iOS 图片编辑——滤镜

iOS中涉及图片编辑中最常见的一种就是滤镜 如下图

有关图片缩放剪切功能参见：http://blog.csdn.net/lwjok2007/article/details/50845510

首先 ，我们打开Xcode 新建项目 

起名：testImageFilterProcess1

拖入几个必要代码（见demo。demo下载地址见QQ群空间：414319235）

拖入过程弹出的选择框选择如下

接下来，我们在默认生成的ViewController中写代码

创建一个变量 用来显示图片

    UIImageView * imageView;

创建两个button 分别用来拍照 和处理照片

- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.    UIButton *btn=[[UIButton alloc]initWithFrame:CGRectMake(50, 50, 100, 50)];    [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];    [btn setTitle:@"拍照" forState:UIControlStateNormal];    [btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn];            UIButton *btn1=[[UIButton alloc]initWithFrame:CGRectMake(self.view.bounds.size.width-150, 50, 100, 50)];    [btn1 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];    [btn1 setTitle:@"滤镜" forState:UIControlStateNormal];    [btn1 addTarget:self action:@selector(btn1Click) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:btn1];        imageView=[[UIImageView alloc]initWithFrame:CGRectMake(10, 120, self.view.bounds.size.width-20, self.view.bounds.size.height-130)];    imageView.image=[UIImage imageNamed:@"320-480.png"];    [self.view addSubview:imageView];        }

最终界面如下

实现拍照按钮点击事件

-(void)btnClick{        UIActionSheet *actionSheet;    actionSheet = [[UIActionSheet alloc]initWithTitle:@"请选择" delegate:self cancelButtonTitle:@"取消" destructiveButtonTitle:nil otherButtonTitles:@"照相机",@"相册", nil];    actionSheet.delegate=self;    [actionSheet showInView:self.view];}

-(void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex{        if (buttonIndex==0) {        UIImagePickerController *imagePicker=[[UIImagePickerController alloc]init];        imagePicker.allowsEditing=YES;        imagePicker.sourceType=UIImagePickerControllerSourceTypeCamera;        imagePicker.delegate=self;        [self presentViewController:imagePicker animated:false completion:nil];    }else if (buttonIndex==1){        UIImagePickerController *imagePicker=[[UIImagePickerController alloc]init];        imagePicker.allowsEditing=YES;        imagePicker.sourceType=UIImagePickerControllerSourceTypePhotoLibrary;        imagePicker.delegate=self;        [self presentViewController:imagePicker animated:false completion:nil];    }}

imagePickerController 代理方法

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{    [picker dismissViewControllerAnimated:true completion:nil];    UIImage *image;    image=[info valueForKey:UIImagePickerControllerOriginalImage];    image=[self clipImageWithScaleWithsize:CGSizeMake(320, 480) image:image];        imageView.image=image;}

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{        [picker dismissViewControllerAnimated:true completion:nil];    NSLog(@"pickerpickerpicker=%@",picker);}

去掉图片之后要用如下方法处理一下 否则会因为内存过大而崩掉

- (UIImage *)clipImageWithScaleWithsize:(CGSize)asize image:(UIImage *) image{    UIImage *newimage;    if (nil == image) {        newimage = nil;    }    else{        CGSize oldsize = image.size;        CGRect rect;        if (asize.width/asize.height > oldsize.width/oldsize.height) {            rect.size.width = asize.width;            rect.size.height = asize.width*oldsize.height/oldsize.width;            rect.origin.x = 0;            rect.origin.y = (asize.height - rect.size.height)/2;        }        else{            rect.size.width = asize.height*oldsize.width/oldsize.height;            rect.size.height = asize.height;            rect.origin.x = (asize.width - rect.size.width)/2;            rect.origin.y = 0;        }        UIGraphicsBeginImageContext(asize);        CGContextRef context = UIGraphicsGetCurrentContext();        CGContextClipToRect(context, CGRectMake(0, 0, asize.width, asize.height));        CGContextSetFillColorWithColor(context, [[UIColor clearColor] CGColor]);        UIRectFill(CGRectMake(0, 0, asize.width, asize.height));//clear background        [image drawInRect:rect];        newimage = UIGraphicsGetImageFromCurrentImageContext();        UIGraphicsEndImageContext();    }    return newimage;}

接下来 实现滤镜按钮点击的事件

-(void)btn1Click{        ImageFilterProcessViewController *fitler = [[ImageFilterProcessViewController alloc] init];    [fitler setDelegate:self];    fitler.currentImage = imageView.image;    [self presentModalViewController:fitler animated:YES];    }

实现一下滤镜的代理方法 获取修改完成的图片

- (void)imageFitlerProcessDone:(UIImage *)image //图片处理完{    imageView.image=image;}

好了 到此基本完成 运行试试

源代码将上传到群空间 有兴趣的下载看看

demo：【60311图片滤镜ImageFilterProcess1.zip】
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