Fix typo in method "isRotate*d*Supported"; don't attempt to rotate images of unknown...

[zxing.git] / javame / src / com / google / zxing / client / j2me / LCDUIImageMonochromeBitmapSource.java

diff --git a/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java b/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java
index 1645628..fbbf0da 100644 (file)
--- a/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java
+++ b/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java
@@ -16,8 +16,8 @@
 
 package com.google.zxing.client.j2me;
 
-import com.google.zxing.MonochromeBitmapSource;
 import com.google.zxing.BlackPointEstimationMethod;
+import com.google.zxing.MonochromeBitmapSource;
 import com.google.zxing.common.BitArray;
 import com.google.zxing.common.BlackPointEstimator;
 
@@ -25,23 +25,30 @@ import javax.microedition.lcdui.Image;
 
 /**
  * <p>An implementation based on Java ME's {@link Image} representation.</p>
- * 
+ *
  * @author Sean Owen (srowen@google.com), Daniel Switkin (dswitkin@google.com)
  */
-final class LCDUIImageMonochromeBitmapSource implements MonochromeBitmapSource {
+public final class LCDUIImageMonochromeBitmapSource implements MonochromeBitmapSource {
 
   private final int[] rgbPixels;
   private final int width;
   private final int height;
   private int blackPoint;
   private BlackPointEstimationMethod lastMethod;
+  private int lastArgument;
 
-  LCDUIImageMonochromeBitmapSource(final Image image) {
+  private static final int LUMINANCE_BITS = 5;
+  private static final int LUMINANCE_SHIFT = 8 - LUMINANCE_BITS;
+  private static final int LUMINANCE_BUCKETS = 1 << LUMINANCE_BITS;
+
+  public LCDUIImageMonochromeBitmapSource(Image image) {
     width = image.getWidth();
     height = image.getHeight();
     rgbPixels = new int[width * height];
     image.getRGB(rgbPixels, 0, width, 0, 0, width, height);
     blackPoint = 0x7F;
+    lastMethod = null;
+    lastArgument = 0;
   }
 
   public boolean isBlack(int x, int y) {
@@ -71,27 +78,44 @@ final class LCDUIImageMonochromeBitmapSource implements MonochromeBitmapSource {
   }
 
   public void estimateBlackPoint(BlackPointEstimationMethod method, int argument) {
-    if (method.equals(BlackPointEstimationMethod.TWO_D_SAMPLING)) {
-      if (!BlackPointEstimationMethod.TWO_D_SAMPLING.equals(lastMethod)) {
-        int[] luminanceBuckets = new int[32];
+    if (!method.equals(lastMethod) || argument != lastArgument) {
+      int[] histogram = new int[LUMINANCE_BUCKETS];
+      float biasTowardsWhite = 1.0f;
+      if (method.equals(BlackPointEstimationMethod.TWO_D_SAMPLING)) {
         int minDimension = width < height ? width : height;
         for (int n = 0, offset = 0; n < minDimension; n++, offset += width + 1) {
-          luminanceBuckets[computeRGBLuminance(rgbPixels[offset]) >> 3]++;
+          histogram[computeRGBLuminance(rgbPixels[offset]) >> LUMINANCE_SHIFT]++;
+        }
+      } else if (method.equals(BlackPointEstimationMethod.ROW_SAMPLING)) {
+        if (argument < 0 || argument >= height) {
+          throw new IllegalArgumentException("Row is not within the image: " + argument);
+        }
+        biasTowardsWhite = 2.0f;
+        int offset = argument * width;
+        for (int x = 0; x < width; x++) {
+          histogram[computeRGBLuminance(rgbPixels[offset + x]) >> LUMINANCE_SHIFT]++;
         }
-        blackPoint = BlackPointEstimator.estimate(luminanceBuckets) << 3;
+      } else {
+        throw new IllegalArgumentException("Unknown method: " + method);
       }
-    } else if (method.equals(BlackPointEstimationMethod.ROW_SAMPLING)) {
-      // TODO
-    } else {
-      throw new IllegalArgumentException("Unknown method: " + method);
+      blackPoint = BlackPointEstimator.estimate(histogram, biasTowardsWhite) << LUMINANCE_SHIFT;
+      lastMethod = method;
+      lastArgument = argument;
     }
-    lastMethod = method;
   }
 
   public BlackPointEstimationMethod getLastEstimationMethod() {
     return lastMethod;
   }
 
+  public MonochromeBitmapSource rotateCounterClockwise() {
+    throw new IllegalStateException("Rotate not supported");
+  }
+
+  public boolean isRotateSupported() {
+    return false;
+  }
+
   /**
    * Extracts luminance from a pixel from this source. By default, the source is assumed to use RGB,
    * so this implementation computes luminance is a function of a red, green and blue components as