iOS CoreImage图片处理动态渲染(滤镜)

//

//  ViewController.m

//  CoreImageOfDong

//

//  Created by Dong on 15/6/30.

//  Copyright (c) 2015年 xindong. All rights reserved.

//

#import "ViewController.h"

#import <GLKit/GLKit.h>
// 须要导入此库

@interface ViewController ()

@property (nonatomic,
strong)
GLKView *glkView;
//渲染用的buffer视图(类似流媒体,实时改变)

@property (nonatomic, strong) CIFilter *filter;

@property (nonatomic, strong) CIImage *ciImage;

@property (nonatomic, strong) CIContext *ciContext;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

UIImage *showImage = [UIImage imageNamed:@"demo1.jpg"];

CGRect rect = CGRectMake(0, 0, showImage.size.width, showImage.size.height);

// 获取OpenGLES渲染的上下文

EAGLContext *eagContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];

// 创建出渲染的buffer

self.glkView = [[GLKView alloc] initWithFrame:rect context:eagContext];

[self.glkView bindDrawable];
// 绑定绘制,否则刚開始会黑屏

[self.view addSubview:self.glkView];

// 创建出CoreImage用的上下文

self.ciContext = [CIContext contextWithEAGLContext:eagContext options:@{kCIContextWorkingColorSpace : [NSNull null]}];

// CoreImage相关设置

self.ciImage = [[CIImage alloc] initWithImage:showImage];

self.filter = [CIFilter filterWithName:@"CISepiaTone"];

[self.filter setValue:self.ciImage forKey:kCIInputImageKey];

[self.filter setValue:@(0) forKey:kCIInputIntensityKey];

// 開始渲染

[self.ciContext drawImage:[self.filter valueForKey:kCIOutputImageKey] inRect:CGRectMake(0, 0, self.glkView.drawableWidth, self.glkView.drawableHeight) fromRect:[self.ciImage
extent]];

[self.glkView display];

//
动态渲染

UISlider *slider = [[UISlider alloc] initWithFrame:CGRectMake(30, 500, 200, 10)];

slider.minimumValue = 0.f;

slider.maximumValue = 10.f;

[slider addTarget:self action:@selector(changeColorValue:) forControlEvents:UIControlEventValueChanged];

[self.view addSubview:slider];

}

- (void)changeColorValue:(UISlider *)slider

{

[self.filter setValue:self.ciImage forKey:kCIInputImageKey];

[self.filter setValue:@(slider.value) forKey:kCIInputIntensityKey];

// 開始渲染

[self.ciContext drawImage:[self.filter valueForKey:kCIOutputImageKey] inRect:CGRectMake(0, 0, self.glkView.drawableWidth, self.glkView.drawableHeight) fromRect:[self.ciImage
extent]];

[self.glkView display];

}