Enhancement: add support to recomb for 4x4 recombination matrices

lovell · Jul 2, 2024 · c66b118 · c66b118
1 parent eab7dc1
commit c66b118
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Showing 12 changed files with 80 additions and 30 deletions.
diff --git a/lib/constructor.js b/lib/constructor.js
@@ -346,6 +346,8 @@ const Sharp = function (input, options) {
     timeoutSeconds: 0,
     linearA: [],
     linearB: [],
+    recombMatrixSize: 3,
+
     // Function to notify of libvips warnings
     debuglog: warning => {
       this.emit('warning', warning);

diff --git a/lib/index.d.ts b/lib/index.d.ts
@@ -571,11 +571,11 @@ declare namespace sharp {
 
         /**
          * Recomb the image with the specified matrix.
-         * @param inputMatrix 3x3 Recombination matrix
+         * @param inputMatrix 3x3 Recombination matrix or 4x4 Recombination matrix
          * @throws {Error} Invalid parameters
          * @returns A sharp instance that can be used to chain operations
          */
-        recomb(inputMatrix: Matrix3x3): Sharp;
+        recomb(inputMatrix: Matrix3x3 | Matrix4x4): Sharp;
 
         /**
          * Transforms the image using brightness, saturation, hue rotation and lightness.
@@ -1730,6 +1730,7 @@ declare namespace sharp {
 
     type Matrix2x2 = [[number, number], [number, number]];
     type Matrix3x3 = [[number, number, number], [number, number, number], [number, number, number]];
+    type Matrix4x4 = [[number, number, number, number], [number, number, number, number], [number, number, number, number], [number, number, number, number]];
 }
 
 export = sharp;
diff --git a/lib/operation.js b/lib/operation.js
@@ -787,24 +787,28 @@ function linear (a, b) {
  *     // With this example input, a sepia filter has been applied
  *   });
  *
- * @param {Array<Array<number>>} inputMatrix - 3x3 Recombination matrix
+ * @param {Array<Array<number>>} inputMatrix - 3x3 Recombination matrix or 4x4 Recombination matrix
  * @returns {Sharp}
  * @throws {Error} Invalid parameters
  */
 function recomb (inputMatrix) {
-  if (!Array.isArray(inputMatrix) || inputMatrix.length !== 3 ||
-      inputMatrix[0].length !== 3 ||
-      inputMatrix[1].length !== 3 ||
-      inputMatrix[2].length !== 3
-  ) {
-    // must pass in a kernel
+  if (!Array.isArray(inputMatrix)) {
+    throw new Error('Invalid recombination matrix');
+  }
+
+  const length = inputMatrix.length;
+  if (length !== 3 && length !== 4) {
     throw new Error('Invalid recombination matrix');
   }
-  this.options.recombMatrix = [
-    inputMatrix[0][0], inputMatrix[0][1], inputMatrix[0][2],
-    inputMatrix[1][0], inputMatrix[1][1], inputMatrix[1][2],
-    inputMatrix[2][0], inputMatrix[2][1], inputMatrix[2][2]
-  ].map(Number);
+
+  for (const row of inputMatrix) {
+    if (row.length !== length) {
+      throw new Error('Invalid recombination matrix');
+    }
+  }
+
+  this.options.recombMatrix = inputMatrix.flat().map(Number);
+  this.options.recombMatrixSize = length;
   return this;
 }
 

diff --git a/src/operations.cc b/src/operations.cc
@@ -183,19 +183,24 @@ namespace sharp {
    * 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) {
+  VImage Recomb(VImage image, std::unique_ptr<double[]> const &matrix, int recombMatrixSize) {
     double *m = matrix.get();
     image = image.colourspace(VIPS_INTERPRETATION_sRGB);
-    return image
-      .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));
+    if (recombMatrixSize == 3) {
+      return image
+        .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));
+    } else {
+      return image
+        .recomb(VImage::new_from_memory(m, 16 * sizeof(double), 4, 4, 1, VIPS_FORMAT_DOUBLE));
+    }
   }
 
