Class MedianBlurOp

java.lang.Object
cloud.opencode.base.image.filter.MedianBlurOp
public final class MedianBlurOp extends Object
Median Blur Filter 中值模糊滤波器

Applies median filtering to images using the Huang sliding histogram algorithm, achieving O(W*H*K) time complexity instead of the naive O(W*H*K^2).

使用 Huang 滑动直方图算法对图像进行中值滤波， 时间复杂度为 O(W*H*K)，优于朴素算法的 O(W*H*K^2)。

Features | 主要功能:

  • Effective salt-and-pepper noise removal - 有效去除椒盐噪声
  • Edge-preserving smoothing - 保边平滑
  • Huang sliding histogram for efficient computation - Huang 滑动直方图高效计算
  • Independent R/G/B channel processing with alpha preservation - 独立 R/G/B 通道处理，Alpha 通道保持不变

Usage Examples | 使用示例:

// Remove salt-and-pepper noise with 3x3 median filter
Raster filtered = MedianBlurOp.apply(noisyRaster, 3);

// Stronger filtering with 5x5 kernel
Raster filtered = MedianBlurOp.apply(noisyRaster, 5);

Performance | 性能特性:

  • Time: O(W * H * K) via Huang sliding histogram - 时间: O(W * H * K) 通过 Huang 滑动直方图
  • Space: O(W * H) + O(256) histogram - 空间: O(W * H) + O(256) 直方图

Security | 安全性:

  • Thread-safe: Yes (stateless) - 线程安全: 是（无状态）
Since:
JDK 25, opencode-base-image V2.0.0
Author:
Leon Soo www.LeonSoo.com
See Also:

  • Method Details

    • apply

      public static Raster apply(Raster raster, int kernelSize)
      Apply median filter to a Raster. 对 Raster 应用中值滤波。
      Parameters:
      raster - the source raster | 源 raster
      kernelSize - the kernel size (must be odd and >= 3) | 核大小（奇数且 >= 3）
      Returns:
      the filtered raster | 滤波后的 raster
      Throws:
      ImageOperationException - if raster is null or kernelSize is invalid | 参数无效时抛出
      Since:
      opencode-base-image V1.0.4

    • apply

      public static Raster apply(Raster raster, int kernelSize, Raster dst)
      Apply median filter to a Raster with optional caller-provided output buffer. Output format is RGBA_8 when the source has alpha, otherwise RGB_8. 对 Raster 应用中值滤波，可指定输出缓冲。 源含 alpha 时输出 RGBA_8，否则 RGB_8。
      Parameters:
      raster - the source raster | 源 raster
      kernelSize - the kernel size (must be odd and >= 3) | 核大小（奇数且 >= 3）
      dst - optional output raster, may be null | 可选输出 raster，可为 null
      Returns:
      the filtered raster | 滤波后的 raster
      Throws:
      ImageOperationException - if raster is null or kernelSize is invalid | 参数无效时抛出
      Since:
      opencode-base-image V1.0.4