iOS GPUImage的介绍与GPUImagePicture（1）

GPUImage介绍GPUImage是一个基于GPU图像和视频处理的开源iOS框架， 提供各种各样的图像处理滤镜，并且支持照相机和摄像机的实时滤镜；使用GPUImage处理图片比Core Image更简单，只需要将过滤器赋给图片对象即可，不用考虑context或者设备等其他问题。 但目前在iOS上能用的就只有高斯模糊，而GPUImage可用的有FastBlur, GaussianBlur, GaussianSelectiveBlur 和 BoxBlur。此外，作为开源框架的GPUImage还支持自定义的过滤器。测试环境：GPUImage版本 0.1.7，Xcode 7.3，iOS 9.3项目地址：https://github.com/BradLarson/GPUImage推荐使用CocoaPods

GPUImagePicture 处理单张静态图片，类似于用美图秀秀打开一张手机照片进行P图示例：为图片添加褐色滤镜，并保存代码：////  ViewController.m//  GPUImageDemo////  Created by 黄健 on 16/6/30.//  Copyright © 2016年 hj. All rights reserved.//#import "ViewController.h"#import "GPUImage.h"@interface ViewController (){    UIImage *_inputImage;    UIImage *_outputImage;}@property (weak, nonatomic) IBOutlet UIImageView *iconImageView;@property (nonatomic,strong) GPUImageOutput<GPUImageInput>   *filter;@property (nonatomic,strong) GPUImageView                    *filterImageView;@property (nonatomic,strong) GPUImagePicture *stillImageSource;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // 图片输入源    _inputImage = [UIImage imageNamed:@"icon"];    // 初始化图片     self.stillImageSource = [[GPUImagePicture alloc] initWithImage:_inputImage];    // 初始化滤镜     self.filter = [[GPUImageSepiaFilter alloc] init];    // 向图片添加滤镜    [self.stillImageSource addTarget:_filter];    // 开始处理图片    [self.filter useNextFrameForImageCapture];    [self.stillImageSource processImage];    // 输出处理后的图片    _outputImage = [_filter imageFromCurrentFramebuffer];    // 显示处理后的图片    self.iconImageView.image = _outputImage;}- (IBAction)saveToAblum:(id)sender{    // 保存图片到本地    UIImageWriteToSavedPhotosAlbum(_outputImage, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);}- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{    if (error == nil) {        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"已存入手机相册" delegate:self cancelButtonTitle:nil otherButtonTitles:@"确定", nil];        [alert show];    }else{        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"保存失败" delegate:self cancelButtonTitle:nil otherButtonTitles:@"确定", nil];        [alert show];    }}- (IBAction)showInputImage:(id)sender{    // 显示原图    self.iconImageView.image = _inputImage;}- (IBAction)showOutImage:(id)sender{    // 显示新图    self.iconImageView.image = _outputImage;}- (IBAction)saveToTemp:(id)sender{    // 保存图片到沙盒    NSString *sandBoxPath = NSHomeDirectory();    NSString *saveImagePath = [sandBoxPath stringByAppendingString:@"/Documents/helloworld.png"];    [UIImagePNGRepresentation(_outputImage) writeToFile:saveImagePath atomically:YES];#if 0    //Document目录    NSArray *dirArray1    = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *documentDir = [documentDir objectAtIndex:0];    //Library目录    NSArray *dirArray3    = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);    NSString *libraryDir  = [libraryDir objectAtIndex:0];    //Caches目录    NSArray *dirArray3    = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);    NSString *cachesDir   = [cacheDir objectAtIndex:0];#endif}@end测试：