect = CGRectMake(clipX, clipY, size.width, size.height);
//将该区域设置为透明
CGContextClearRect(ctx, clipRect);
//获取新的图片
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
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