ios - GPUImage 平均颜色与应用的灰度过滤器不匹配

Question

我在使用 GPUImage 时遇到以下问题:1st 我在相机上添加了一个灰度滤镜，然后我使用 GPUImageAverageColor 来获得平均颜色。问题是我通过 block 获得的颜色不在灰度范围内。我做错了什么？

这是代码:

    GPUImageVideoCamera *videoCamera = [[GPUImageVideoCamera alloc] initWithSessionPreset:AVCaptureSessionPreset640x480 cameraPosition:AVCaptureDevicePositionBack];
    videoCamera.outputImageOrientation = UIInterfaceOrientationPortrait;

    GPUImageView *filterView = (GPUImageView *)self.cameraLayer;
    [filterView setFillMode:kGPUImageFillModePreserveAspectRatioAndFill];

    GPUImageGrayscaleFilter *grayscaleFilter = [[GPUImageGrayscaleFilter alloc] init];
    [videoCamera addTarget:grayscaleFilter];
    [grayscaleFilter addTarget:filterView];

    GPUImageAverageColor *averageColor = [[GPUImageAverageColor alloc] init];
    [averageColor setColorAverageProcessingFinishedBlock:^(CGFloat redComponent, CGFloat greenComponent, CGFloat blueComponent, CGFloat alphaComponent, CMTime frameTime){

        NSLog(@"Red: %f, green: %f, blue: %f, alpha: %f", redComponent, greenComponent, blueComponent, alphaComponent);

    }];

    [videoCamera addTarget:averageColor];
    [videoCamera startCameraCapture];

Answer 1

那是因为您实际上并未对灰度输出运行平均颜色操作。

查看您如何定位过滤器。您将摄像机的输出直接发送到您的平均色彩操作。您需要改为将灰度过滤器的输出发送到平均颜色操作。