1 files changed, 142 insertions, 0 deletions
diff --git a/qr_scanner/src/com/google/zxing/client/android/PlanarYUVLuminanceSource.java b/qr_scanner/src/com/google/zxing/client/android/PlanarYUVLuminanceSource.java
new file mode 100644
index 000000000..ed0a8a33f
--- /dev/null
+++ b/qr_scanner/src/com/google/zxing/client/android/PlanarYUVLuminanceSource.java
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.client.android;
+
+import com.google.zxing.LuminanceSource;
+
+import android.graphics.Bitmap;
+
+/**
+ * This object extends LuminanceSource around an array of YUV data returned from the camera driver,
+ * with the option to crop to a rectangle within the full data. This can be used to exclude
+ * superfluous pixels around the perimeter and speed up decoding.
+ *
+ * It works for any pixel format where the Y channel is planar and appears first, including
+ * YCbCr_420_SP and YCbCr_422_SP.
+ *
+ * @author dswitkin@google.com (Daniel Switkin)
+ */
+public final class PlanarYUVLuminanceSource extends LuminanceSource {
+
+  private final byte[] yuvData;
+  private final int dataWidth;
+  private final int dataHeight;
+  private final int left;
+  private final int top;
+
+  public PlanarYUVLuminanceSource(byte[] yuvData, int dataWidth, int dataHeight, int left, int top,
+      int width, int height, boolean reverseHorizontal) {
+    super(width, height);
+
+    if (left + width > dataWidth || top + height > dataHeight) {
+      throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
+    }
+
+    this.yuvData = yuvData;
+    this.dataWidth = dataWidth;
+    this.dataHeight = dataHeight;
+    this.left = left;
+    this.top = top;
+    if (reverseHorizontal) {
+      reverseHorizontal(width, height);
+    }
+  }
+
+  @Override
+  public byte[] getRow(int y, byte[] row) {
+    if (y < 0 || y >= getHeight()) {
+      throw new IllegalArgumentException("Requested row is outside the image: " + y);
+    }
+    int width = getWidth();
+    if (row == null || row.length < width) {
+      row = new byte[width];
+    }
+    int offset = (y + top) * dataWidth + left;
+    System.arraycopy(yuvData, offset, row, 0, width);
+    return row;
+  }
+
+  @Override
+  public byte[] getMatrix() {
+    int width = getWidth();
+    int height = getHeight();
+
+    // If the caller asks for the entire underlying image, save the copy and give them the
+    // original data. The docs specifically warn that result.length must be ignored.
+    if (width == dataWidth && height == dataHeight) {
+      return yuvData;
+    }
+
+    int area = width * height;
+    byte[] matrix = new byte[area];
+    int inputOffset = top * dataWidth + left;
+
+    // If the width matches the full width of the underlying data, perform a single copy.
+    if (width == dataWidth) {
+      System.arraycopy(yuvData, inputOffset, matrix, 0, area);
+      return matrix;
+    }
+
+    // Otherwise copy one cropped row at a time.
+    byte[] yuv = yuvData;
+    for (int y = 0; y < height; y++) {
+      int outputOffset = y * width;
+      System.arraycopy(yuv, inputOffset, matrix, outputOffset, width);
+      inputOffset += dataWidth;
+    }
+    return matrix;
+  }
+
+  @Override
+  public boolean isCropSupported() {
+    return true;
+  }
+
+  public Bitmap renderCroppedGreyscaleBitmap() {
+    int width = getWidth();
+    int height = getHeight();
+    int[] pixels = new int[width * height];
+    byte[] yuv = yuvData;
+    int inputOffset = top * dataWidth + left;
+
+    for (int y = 0; y < height; y++) {
+      int outputOffset = y * width;
+      for (int x = 0; x < width; x++) {
+        int grey = yuv[inputOffset + x] & 0xff;
+        pixels[outputOffset + x] = 0xFF000000 | (grey * 0x00010101);
+      }
+      inputOffset += dataWidth;
+    }
+
+    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+    bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
+    return bitmap;
+  }
+
+  private void reverseHorizontal(int width, int height) {
+    byte[] yuvData = this.yuvData;
+    for (int y = 0, rowStart = top * dataWidth + left; y < height; y++, rowStart += dataWidth) {
+      int middle = rowStart + width / 2;
+      for (int x1 = rowStart, x2 = rowStart + width - 1; x1 < middle; x1++, x2--) {
+        byte temp = yuvData[x1];
+        yuvData[x1] = yuvData[x2];
+        yuvData[x2] = temp;
+      }
+    }
+  }
+
+}