Demo
HarbethDemo地址
iDay每日分享文档地址
实操代码
// 用于图像阀值素描,形成有噪点的素描 let filter = C7ThresholdSketch.init(edgeStrength: 2.5, threshold: 0.25) // 方案1: let dest = BoxxIO.init(element: originImage, filter: filter) ImageView.image = try? dest.output() dest.filters.forEach { NSLog("%@", "\($0.parameterDescription)") } // 方案2: ImageView.image = try? originImage.make(filter: filter) // 方案3: ImageView.image = originImage ->> filter
实现原理
过滤器
这款滤镜采用并行计算编码器设计.compute(kernel: "C7ThresholdSketch")
,参数因子[edgeStrength, threshold]
对外开放参数
threshold
: 任何高于这个阈值的边缘都是黑色的,低于白色的任何东西都是黑色的。
edgeStrength
: 调整滤波器的动态范围。更高的值会导致更强的边缘,但可以饱和强度的色彩空间。
public struct C7ThresholdSketch: C7FilterProtocol { public static let range: ParameterRange<Float, Self> = .init(min: 0.0, max: 1.0, value: 0.25) /// Any edge above this threshold will be black, and anything below white. Ranges from 0.0 to 1.0 @ZeroOneRange public var threshold: Float = range.value /// Adjusts the dynamic range of the filter. /// Higher values lead to stronger edges, but can saturate the intensity colorspace. public var edgeStrength: Float = 1 public var modifier: Modifier { return .compute(kernel: "C7ThresholdSketch") } public var factors: [Float] { return [edgeStrength, threshold] } public init(edgeStrength: Float = 1, threshold: Float = range.value) { self.edgeStrength = edgeStrength self.threshold = threshold } }
着色器
取出周边1像素对应点的归一化坐标,获取到这些点对应的红色值;
水平方向取顶部和底部红色值做个整合处理,竖直方向取左边和右边做个整合处理,分别得到(h, v);
length
计算出范围值,step
计算出阈值对应的颜色,最后得到黑色或白色像素颜色即可;
kernel void C7ThresholdSketch(texture2d<half, access::write> outputTexture [[texture(0)]], texture2d<half, access::sample> inputTexture [[texture(1)]], constant float *edgeStrength [[buffer(0)]], constant float *threshold [[buffer(1)]], uint2 grid [[thread_position_in_grid]]) { constexpr sampler quadSampler(mag_filter::linear, min_filter::linear); const float x = float(grid.x); const float y = float(grid.y); const float width = float(inputTexture.get_width()); const float height = float(inputTexture.get_height()); const float2 leftCoordinate = float2((x - 1) / width, y / height); const float2 rightCoordinate = float2((x + 1) / width, y / height); const float2 topCoordinate = float2(x / width, (y - 1) / height); const float2 bottomCoordinate = float2(x / width, (y + 1) / height); const float2 topLeftCoordinate = float2((x - 1) / width, (y - 1) / height); const float2 topRightCoordinate = float2((x + 1) / width, (y - 1) / height); const float2 bottomLeftCoordinate = float2((x - 1) / width, (y + 1) / height); const float2 bottomRightCoordinate = float2((x + 1) / width, (y + 1) / height); const half leftIntensity = inputTexture.sample(quadSampler, leftCoordinate).r; const half rightIntensity = inputTexture.sample(quadSampler, rightCoordinate).r; const half topIntensity = inputTexture.sample(quadSampler, topCoordinate).r; const half bottomIntensity = inputTexture.sample(quadSampler, bottomCoordinate).r; const half topLeftIntensity = inputTexture.sample(quadSampler, topLeftCoordinate).r; const half topRightIntensity = inputTexture.sample(quadSampler, topRightCoordinate).r; const half bottomLeftIntensity = inputTexture.sample(quadSampler, bottomLeftCoordinate).r; const half bottomRightIntensity = inputTexture.sample(quadSampler, bottomRightCoordinate).r; half h = -topLeftIntensity - 2.0h * topIntensity - topRightIntensity + bottomLeftIntensity + 2.0h * bottomIntensity + bottomRightIntensity; h = max(0.0h, h); half v = -bottomLeftIntensity - 2.0h * leftIntensity - topLeftIntensity + bottomRightIntensity + 2.0h * rightIntensity + topRightIntensity; v = max(0.0h, v); half mag = length(half2(h, v)) * half(*edgeStrength); mag = 1.0h - step(half(*threshold), mag); const half4 outColor = half4(half3(mag), 1.0h); outputTexture.write(outColor, grid); }
Harbeth功能清单
支持ios系统和macOS系统
支持运算符函数式操作
支持多种模式数据源 UIImage, CIImage, CGImage, CMSampleBuffer, CVPixelBuffer.
支持快速设计滤镜
支持合并多种滤镜效果
支持输出源的快速扩展
支持相机采集特效
支持视频添加滤镜特效
支持矩阵卷积
支持使用系统 MetalPerformanceShaders.
支持兼容 CoreImage.
滤镜部分大致分为以下几个模块:
Blend:图像融合技术
Blur:模糊效果
Pixel:图像的基本像素颜色处理
Effect:效果处理
Lookup:查找表过滤器
Matrix: 矩阵卷积滤波器
Shape:图像形状大小相关
Visual: 视觉动态特效
MPS: 系统 MetalPerformanceShaders.
最后
慢慢再补充其他相关滤镜,喜欢就给我点个星🌟吧。
滤镜Demo地址,目前包含100+
种滤镜,同时也支持CoreImage混合使用。
再附上一个开发加速库KJCategoriesDemo地址
再附上一个网络基础库RxNetworksDemo地址
喜欢的老板们可以点个星🌟,谢谢各位老板!!!✌️.