前言：在iOS项目开发中，有很多时候我们需要将某张图片进行一些处理，以达到某些特定效果。在这里我们将提供图片的三种效果以供大家借鉴，如果各位大神有更多的效果，也请不吝赐教。
方法调用
// 二值化
- (IBAction)coverToGrayScale:(id)sender {
_imageView.image = [_imageView.image covertToGrayScale];
}
// 高斯模糊
- (IBAction)gaosiBlur:(id)sender {
_imageView.image = [_imageView.image gaussianBlur];
}
// 灰度
- (IBAction)grayImage:(id)sender {
_imageView.image = [_imageView.image grayImage];
}
/** 二值化 */
- (UIImage *)covertToGrayScale{
CGSize size =[self size];
int width =size.width;
int height =size.height;
//像素将画在这个数组
uint32_t *pixels = (uint32_t *)malloc(width *height *sizeof(uint32_t));
//清空像素数组
memset(pixels, 0, width*height*sizeof(uint32_t));
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
//用 pixels 创建一个 context
CGContextRef context =CGBitmapContextCreate(pixels, width, height, 8, width*sizeof(uint32_t), colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedLast);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), [self CGImage]);
int tt =1; CGFloat intensity; int bw; for (int y = 0; y 0.45?255:0; rgbaPixel[tt] = bw; rgbaPixel[tt + 1] = bw; rgbaPixel[tt + 2] = bw;
} }
CGImageRef image = CGBitmapContextCreateImage(context); CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
free(pixels);
UIImage *resultUIImage = [UIImage imageWithCGImage:image]; CGImageRelease(image);
return resultUIImage; }
/** 转化灰度 */
- (UIImage *)grayImage{
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; }
#pragma mark - 高斯模糊
- (UIImage *)gaussianBlur; {
//转换图片
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *midImage = [CIImage imageWithData:UIImagePNGRepresentation(self)];
//图片开始处理
CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
[filter setValue:midImage forKey:kCIInputImageKey];
//value 改变模糊效果值
[filter setValue:@10.0f forKey:@"inputRadius"];
CIImage *result =[filter valueForKey:kCIOutputImageKey];
CGImageRef outImage =[context createCGImage:result fromRect:[result extent]];
//转化为 UIImage
UIImage *resultImage =[UIImage imageWithCGImage:outImage]; CGImageRelease(outImage);
return resultImage;
}
#pragma mark - 滤镜处理
- (UIImage *)setFilterWithFilterName:(NSString *)filterName {
//转换图片
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *midImage = [CIImage imageWithData:UIImagePNGRepresentation(self)];
//图片开始处理
CIFilter *filter = [CIFilter filterWithName:filterName];
@try {
[filter setValue:midImage forKey:kCIInputImageKey];
}
@catch (NSException *exception) {
} @finally {
}
CIImage *result =[filter valueForKey:kCIOutputImageKey];
CGImageRef outImage =[context createCGImage:result fromRect:[result extent]];
//转化为 UIImage
UIImage *resultImage =[UIImage imageWithCGImage:outImage]; CGImageRelease(outImage);
return resultImage; }