On scan we pass a grayscale image of the scanned image, which is used as a thumbnail. These days this is getting to be 2MB of data to bundle to copy around in memory. Instead scale by 50% and JPEG-encode. This saves some memory and paves the way for later perhaps saving the image data with history.

git-svn-id: https://zxing.googlecode.com/svn/trunk@2561 59b500cc-1b3d-0410-9834-0bbf25fbcc57

android/src/com/google/zxing/client/android/CaptureActivity.java

@@ -399,9 +399,10 @@ public final class CaptureActivity extends Activity implements SurfaceHolder.Cal
    * A valid barcode has been found, so give an indication of success and show the results.
    *
    * @param rawResult The contents of the barcode.
+   * @param scaleFactor amount by which thumbnail was scaled
    * @param barcode   A greyscale bitmap of the camera data which was decoded.
    */
-  public void handleDecode(Result rawResult, Bitmap barcode) {
+  public void handleDecode(Result rawResult, Bitmap barcode, float scaleFactor) {
     inactivityTimer.onActivity();
     lastResult = rawResult;
     ResultHandler resultHandler = ResultHandlerFactory.makeResultHandler(this, rawResult);
@@ -411,7 +412,7 @@ public final class CaptureActivity extends Activity implements SurfaceHolder.Cal
       historyManager.addHistoryItem(rawResult, resultHandler);
       // Then not from history, so beep/vibrate and we have an image to draw on
       beepManager.playBeepSoundAndVibrate();
-      drawResultPoints(barcode, rawResult);
+      drawResultPoints(barcode, scaleFactor, rawResult);
     }
 
     switch (source) {
@@ -445,9 +446,10 @@ public final class CaptureActivity extends Activity implements SurfaceHolder.Cal
    * Superimpose a line for 1D or dots for 2D to highlight the key features of the barcode.
    *
    * @param barcode   A bitmap of the captured image.
+   * @param scaleFactor amount by which thumbnail was scaled
    * @param rawResult The decoded results which contains the points to draw.
    */
-  private void drawResultPoints(Bitmap barcode, Result rawResult) {
+  private void drawResultPoints(Bitmap barcode, float scaleFactor, Result rawResult) {
     ResultPoint[] points = rawResult.getResultPoints();
     if (points != null && points.length > 0) {
       Canvas canvas = new Canvas(barcode);
@@ -455,24 +457,28 @@ public final class CaptureActivity extends Activity implements SurfaceHolder.Cal
       paint.setColor(getResources().getColor(R.color.result_points));
       if (points.length == 2) {
         paint.setStrokeWidth(4.0f);
-        drawLine(canvas, paint, points[0], points[1]);
+        drawLine(canvas, paint, points[0], points[1], scaleFactor);
       } else if (points.length == 4 &&
                  (rawResult.getBarcodeFormat() == BarcodeFormat.UPC_A ||
                   rawResult.getBarcodeFormat() == BarcodeFormat.EAN_13)) {
         // Hacky special case -- draw two lines, for the barcode and metadata
-        drawLine(canvas, paint, points[0], points[1]);
+        drawLine(canvas, paint, points[0], points[1], scaleFactor);
-        drawLine(canvas, paint, points[2], points[3]);
+        drawLine(canvas, paint, points[2], points[3], scaleFactor);
       } else {
         paint.setStrokeWidth(10.0f);
         for (ResultPoint point : points) {
-          canvas.drawPoint(point.getX(), point.getY(), paint);
+          canvas.drawPoint(scaleFactor * point.getX(), scaleFactor * point.getY(), paint);
         }
       }
     }
   }
 
-  private static void drawLine(Canvas canvas, Paint paint, ResultPoint a, ResultPoint b) {
+  private static void drawLine(Canvas canvas, Paint paint, ResultPoint a, ResultPoint b, float scaleFactor) {
-    canvas.drawLine(a.getX(), a.getY(), b.getX(), b.getY(), paint);
+    canvas.drawLine(scaleFactor * a.getX(), 
+                    scaleFactor * a.getY(), 
+                    scaleFactor * b.getX(), 
+                    scaleFactor * b.getY(), 
+                    paint);
   }
 
   // Put up our own UI for how to handle the decoded contents.

android/src/com/google/zxing/client/android/CaptureActivityHandler.java

@@ -19,6 +19,7 @@ package com.google.zxing.client.android;
 import android.content.ActivityNotFoundException;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
+import android.graphics.BitmapFactory;
 import android.provider.Browser;
 import com.google.zxing.BarcodeFormat;
 import com.google.zxing.Result;
@@ -82,9 +83,18 @@ public final class CaptureActivityHandler extends Handler {
         Log.d(TAG, "Got decode succeeded message");
         state = State.SUCCESS;
         Bundle bundle = message.getData();
-        Bitmap barcode = bundle == null ? null :
+        Bitmap barcode = null;
-            (Bitmap) bundle.getParcelable(DecodeThread.BARCODE_BITMAP);
+        float scaleFactor = 1.0f;
-        activity.handleDecode((Result) message.obj, barcode);
+        if (bundle != null) {
+          byte[] compressedBitmap = bundle.getByteArray(DecodeThread.BARCODE_BITMAP);
+          if (compressedBitmap != null) {
+            BitmapFactory.Options options = new BitmapFactory.Options();
+            options.inMutable = true;
+            barcode = BitmapFactory.decodeByteArray(compressedBitmap, 0, compressedBitmap.length, options);
+          }
+          scaleFactor = bundle.getFloat(DecodeThread.BARCODE_SCALED_FACTOR);          
+        }
+        activity.handleDecode((Result) message.obj, barcode, scaleFactor);
         break;
       case R.id.decode_failed:
         // We're decoding as fast as possible, so when one decode fails, start another.