   VImage Modulate(VImage image, double const brightness, double const saturation,

diff --git a/src/operations.h b/src/operations.h
@@ -95,7 +95,7 @@ namespace sharp {
    * 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);
+  VImage Recomb(VImage image, std::unique_ptr<double[]> const &matrix, int recombMatrixSize);
 
   /*
    * Modulate brightness, saturation, hue and lightness

diff --git a/src/pipeline.cc b/src/pipeline.cc
@@ -610,7 +610,7 @@ class PipelineWorker : public Napi::AsyncWorker {
 
       // Recomb
       if (baton->recombMatrix != NULL) {
-        image = sharp::Recomb(image, baton->recombMatrix);
+        image = sharp::Recomb(image, baton->recombMatrix, baton->recombMatrixSize);
       }
 
       // Modulate
@@ -1613,10 +1613,16 @@ Napi::Value pipeline(const Napi::CallbackInfo& info) {
     }
   }
   if (options.Has("recombMatrix")) {
-    baton->recombMatrix = std::unique_ptr<double[]>(new double[9]);
+    baton->recombMatrixSize = sharp::AttrAsInt32(options, "recombMatrixSize");
+    if (baton->recombMatrixSize == 3) {
+      baton->recombMatrix = std::unique_ptr<double[]>(new double[9]);
+    } else {
+      baton->recombMatrix = std::unique_ptr<double[]>(new double[16]);
+    }
     Napi::Array recombMatrix = options.Get("recombMatrix").As<Napi::Array>();
-    for (unsigned int i = 0; i < 9; i++) {
-       baton->recombMatrix[i] = sharp::AttrAsDouble(recombMatrix, i);
+    unsigned int matrixElements = baton->recombMatrixSize * baton->recombMatrixSize;
+    for (unsigned int i = 0; i < matrixElements; i++) {
+      baton->recombMatrix[i] = sharp::AttrAsDouble(recombMatrix, i);
     }
   }
   baton->colourspacePipeline = sharp::AttrAsEnum<VipsInterpretation>(

diff --git a/src/pipeline.h b/src/pipeline.h
@@ -224,6 +224,7 @@ struct PipelineBaton {
   std::string tileId;
   std::string tileBasename;
   std::unique_ptr<double[]> recombMatrix;
+  int recombMatrixSize;
 
   PipelineBaton():
     input(nullptr),

diff --git a/test/fixtures/d.png b/test/fixtures/d.png
diff --git a/test/fixtures/expected/d-opacity-30.png b/test/fixtures/expected/d-opacity-30.png
diff --git a/test/fixtures/index.js b/test/fixtures/index.js
@@ -139,6 +139,7 @@ module.exports = {
 
   testPattern: getPath('test-pattern.png'),
 
+  inputPngWithTransparent: getPath('d.png'),
   // Path for tests requiring human inspection
   path: getPath,
 

diff --git a/test/types/sharp.test-d.ts b/test/types/sharp.test-d.ts
@@ -295,6 +295,13 @@ sharp('input.gif')
     [0.2392, 0.4696, 0.0912],
   ])
 
+  .recomb([
+    [1,0,0,0],
+    [0,1,0,0],
+    [0,0,1,0],
+    [0,0,0,1],
+  ])
+
   .modulate({ brightness: 2 })
   .modulate({ hue: 180 })
   .modulate({ lightness: 10 })

diff --git a/test/unit/recomb.js b/test/unit/recomb.js
@@ -121,6 +121,29 @@ describe('Recomb', function () {
       });
   });
 
+  it('applies opacity 30% to the image', function (done) {
+    const output = fixtures.path('output.recomb-opacity.png');
+    sharp(fixtures.inputPngWithTransparent)
+      .recomb([
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [0, 0, 0, 0.3]
+      ])
+      .toFile(output, function (err, info) {
+        if (err) throw err;
+        assert.strictEqual('png', info.format);
+        assert.strictEqual(48, info.width);
+        assert.strictEqual(48, info.height);
+        fixtures.assertMaxColourDistance(
+          output,
+          fixtures.expected('d-opacity-30.png'),
+          17
+        );
+        done();
+      });
+  });
+
   describe('invalid matrix specification', function () {
     it('missing', function () {
       assert.throws(function () {