1.将彩***片变为灰***片的方法:
-(UIImage *)grayImage:(UIImage *)sourceImage { int bitmapInfo = kCGImageAlphaNone; int width = sourceImage.size.width; int height = sourceImage.size.height; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray(); CGContextRef context = CGBitmapContextCreate(nil, width, height, 8, 0, colorSpace, bitmapInfo); CGColorSpaceRelease(colorSpace); if (context == NULL) { return nil; } CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage); UIImage *grayImage = [UIImage p_w_picpathWithCGImage:CGBitmapContextCreateImage(context)]; CGContextRelease(context); return grayImage; }