android/src/com/google/zxing/client/android/DecodeHandler.java

@@ -19,7 +19,6 @@ package com.google.zxing.client.android;
 import android.graphics.Bitmap;
 import com.google.zxing.BinaryBitmap;
 import com.google.zxing.DecodeHintType;
-import com.google.zxing.LuminanceSource;
 import com.google.zxing.MultiFormatReader;
 import com.google.zxing.PlanarYUVLuminanceSource;
 import com.google.zxing.ReaderException;
@@ -32,6 +31,7 @@ import android.os.Looper;
 import android.os.Message;
 import android.util.Log;
 
+import java.io.ByteArrayOutputStream;
 import java.util.Map;
 
 final class DecodeHandler extends Handler {
@@ -95,8 +95,7 @@ final class DecodeHandler extends Handler {
       if (handler != null) {
         Message message = Message.obtain(handler, R.id.decode_succeeded, rawResult);
         Bundle bundle = new Bundle();
-        Bitmap grayscaleBitmap = toBitmap(source, source.renderCroppedGreyscaleBitmap());
+        bundleThumbnail(source, bundle);        
-        bundle.putParcelable(DecodeThread.BARCODE_BITMAP, grayscaleBitmap);
         message.setData(bundle);
         message.sendToTarget();
       }
@@ -108,12 +107,15 @@ final class DecodeHandler extends Handler {
     }
   }
 
-  private static Bitmap toBitmap(LuminanceSource source, int[] pixels) {
+  private static void bundleThumbnail(PlanarYUVLuminanceSource source, Bundle bundle) {
-    int width = source.getWidth();
+    int[] pixels = source.renderThumbnail();
-    int height = source.getHeight();
+    int width = source.getThumbnailWidth();
-    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+    int height = source.getThumbnailHeight();
-    bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
+    Bitmap bitmap = Bitmap.createBitmap(pixels, 0, width, width, height, Bitmap.Config.ARGB_8888);
-    return bitmap;
+    ByteArrayOutputStream out = new ByteArrayOutputStream();    
+    bitmap.compress(Bitmap.CompressFormat.JPEG, 50, out);
+    bundle.putByteArray(DecodeThread.BARCODE_BITMAP, out.toByteArray());
+    bundle.putFloat(DecodeThread.BARCODE_SCALED_FACTOR, (float) width / source.getWidth());
   }
 
 }

android/src/com/google/zxing/client/android/DecodeThread.java

@@ -39,6 +39,7 @@ import java.util.concurrent.CountDownLatch;
 final class DecodeThread extends Thread {
 
   public static final String BARCODE_BITMAP = "barcode_bitmap";
+  public static final String BARCODE_SCALED_FACTOR = "barcode_scaled_factor";
 
   private final CaptureActivity activity;
   private final Map<DecodeHintType,Object> hints;

core/src/com/google/zxing/PlanarYUVLuminanceSource.java

@@ -28,6 +28,8 @@ package com.google.zxing;
  */
 public final class PlanarYUVLuminanceSource extends LuminanceSource {
 
+  private static final int THUMBNAIL_SCALE_FACTOR = 2;
+  
   private final byte[] yuvData;
   private final int dataWidth;
   private final int dataHeight;
@@ -120,9 +122,9 @@ public final class PlanarYUVLuminanceSource extends LuminanceSource {
                                         false);
   }
 
-  public int[] renderCroppedGreyscaleBitmap() {
+  public int[] renderThumbnail() {
-    int width = getWidth();
+    int width = getWidth() / THUMBNAIL_SCALE_FACTOR;
-    int height = getHeight();
+    int height = getHeight() / THUMBNAIL_SCALE_FACTOR;
     int[] pixels = new int[width * height];
     byte[] yuv = yuvData;
     int inputOffset = top * dataWidth + left;
@@ -130,14 +132,28 @@ public final class PlanarYUVLuminanceSource extends LuminanceSource {
     for (int y = 0; y < height; y++) {
       int outputOffset = y * width;
       for (int x = 0; x < width; x++) {
-        int grey = yuv[inputOffset + x] & 0xff;
+        int grey = yuv[inputOffset + x * THUMBNAIL_SCALE_FACTOR] & 0xff;
         pixels[outputOffset + x] = 0xFF000000 | (grey * 0x00010101);
       }
-      inputOffset += dataWidth;
+      inputOffset += dataWidth * THUMBNAIL_SCALE_FACTOR;
     }
     return pixels;
   }
   
+  /**
+   * @return width of image from {@link #renderThumbnail()}
+   */
+  public int getThumbnailWidth() {
+    return getWidth() / THUMBNAIL_SCALE_FACTOR;
+  }
+  
+  /**
+   * @return height of image from {@link #renderThumbnail()}
+   */  
+  public int getThumbnailHeight() {
+    return getHeight() / THUMBNAIL_SCALE_FACTOR;
+  }
+
   private void reverseHorizontal(int width, int height) {
     byte[] yuvData = this.yuvData;
     for (int y = 0, rowStart = top * dataWidth + left; y < height; y++, rowStart += dataWidth) {