Factor out boolean[][] -> BitMatrix parsing

core/src/main/java/com/google/zxing/common/BitMatrix.java

@@ -40,11 +40,21 @@ public final class BitMatrix implements Cloneable {
   private final int rowSize;
   private final int[] bits;
 
-  // A helper to construct a square matrix.
+  /**
+   * Creates an empty square {@link BitMatrix}.
+   *
+   * @param dimension height and width
+   */
   public BitMatrix(int dimension) {
     this(dimension, dimension);
   }
 
+  /**
+   * Creates an empty {@link BitMatrix}.
+   *
+   * @param width bit matrix width
+   * @param height bit matrix height
+   */
   public BitMatrix(int width, int height) {
     if (width < 1 || height < 1) {
       throw new IllegalArgumentException("Both dimensions must be greater than 0");
@@ -62,6 +72,27 @@ public final class BitMatrix implements Cloneable {
     this.bits = bits;
   }
 
+  /**
+   * Interprets a 2D array of booleans as a {@link BitMatrix}, where "true" means an "on" bit.
+   *
+   * @param image bits of the image, as a row-major 2D array. Elements are arrays representing rows
+   * @return {@link BitMatrix} representation of image
+   */
+  public static BitMatrix parse(boolean[][] image) {
+    int height = image.length;
+    int width = image[0].length;
+    BitMatrix bits = new BitMatrix(width, height);
+    for (int i = 0; i < height; i++) {
+      boolean[] imageI = image[i];
+      for (int j = 0; j < width; j++) {
+        if (imageI[j]) {
+          bits.set(j, i);
+        }
+      }
+    }
+    return bits;
+  }
+
   public static BitMatrix parse(String stringRepresentation, String setString, String unsetString) {
     if (stringRepresentation == null) {
       throw new IllegalArgumentException();

core/src/main/java/com/google/zxing/datamatrix/decoder/Decoder.java

@@ -48,17 +48,7 @@ public final class Decoder {
    * @throws ChecksumException if error correction fails
    */
   public DecoderResult decode(boolean[][] image) throws FormatException, ChecksumException {
-    int dimension = image.length;
-    BitMatrix bits = new BitMatrix(dimension);
-    for (int i = 0; i < dimension; i++) {
-      boolean[] imageI = image[i];
-      for (int j = 0; j < dimension; j++) {
-        if (imageI[j]) {
-          bits.set(j, i);
-        }
-      }
-    }
-    return decode(bits);
+    return decode(BitMatrix.parse(image));
   }
 
   /**

core/src/main/java/com/google/zxing/qrcode/decoder/Decoder.java

@@ -57,17 +57,7 @@ public final class Decoder {
    */
   public DecoderResult decode(boolean[][] image, Map<DecodeHintType,?> hints)
       throws ChecksumException, FormatException {
-    int dimension = image.length;
-    BitMatrix bits = new BitMatrix(dimension);
-    for (int i = 0; i < dimension; i++) {
-      boolean[] imageI = image[i];
-      for (int j = 0; j < dimension; j++) {
-        if (imageI[j]) {
-          bits.set(j, i);
-        }
-      }
-    }
-    return decode(bits, hints);
+    return decode(BitMatrix.parse(image), hints);
   }
 
   public DecoderResult decode(BitMatrix bits) throws ChecksumException, FormatException {