UIImage获取灰度图像

#import <UIKit/UIKit.h>

@interface UIImage(grayImage)

-(UIImage*)getGrayImage;

@end

#import "UIImage+grayImage.h"

@implementation UIImage(grayImage)

-(UIImage*)getGrayImage{
int width =
self.size.width;
int height =
self.size.height;
CGColorSpaceRef colorSpace =
CGColorSpaceCreateDeviceGray();
CGContextRef context =
CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);
CGColorSpaceRelease(colorSpace);
if (context ==
NULL) {
return
nil;
}
CGContextDrawImage(context,CGRectMake(0,
0, width, height), self.CGImage);
UIImage *grayImage = [UIImage
imageWithCGImage:CGBitmapContextCreateImage(context)];
CGContextRelease(context);
return grayImage;
}
@end