C# port, add datamatrix code

[zxing.git] / csharp / datamatrix / DataMatrixReader.cs

diff --git a/csharp/datamatrix/DataMatrixReader.cs b/csharp/datamatrix/DataMatrixReader.cs
new file mode 100644 (file)
index 0000000..4c87612
--- /dev/null
+++ b/csharp/datamatrix/DataMatrixReader.cs
@@ -0,0 +1,118 @@
+using System;\r
+using System.Collections.Generic;\r
+using System.Linq;\r
+using com.google.zxing;\r
+using com.google.zxing.common;\r
+using com.google.zxing.datamatrix.decoder;\r
+using com.google.zxing.datamatrix.detector;\r
+\r
+namespace com.google.zxing.datamatrix\r
+{\r
+    public sealed class DataMatrixReader\r
+    {\r
+          private static  ResultPoint[] NO_POINTS = new ResultPoint[0];\r
+          private Decoder decoder = new Decoder();\r
+\r
+          /**\r
+           * Locates and decodes a Data Matrix code in an image.\r
+           *\r
+           * @return a String representing the content encoded by the Data Matrix code\r
+           * @throws ReaderException if a Data Matrix code cannot be found, or cannot be decoded\r
+           */\r
+          public Result decode(MonochromeBitmapSource image) {\r
+            return decode(image, null);\r
+          }\r
+\r
+          public Result decode(MonochromeBitmapSource image, System.Collections.Hashtable hints)\r
+              {\r
+            DecoderResult decoderResult;\r
+            ResultPoint[] points;\r
+            if (hints != null && hints.ContainsKey(DecodeHintType.PURE_BARCODE)) {\r
+              BitMatrix bits = extractPureBits(image);\r
+              decoderResult = decoder.decode(bits);\r
+              points = NO_POINTS;\r
+            } else {\r
+              DetectorResult detectorResult = new Detector(image).detect();\r
+              decoderResult = decoder.decode(detectorResult.getBits());\r
+              points = detectorResult.getPoints();\r
+            }\r
+            Result result = new Result(decoderResult.getText(), decoderResult.getRawBytes(), points, BarcodeFormat.DATAMATRIX);\r
+            if (decoderResult.getByteSegments() != null) {\r
+              result.putMetadata(ResultMetadataType.BYTE_SEGMENTS, decoderResult.getByteSegments());\r
+            }\r
+            return result;\r
+          }\r
+\r
+          /**\r
+           * This method detects a Data Matrix code in a "pure" image -- that is, pure monochrome image\r
+           * which contains only an unrotated, unskewed, image of a Data Matrix code, with some white border\r
+           * around it. This is a specialized method that works exceptionally fast in this special\r
+           * case.\r
+           */\r
+          private static BitMatrix extractPureBits(MonochromeBitmapSource image) {\r
+            // Now need to determine module size in pixels\r
+\r
+            int height = image.getHeight();\r
+            int width = image.getWidth();\r
+            int minDimension = Math.Min(height, width);\r
+\r
+            // First, skip white border by tracking diagonally from the top left down and to the right:\r
+            int borderWidth = 0;\r
+            while (borderWidth < minDimension && !image.isBlack(borderWidth, borderWidth)) {\r
+              borderWidth++;\r
+            }\r
+            if (borderWidth == minDimension) {\r
+              throw new ReaderException();\r
+            }\r
+\r
+            // And then keep tracking across the top-left black module to determine module size\r
+            int moduleEnd = borderWidth + 1;\r
+            while (moduleEnd < width && image.isBlack(moduleEnd, borderWidth)) {\r
+              moduleEnd++;\r
+            }\r
+            if (moduleEnd == width) {\r
+              throw new ReaderException();\r
+            }\r
+\r
+            int moduleSize = moduleEnd - borderWidth;\r
+\r
+            // And now find where the bottommost black module on the first column ends\r
+            int columnEndOfSymbol = height - 1;\r
+            while (columnEndOfSymbol >= 0 && !image.isBlack(borderWidth, columnEndOfSymbol)) {\r
+               columnEndOfSymbol--;\r
+            }\r
+            if (columnEndOfSymbol < 0) {\r
+              throw new ReaderException();\r
+            }\r
+            columnEndOfSymbol++;\r
+\r
+            // Make sure width of barcode is a multiple of module size\r
+            if ((columnEndOfSymbol - borderWidth) % moduleSize != 0) {\r
+              throw new ReaderException();\r
+            }\r
+            int dimension = (columnEndOfSymbol - borderWidth) / moduleSize;\r
+\r
+            // Push in the "border" by half the module width so that we start\r
+            // sampling in the middle of the module. Just in case the image is a\r
+            // little off, this will help recover.\r
+            borderWidth += moduleSize >> 1;\r
+\r
+            int sampleDimension = borderWidth + (dimension - 1) * moduleSize;\r
+            if (sampleDimension >= width || sampleDimension >= height) {\r
+              throw new ReaderException();\r
+            }\r
+\r
+            // Now just read off the bits\r
+            BitMatrix bits = new BitMatrix(dimension);\r
+            for (int i = 0; i < dimension; i++) {\r
+              int iOffset = borderWidth + i * moduleSize;\r
+              for (int j = 0; j < dimension; j++) {\r
+                if (image.isBlack(borderWidth + j * moduleSize, iOffset)) {\r
+                  bits.set(i, j);\r
+                }\r
+              }\r
+            }\r
+            return bits;\r
+          }\r
+    }\r
+}\r