GPUImageGaussianBlurFilter似乎不适用于分层滤镜

Question

我有分层的滤镜，这些滤镜在我使用的图像上看起来都很棒，但是如果我将Gaussian Blur参数更改为较高或较低，则模糊效果没有明显的区别。 我究竟做错了什么 ？

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，那是因为上面的大多数过滤器实际上没有执行任何操作。 连接的唯一过滤器是screenBlendFilter，将源图像都放入其中，然后从中拉出一个图像。 您实际上从来不会对那里的任何东西使用模糊，因此，它当然不会影响输出。