Question

我正在尝试在Apples原生相机中模仿人像模式。

问题是，使用CIImage对深度数据应用模糊效果对于我想向用户显示的实时预览来说太慢了。

我的代码就是：

func blur(image: CIImage, mask: CIImage, orientation: UIImageOrientation = .up, blurRadius: CGFloat) -> UIImage? {
    let start = Date()
    let invertedMask = mask.applyingFilter("CIColorInvert")

    let output = image.applyingFilter("CIMaskedVariableBlur", withInputParameters: ["inputMask" : invertedMask,
                                                                                    "inputRadius": blurRadius])

    guard let cgImage = context.createCGImage(output, from: image.extent) else {
        return nil
    }
    let end = Date()
    let elapsed = end.timeIntervalSince1970 - start.timeIntervalSince1970
    print("took \(elapsed) seconds to apply blur")
    return UIImage(cgImage: cgImage, scale: 1.0, orientation: orientation)
}

我想在GPU上应用模糊以获得更好的性能。对于此任务，我发现Apple here

提供了此实现

所以在Apple的实现中，我们有这段代码：

/** Applies a Gaussian blur with a sigma value of 0.5.
 This is a pre-packaged convolution filter.
 */
class GaussianBlur: CommandBufferEncodable {
    let gaussian: MPSImageGaussianBlur

    required init(device: MTLDevice) {
        gaussian = MPSImageGaussianBlur(device: device,
                                    sigma: 5.0)
    }

    func encode(to commandBuffer: MTLCommandBuffer, sourceTexture: MTLTexture, destinationTexture: MTLTexture) {
        gaussian.encode(commandBuffer: commandBuffer,
                    sourceTexture: sourceTexture,
                    destinationTexture: destinationTexture)
    }
}

我的问题：如何通过Metal blur版本将深度数据应用到过滤中？或者换句话说 - 如何利用第二个代码片段的性能速度实现第一个代码片段功能？

将MPSImageGaussianBlur应用于深度数据

0 个答案: