Fix complex morphology

src/main/java/domain/image/processing/morphology/ComplexMorphology.java

@@ -37,9 +37,11 @@ public class ComplexMorphology {
 
         while (true) {
             Mat dilated = new Mat();
+
             Imgproc.dilate(current, dilated, kernel);
 
             Mat next = new Mat();
+
             Core.min(dilated, maskMat, next);
 
             double difference = Core.norm(next, current, Core.NORM_INF);
@@ -53,7 +55,13 @@ public class ComplexMorphology {
     }
 
     public static GrayScaleMatrix medianFilter(Image image, int tailleMasque) {
-        Mat input = toMat(image);
+        if (tailleMasque < 1 || tailleMasque % 2 == 0) {
+            throw new IllegalArgumentException(
+                    "Median filter size must be a positive odd number"
+            );
+        }
+
+        Mat input = to8BitMat(image);
         Mat result = new Mat();
 
         Imgproc.medianBlur(input, result, tailleMasque);
@@ -61,6 +69,10 @@ public class ComplexMorphology {
         return toGrayScaleMatrix(result);
     }
 
+    /**
+     * Converts an image to a CV_64F grayscale matrix.
+     * Used by geodesic morphology operations.
+     */
     private static Mat toMat(Image image) {
         GrayScaleMatrix gray = image.toGrayScale();
 
@@ -78,8 +90,39 @@ public class ComplexMorphology {
         return mat;
     }
 
+    /**
+     * Converts an image to an 8-bit grayscale matrix.
+     * Required by OpenCV medianBlur().
+     */
+    private static Mat to8BitMat(Image image) {
+        GrayScaleMatrix gray = image.toGrayScale();
+
+        int width = gray.getWidth();
+        int height = gray.getHeight();
+
+        Mat mat = new Mat(height, width, CvType.CV_8UC1);
+
+        double[][] data = gray.getRawData();
+
+        for (int y = 0; y < height; y++) {
+            byte[] row = new byte[width];
+
+            for (int x = 0; x < width; x++) {
+                int value = (int) Math.round(data[y][x]);
+                value = Math.clamp(value, 0, 255);
+
+                row[x] = (byte) value;
+            }
+
+            mat.put(y, 0, row);
+        }
+
+        return mat;
+    }
+
     private static Mat createKernel(int size) {
-        return Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(size, size));
+        return Imgproc.getStructuringElement( Imgproc.MORPH_RECT, new Size(size, size)
+        );
     }
 
     private static GrayScaleMatrix toGrayScaleMatrix(Mat mat) {
@@ -88,11 +131,22 @@ public class ComplexMorphology {
 
         double[][] output = new double[height][width];
 
+        if (mat.type() == CvType.CV_8UC1) {
+            for (int y = 0; y < height; y++) {
+                byte[] row = new byte[width];
+                mat.get(y, 0, row);
+
+                for (int x = 0; x < width; x++) {
+                    output[y][x] = Byte.toUnsignedInt(row[x]);
+                }
+            }
+        } else {
             for (int y = 0; y < height; y++) {
                 for (int x = 0; x < width; x++) {
                     output[y][x] = mat.get(y, x)[0];
                 }
             }
+        }
 
         return new GrayScaleMatrix(output);
     }