Expose libvips recombination matrix operation #1477

src/operations.cc

@@ -278,6 +278,25 @@ namespace sharp {
     return image.conv(kernel);
   }
 
+  /*
+   * Recomb with a Matrix of the given bands/channel size.
+   * Eg. RGB will be a 3x3 matrix.
+   */
+  VImage Recomb(VImage image, std::unique_ptr<double[]> const &matrix) {
+    double *m = matrix.get();
+    return image
+      .colourspace(VIPS_INTERPRETATION_sRGB)
+      .recomb(image.bands() == 3
+        ? VImage::new_from_memory(
+          m, 9 * sizeof(double), 3, 3, 1, VIPS_FORMAT_DOUBLE
+        )
+        : VImage::new_matrixv(4, 4,
+          m[0], m[1], m[2], 0.0,
+          m[3], m[4], m[5], 0.0,
+          m[6], m[7], m[8], 0.0,
+          0.0, 0.0, 0.0, 1.0));
+  }
+
   /*
    * Sharpen flat and jagged areas. Use sigma of -1.0 for fast sharpen.
    */