//

//  CIFilterEffect.h

//  CIFilter

//

//  Created by YouXianMing on 14-5-9.

//  Copyright (c) 2014年 Y.X. All rights reserved.

//

#import <Foundation/Foundation.h>

/*

CILinearToSRGBToneCurve

CIPhotoEffectChrome

CIPhotoEffectFade

CIPhotoEffectInstant

CIPhotoEffectMono

CIPhotoEffectNoir

CIPhotoEffectProcess

CIPhotoEffectTonal

CIPhotoEffectTransfer

CISRGBToneCurveToLinear

CIVignetteEffect

*/

@interface CIFilterEffect : NSObject

@property (nonatomic, strong, readonly) UIImage *filterImage;

- (instancetype)initWithImage:(UIImage *)image filterName:(NSString *)name;

@property (nonatomic, strong, readonly) UIImage *QRCodeImage;

- (instancetype)initWithQRCodeString:(NSString *)string width:(CGFloat)width;

@end

//

//  CIFilterEffect.m

//  CIFilter

//

//  Created by YouXianMing on 14-5-9.

//  Copyright (c) 2014年 Y.X. All rights reserved.

//

#import "CIFilterEffect.h"

@interface CIFilterEffect ()

@property (nonatomic, strong, readwrite) UIImage *filterImage;

@property (nonatomic, strong, readwrite) UIImage *QRCodeImage;

@end

@implementation CIFilterEffect

- (instancetype)initWithImage:(UIImage *)image filterName:(NSString *)name

{

    self = [super init];

    if (self)

    {

        // 将UIImage转换成CIImage

        CIImage *ciImage = [[CIImage alloc] initWithImage:image];

        // 创建滤镜

        CIFilter *filter = [CIFilter filterWithName:name

                                      keysAndValues:kCIInputImageKey, ciImage, nil];

        [filter setDefaults];

        // 获取绘制上下文

        CIContext *context = [CIContext contextWithOptions:nil];

        // 渲染并输出CIImage

        CIImage *outputImage = [filter outputImage];

        // 创建CGImage句柄

        CGImageRef cgImage = [context createCGImage:outputImage

                                           fromRect:[outputImage extent]];

        _filterImage = [UIImage imageWithCGImage:cgImage];

        // 释放CGImage句柄

        CGImageRelease(cgImage);

    }

    return self;

}

- (instancetype)initWithQRCodeString:(NSString *)string width:(CGFloat)width

{

    self = [super init];

    if (self)

    {

        CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

        [filter setDefaults];

        NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];

        [filter setValue:data

                  forKey:@"inputMessage"];

        CIImage *outputImage = [filter outputImage];

        CIContext *context = [CIContext contextWithOptions:nil];

        CGImageRef cgImage = [context createCGImage:outputImage

                                           fromRect:[outputImage extent]];

        UIImage *image = [UIImage imageWithCGImage:cgImage

                                             scale:0.1

                                       orientation:UIImageOrientationUp];

        // 不失真的放大

        UIImage *resized = [self resizeImage:image

                                 withQuality:kCGInterpolationNone

                                        rate:5.0];

        // 缩放到固定的宽度(高度与宽度一致)

        _QRCodeImage = [self scaleWithFixedWidth:width image:resized];

        CGImageRelease(cgImage);

    }

    return self;

}

- (UIImage *)scaleWithFixedWidth:(CGFloat)width image:(UIImage *)image

{

    float newHeight = image.size.height * (width / image.size.width);

    CGSize size = CGSizeMake(width, newHeight);

    UIGraphicsBeginImageContextWithOptions(size, NO, );

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextTranslateCTM(context, 0.0, size.height);

    CGContextScaleCTM(context, 1.0, -1.0);

    CGContextSetBlendMode(context, kCGBlendModeCopy);

    CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, size.width, size.height), image.CGImage);

    UIImage *imageOut = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return imageOut;

}

- (UIImage *)resizeImage:(UIImage *)image

             withQuality:(CGInterpolationQuality)quality

                    rate:(CGFloat)rate

{

    UIImage *resized = nil;

    CGFloat width = image.size.width * rate;

    CGFloat height = image.size.height * rate;

    UIGraphicsBeginImageContext(CGSizeMake(width, height));

    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetInterpolationQuality(context, quality);

    [image drawInRect:CGRectMake(, , width, height)];

    resized = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return resized;

}

@end