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Eliminated up to 700 execeptions being thrown per image by changing one method to return -1 on failure.

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git-svn-id: https://zxing.googlecode.com/svn/trunk@1154 59b500cc-1b3d-0410-9834-0bbf25fbcc57
This commit is contained in:
dswitkin 2009-12-13 16:58:28 +00:00
parent 01792f7460
commit fbff1b9718
1 changed files with 12 additions and 11 deletions
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23
core/src/com/google/zxing/oned/Code39Reader.java
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@ -106,6 +106,9 @@ public final class Code39Reader extends OneDReader {
do { do {
recordPattern(row, nextStart, counters); recordPattern(row, nextStart, counters);
int pattern = toNarrowWidePattern(counters); int pattern = toNarrowWidePattern(counters);
if (pattern < 0) {
throw ReaderException.getInstance();
}
decodedChar = patternToChar(pattern); decodedChar = patternToChar(pattern);
result.append(decodedChar); result.append(decodedChar);
lastStart = nextStart; lastStart = nextStart;
@ -187,15 +190,11 @@ public final class Code39Reader extends OneDReader {
counters[counterPosition]++; counters[counterPosition]++;
} else { } else {
if (counterPosition == patternLength - 1) { if (counterPosition == patternLength - 1) {
try { if (toNarrowWidePattern(counters) == ASTERISK_ENCODING) {
if (toNarrowWidePattern(counters) == ASTERISK_ENCODING) { // Look for whitespace before start pattern, >= 50% of width of start pattern
// Look for whitespace before start pattern, >= 50% of width of start pattern if (row.isRange(Math.max(0, patternStart - (i - patternStart) / 2), patternStart, false)) {
if (row.isRange(Math.max(0, patternStart - (i - patternStart) / 2), patternStart, false)) { return new int[]{patternStart, i};
return new int[]{patternStart, i};
}
} }
} catch (ReaderException re) {
// no match, continue
} }
patternStart += counters[0] + counters[1]; patternStart += counters[0] + counters[1];
for (int y = 2; y < patternLength; y++) { for (int y = 2; y < patternLength; y++) {
@ -214,7 +213,9 @@ public final class Code39Reader extends OneDReader {
throw ReaderException.getInstance(); throw ReaderException.getInstance();
} }
private static int toNarrowWidePattern(int[] counters) throws ReaderException { // For efficiency, returns -1 on failure. Not throwing here saved as many as 700 exceptions
// per image when using some of our blackbox images.
private static int toNarrowWidePattern(int[] counters) {
int numCounters = counters.length; int numCounters = counters.length;
int maxNarrowCounter = 0; int maxNarrowCounter = 0;
int wideCounters; int wideCounters;
@ -248,14 +249,14 @@ public final class Code39Reader extends OneDReader {
wideCounters--; wideCounters--;
// totalWideCountersWidth = 3 * average, so this checks if counter >= 3/2 * average // totalWideCountersWidth = 3 * average, so this checks if counter >= 3/2 * average
if ((counter << 1) >= totalWideCountersWidth) { if ((counter << 1) >= totalWideCountersWidth) {
throw ReaderException.getInstance(); return -1;
} }
} }
} }
return pattern; return pattern;
} }
} while (wideCounters > 3); } while (wideCounters > 3);
throw ReaderException.getInstance(); return -1;
} }
private static char patternToChar(int pattern) throws ReaderException { private static char patternToChar(int pattern) throws ReaderException {