[SCM] Multi-format 1D/2D barcode image processing library branch, upstream, updated. 24d4480bc48cf9eabf7b2bd2f528248b0e458809
bas5winkel
bas5winkel at 59b500cc-1b3d-0410-9834-0bbf25fbcc57
Wed Aug 4 01:31:52 UTC 2010
The following commit has been merged in the upstream branch:
commit 27571bd77cf3f1e9e62b05443f9ab131547c2f5a
Author: bas5winkel <bas5winkel at 59b500cc-1b3d-0410-9834-0bbf25fbcc57>
Date: Tue Jun 1 14:39:24 2010 +0000
Changed validation method in order to prevent false positives on other 1D barcodes
git-svn-id: http://zxing.googlecode.com/svn/trunk@1407 59b500cc-1b3d-0410-9834-0bbf25fbcc57
diff --git a/core/src/com/google/zxing/oned/CodaBarReader.java b/core/src/com/google/zxing/oned/CodaBarReader.java
index a3382b6..703d947 100644
--- a/core/src/com/google/zxing/oned/CodaBarReader.java
+++ b/core/src/com/google/zxing/oned/CodaBarReader.java
@@ -45,11 +45,20 @@ public final class CodaBarReader extends OneDReader {
0x01A, 0x029 //TN
};
+ // minimal number of characters that should be present (inclusing start and stop characters)
+ // this check has been added to reduce the number of false positive on other formats
+ // until the cause for this behaviour has been determined
+ // under normal circumstances this should be set to 3
+ private static final int minCharacterLength = 6;
+
// multiple start/end patterns
// official start and end patterns
+ private static final char[] STARTEND_ENCODING = {'E', '*', 'A', 'B', 'C', 'D', 'T', 'N'};
// some codabar generator allow the codabar string to be closed by every character
- private static final char[] STARTEND_ENCODING = {
- '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '$', ':', '/', '.', '+', 'A', 'B', 'C', 'D', 'T', 'N'};
+ //private static final char[] STARTEND_ENCODING = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '$', ':', '/', '.', '+', 'A', 'B', 'C', 'D', 'T', 'N'};
+
+ // some industries use a checksum standard but this is not part of the original codabar standard
+ // for more information see : http://www.mecsw.com/specs/codabar.html
public Result decodeRow(int rowNumber, BitArray row, Hashtable hints) throws NotFoundException {
int[] start = findAsteriskPattern(row);
@@ -87,29 +96,12 @@ public final class CodaBarReader extends OneDReader {
}
} while (nextStart < end); // no fixed end pattern so keep on reading while data is available
- // find last character in STARTEND_ENCODING
- for (int k = result.length() - 1; k >= 0; k--) {
- if (arrayContains(STARTEND_ENCODING, result.charAt(k))) {
- // valid character -> remove and break out of loop
- result.deleteCharAt(k);
- k = -1;// break out of loop
- } else {
- // not a valid character -> remove anyway
- result.deleteCharAt(k);
- }
- }
-
-
- // remove first character
- if (result.length() > 0) {
- result.deleteCharAt(0);
- }
-
// 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)
@@ -117,17 +109,49 @@ public final class CodaBarReader extends OneDReader {
throw NotFoundException.getNotFoundInstance();
}
-
- String resultString = result.toString();
- if (resultString.length() == 0) {
- // Almost surely a false positive
- throw NotFoundException.getNotFoundInstance();
+ // valid result?
+ if (result.length() < 2)
+ {
+ throw NotFoundException.getNotFoundInstance();
+ }
+
+ char startchar = result.charAt(0);
+ if (!arrayContains(STARTEND_ENCODING, startchar))
+ {
+ //invalid start character
+ throw NotFoundException.getNotFoundInstance();
+ }
+
+ // find stop character
+ for (int k = 1;k < result.length() ;k++)
+ {
+ if (result.charAt(k) == startchar)
+ {
+ // found stop character -> discard rest of the string
+ if ((k+1) != result.length())
+ {
+ result.delete(k+1,result.length()-1);
+ k = result.length();// break out of loop
+ }
+ }
}
+ // remove stop/start characters character and check if a string longer than 5 characters is contained
+ if (result.length() > minCharacterLength)
+ {
+ result.deleteCharAt(result.length()-1);
+ result.deleteCharAt(0);
+ }
+ else
+ {
+ // Almost surely a false positive ( start + stop + at least 1 character)
+ throw NotFoundException.getNotFoundInstance();
+ }
+
float left = (float) (start[1] + start[0]) / 2.0f;
float right = (float) (nextStart + lastStart) / 2.0f;
return new Result(
- resultString,
+ result.toString(),
null,
new ResultPoint[]{
new ResultPoint(left, (float) rowNumber),
--
Multi-format 1D/2D barcode image processing library
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