Add check for minimal whitespace before/after Code 128, Code 39; a few code tweaks as well

git-svn-id: https://zxing.googlecode.com/svn/trunk@601 59b500cc-1b3d-0410-9834-0bbf25fbcc57

core/src/com/google/zxing/common/BitArray.java

@@ -107,14 +107,11 @@ public final class BitArray {
           mask |= 1 << j;
         }
       }
-      if (value) {
-        if ((bits[i] & mask) != mask) {
-          return false;
-        }
-      } else {
-        if ((bits[i] & mask) != 0) {
-          return false;
-        }
+
+      // Return false if we're looking for 1s and the masked bits[i] isn't all 1s (that is,
+      // equals the mask, or we're looking for 0s and the masked portion is not all 0s
+      if ((bits[i] & mask) != (value ? mask : 0)) {
+        return false;
       }
     }
     return true;

core/src/com/google/zxing/oned/AbstractUPCEANReader.java

@@ -93,8 +93,8 @@ public abstract class AbstractUPCEANReader extends AbstractOneDReader implements
       int start = startRange[0];
       nextStart = startRange[1];
       // As a check, we want to see some white in front of this "start pattern",
-      // maybe as wide as the start pattern itself?
-      foundStart = row.isRange(Math.max(0, start - (3 * (startRange[1] - start)) / 2), start, false);
+      // maybe as wide as the 150% of the start pattern itself?
+      foundStart = row.isRange(Math.max(0, start - (3 * (nextStart - start)) / 2), start, false);
     }
     return startRange;
   }
@@ -108,7 +108,7 @@ public abstract class AbstractUPCEANReader extends AbstractOneDReader implements
     int endStart = decodeMiddle(row, startGuardRange, result);
     int[] endRange = decodeEnd(row, endStart);
 
-    // Check for whitespace after the pattern
+    // Check for whitespace after the pattern -- 150% of size of end pattern
     int end = endRange[1];
     if (!row.isRange(end, Math.min(row.getSize(), end + (3 * (end - endRange[0])) / 2), false)) {
       throw new ReaderException("Pattern not followed by whitespace");

core/src/com/google/zxing/oned/Code128Reader.java

@@ -194,7 +194,10 @@ public final class Code128Reader extends AbstractOneDReader {
             }
           }
           if (bestMatch >= 0) {
-            return new int[]{patternStart, i, bestMatch};
+            // Look for whitespace before start pattern, >= 50% of width of start pattern            
+            if (row.isRange(Math.max(0, patternStart - (i - patternStart) / 2), patternStart, false)) {
+              return new int[]{patternStart, i, bestMatch};
+            }
           }
           patternStart += counters[0] + counters[1];
           for (int y = 2; y < patternLength; y++) {
@@ -413,6 +416,16 @@ public final class Code128Reader extends AbstractOneDReader {
 
     }
 
+    // Check for ample whitespice following pattern, but, to do this we first need to remember that we
+    // fudged decoding CODE_STOP since it actually has 7 bars, not 6. There is a black bar left to read off.
+    // Would be slightly better to properly read. Here we just skip it:
+    while (row.get(nextStart)) {
+      nextStart++;
+    }
+    if (!row.isRange(nextStart, Math.min(row.getSize(), nextStart + (nextStart - lastStart) / 2), false)) {
+      throw new ReaderException("Pattern not followed by whitespace");
+    }
+
     // Pull out from sum the value of the penultimate check code
     checksumTotal -= multiplier * lastCode;
     // lastCode is the checksum then:

core/src/com/google/zxing/oned/Code39Reader.java

@@ -26,7 +26,7 @@ import com.google.zxing.common.GenericResultPoint;
 import java.util.Hashtable;
 
 /**
- * <p>Decodes Code 39 barcodes. This does not supported "Full ASCII Code 39" yet.</p>
+ * <p>Decodes Code 39 barcodes. This does not support "Full ASCII Code 39" yet.</p>
  *
  * @author srowen@google.com (Sean Owen)
  */
@@ -122,6 +122,18 @@ public final class Code39Reader extends AbstractOneDReader {
     } while (decodedChar != '*');
     result.deleteCharAt(result.length() - 1); // remove asterisk
 
+    // Look for whitespace after pattern:
+    int lastPatternSize = 0;
+    for (int i = 0; i < counters.length; i++) {
+      lastPatternSize += counters[i];
+    }
+    int whiteSpaceAfterEnd = nextStart - lastStart - lastPatternSize;
+    // If 50% of last pattern size, following last pattern, is not whitespace, fail
+    // (but if it's whitespace to the very end of the image, that's OK)
+    if (nextStart != end && whiteSpaceAfterEnd / 2 < lastPatternSize) {
+      throw new ReaderException("Pattern not followed by whitespace");
+    }
+
     if (usingCheckDigit) {
       int max = result.length() - 1;
       int total = 0;
@@ -180,7 +192,10 @@ public final class Code39Reader extends AbstractOneDReader {
         if (counterPosition == patternLength - 1) {
           try {
             if (toNarrowWidePattern(counters) == ASTERISK_ENCODING) {
-              return new int[]{patternStart, i};
+              // Look for whitespace before start pattern, >= 50% of width of start pattern
+              if (row.isRange(Math.max(0, patternStart - (i - patternStart) / 2), patternStart, false)) {
+                return new int[]{patternStart, i};
+              }
             }
           } catch (ReaderException re) {
             // no match, continue