IOS图片的两种处理：加阴影和变灰色

#import <QuartzCore/QuartzCore.h>

//图片阴影

UIImageView *img;

[[img layer] setShadowOffset:CGSizeMake(5, 5)];

[[img layer] setShadowRadius:6];

[[img layer] setShadowOpacity:1];

[[img layer] setShadowColor:[UIColor lightGrayColor].CGColor];

//变灰色

-(UIImage*)getGrayImage:(UIImage*)sourceImage

{

int width = sourceImage.size.width;

int height = sourceImage.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), sourceImage.CGImage);

UIImage *grayImage = [UIImage imageWithCGImage:CGBitmapContextCreateImage(context)];

CGContextRelease(context);

return grayImage;

}