GPUImageGaussianBlurFilter似乎不适用于分层过滤器

Question

我有分层滤波器，所有看上去都很好的图像，我正在使用，但如果我改变高斯模糊参数，要么更高，要么更低，没有明显的差异，在模糊效果。我做错什么了？

这是我的代码：

GPUImageView *finalView;

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIImage *topLayer = [UIImage imageNamed:@"Glass.png"];
    UIImage *baseLayer = [UIImage imageNamed:@"BasePhoto.png"];

    GPUImagePicture *stillImageSourceTop = [[GPUImagePicture alloc] initWithImage:topLayer];
    GPUImagePicture *stillImageSourceBottom = [[GPUImagePicture alloc] initWithImage:baseLayer];

    GPUImageScreenBlendFilter *screenBlendFilter = [[GPUImageScreenBlendFilter alloc] init];
    GPUImageBrightnessFilter *brightnessFilter = [[GPUImageBrightnessFilter alloc] init];
    GPUImageContrastFilter *contrastFilter = [[GPUImageContrastFilter alloc] init];
    GPUImageSaturationFilter *saturationFilter = [[GPUImageSaturationFilter alloc] init];
    GPUImageColorMatrixFilter *colorMatrixFilter = [[GPUImageColorMatrixFilter alloc] init];
    GPUImageOpacityFilter *opacityFilter = [[GPUImageOpacityFilter alloc] init];
    opacityFilter.opacity = 0;

    GPUImageGaussianBlurFilter *blurFilter = [[GPUImageGaussianBlurFilter alloc]init];
    blurFilter.texelSpacingMultiplier = 4.0;
    blurFilter.blurRadiusInPixels = 200.0;
    blurFilter.blurPasses = 4;


    [stillImageSourceTop addTarget:brightnessFilter];
    [brightnessFilter addTarget:contrastFilter];
    [contrastFilter addTarget:saturationFilter];
    [saturationFilter addTarget:colorMatrixFilter];
    [colorMatrixFilter addTarget:blurFilter];
    [blurFilter addTarget:opacityFilter];

    [stillImageSourceTop processImage]; 
    [opacityFilter useNextFrameForImageCapture];

    UIImage *topLayerImage = [opacityFilter imageFromCurrentFramebuffer];
    GPUImagePicture *stillImageSourceTopWithFilters = [[GPUImagePicture alloc] initWithImage:topLayerImage];

    [stillImageSourceBottom addTarget:screenBlendFilter];
    [stillImageSourceTopWithFilters addTarget:screenBlendFilter];
    [screenBlendFilter useNextFrameForImageCapture];

    [stillImageSourceBottom processImage];

    UIImage *mergedlayeredimage = [screenBlendFilter imageFromCurrentFramebuffer];
   [finalImageView setImage:mergedlayeredimage];

}

Answer 1

嗯，这是因为上面提到的大多数过滤器实际上什么都不做。您所连接的唯一过滤器是screenBlendFilter，在这里，您可以将源图像放入其中，然后从其中提取一个图像。你从来没有实际使用模糊在那里的任何东西，所以它当然不会影响输出任何。