Xcode - 多个照片过滤器

Question

我正在创建一个包含滤镜的照片应用。过滤器可以工作，但它们会保持永久性并相互重叠。例如，我希望从图像中删除棕褐色滤镜，并在按下即时滤镜按钮时替换为即时滤镜。我如何实现这一目标？以下是该项目的一些代码：

- (IBAction)sepiaFilter:(id)sender {

    CIImage *beginImage = [CIImage imageWithData: UIImagePNGRepresentation(self.picture.image)];
    CIContext *context = [CIContext contextWithOptions:nil];
    CIFilter *filter = [CIFilter filterWithName:@"CISepiaTone" keysAndValues:kCIInputImageKey, beginImage, @"inputIntensity", [NSNumber numberWithFloat:0.8], nil ];
    CIImage *outputImage = [filter outputImage];
    CGImageRef cging = [context createCGImage:outputImage fromRect:[outputImage extent]];
    self.picture.image = [UIImage imageWithCGImage:cging];
    CGImageRelease(cging);     
}

- (IBAction)instantFilter:(id)sender {

    CIImage *beginImage = [CIImage imageWithData: UIImagePNGRepresentation(self.picture.image)];
    CIContext *context = [CIContext contextWithOptions:nil];
    CIFilter *filterTwo = [CIFilter filterWithName:@"CIPhotoEffectInstant" keysAndValues:kCIInputImageKey, beginImage, nil ];
    CIImage *outputImage = [filterTwo outputImage];
    CGImageRef cging = [context createCGImage:outputImage fromRect:[outputImage extent]];
    self.picture.image = [UIImage imageWithCGImage:cging];
    CGImageRelease(cging);
}

（我实际上有九个过滤器，但我只需要知道如何做到这一点）感谢您的帮助

Answer 1

这很简单。您正在使用self.picture.image 进行输入和输出。将原始的UIImage 单独保留用于输入，并将self.picture.image 仅用于输出，因此您的代码中唯一更改的是两个过滤器的第一行，即

CIImage *beginImage = [CIImage imageWithData: UIImagePNGRepresentation(self.originalImage)];

希望这会有所帮助。