[翻译] CoreImage-with-EAGLContext

CoreImage-with-EAGLContext

https://github.com/anaglik/CoreImage-with-EAGLContext

Simple example of drawing manipulated image to CIContext based on EAGLContext. This setup is recomended when applicaion needs Real-Time performance.(image is never copied to CPU memory).

一个简单的例子，在EAGLContext上下文中将被操作的图片绘制进CIContext。当你的应用需要实时变换图片的时候，建议你这么使用（图片永远不会被拷贝进内存当中）。

In this example I am using "CIMaskToAlpha" filter to replace background color of image below with color of main view.

这个例子中，我使用了CIMaskToAlpah滤镜，将下面图片的背景颜色替换成主view上背景颜色。

Result Image looks like this :

结果如下所示：

附录：

“UIImage+Blur.h” + “UIImage+Blur.m”

//
//  UIImage+Blur.h
//
//  Created by Luke on 13-9-3.
//  Copyright (c) 2013年 LukeCheng. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIImage (Blur)

- (UIImage *)blur:(CGFloat)radius;

- (UIImage *)blur;

@end

//
//  UIImage+Blur.m
//  
//  Created by Luke on 13-9-3.
//  Copyright (c) 2013年 LukeCheng. All rights reserved.
//

#import "UIImage+Blur.h"

@implementation UIImage (Blur)

- (UIImage *)blur:(CGFloat)radius
{
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [[CIImage alloc] initWithImage:self];
    // create gaussian blur filter
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputImage forKey:kCIInputImageKey];
    [filter setValue:[NSNumber numberWithFloat:radius] forKey:@"inputRadius"];
    // blur image
    CIImage *result = [filter valueForKey:kCIOutputImageKey];
    CGImageRef cgImage = [context createCGImage:result fromRect:[result extent]];
    UIImage *image = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);
    
    return image;
}

- (UIImage *)blur
{
    return [self blur:10.0f];
}

@end

• 
  Core Image Filters:http://developer.apple.com/library/mac/#documentation/graphicsimaging/reference/CoreImageFilterReference/Reference/reference.html
• Simple Image Processing: http://code.google.com/p/simple-iphone-image-processing/
• GLImageProcessing:http://developer.apple.com/library/ios/#samplecode/GLImageProcessing/Introduction/Intro.html
• CImg: http://cimg.sourceforge.net/reference/group__cimg__tutorial.html