/*
|
* Copyright 2012 ZXing authors
|
*
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
* you may not use this file except in compliance with the License.
|
* You may obtain a copy of the License at
|
*
|
* http://www.apache.org/licenses/LICENSE-2.0
|
*
|
* Unless required by applicable law or agreed to in writing, software
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
* See the License for the specific language governing permissions and
|
* limitations under the License.
|
*/
|
|
#import "ZXAbstractRSSReader.h"
|
#import "ZXIntArray.h"
|
|
static float ZX_RSS_MAX_AVG_VARIANCE = 0.2f;
|
static float ZX_RSS_MAX_INDIVIDUAL_VARIANCE = 0.45f;
|
|
float const ZX_RSS_MIN_FINDER_PATTERN_RATIO = 9.5f / 12.0f;
|
float const ZX_RSS_MAX_FINDER_PATTERN_RATIO = 12.5f / 14.0f;
|
|
#define ZX_RSS14_FINDER_PATTERNS_LEN 9
|
#define ZX_RSS14_FINDER_PATTERNS_SUB_LEN 4
|
const int ZX_RSS14_FINDER_PATTERNS[ZX_RSS14_FINDER_PATTERNS_LEN][ZX_RSS14_FINDER_PATTERNS_SUB_LEN] = {
|
{3,8,2,1},
|
{3,5,5,1},
|
{3,3,7,1},
|
{3,1,9,1},
|
{2,7,4,1},
|
{2,5,6,1},
|
{2,3,8,1},
|
{1,5,7,1},
|
{1,3,9,1},
|
};
|
|
#define ZX_RSS_EXPANDED_FINDER_PATTERNS_LEN 6
|
#define ZX_RSS_EXPANDED_FINDER_PATTERNS_SUB_LEN 4
|
const int ZX_RSS_EXPANDED_FINDER_PATTERNS[ZX_RSS_EXPANDED_FINDER_PATTERNS_LEN][ZX_RSS_EXPANDED_FINDER_PATTERNS_SUB_LEN] = {
|
{1,8,4,1}, // A
|
{3,6,4,1}, // B
|
{3,4,6,1}, // C
|
{3,2,8,1}, // D
|
{2,6,5,1}, // E
|
{2,2,9,1} // F
|
};
|
|
@implementation ZXAbstractRSSReader
|
|
- (id)init {
|
if (self = [super init]) {
|
_decodeFinderCounters = [[ZXIntArray alloc] initWithLength:4];
|
_dataCharacterCounters = [[ZXIntArray alloc] initWithLength:8];
|
|
_oddRoundingErrorsLen = 4;
|
_oddRoundingErrors = (float *)malloc(_oddRoundingErrorsLen * sizeof(float));
|
memset(_oddRoundingErrors, 0, _oddRoundingErrorsLen * sizeof(float));
|
|
_evenRoundingErrorsLen = 4;
|
_evenRoundingErrors = (float *)malloc(_evenRoundingErrorsLen * sizeof(float));
|
memset(_evenRoundingErrors, 0, _evenRoundingErrorsLen * sizeof(float));
|
|
_oddCounts = [[ZXIntArray alloc] initWithLength:_dataCharacterCounters.length / 2];
|
_evenCounts = [[ZXIntArray alloc] initWithLength:_dataCharacterCounters.length / 2];
|
}
|
|
return self;
|
}
|
|
- (void)dealloc {
|
if (_oddRoundingErrors != NULL) {
|
free(_oddRoundingErrors);
|
_oddRoundingErrors = NULL;
|
}
|
|
if (_evenRoundingErrors != NULL) {
|
free(_evenRoundingErrors);
|
_evenRoundingErrors = NULL;
|
}
|
}
|
|
+ (int)parseFinderValue:(ZXIntArray *)counters finderPatternType:(ZX_RSS_PATTERNS)finderPatternType {
|
switch (finderPatternType) {
|
case ZX_RSS_PATTERNS_RSS14_PATTERNS:
|
for (int value = 0; value < ZX_RSS14_FINDER_PATTERNS_LEN; value++) {
|
if ([self patternMatchVariance:counters pattern:ZX_RSS14_FINDER_PATTERNS[value] maxIndividualVariance:ZX_RSS_MAX_INDIVIDUAL_VARIANCE] < ZX_RSS_MAX_AVG_VARIANCE) {
|
return value;
|
}
|
}
|
break;
|
|
case ZX_RSS_PATTERNS_RSS_EXPANDED_PATTERNS:
|
for (int value = 0; value < ZX_RSS_EXPANDED_FINDER_PATTERNS_LEN; value++) {
|
if ([self patternMatchVariance:counters pattern:ZX_RSS_EXPANDED_FINDER_PATTERNS[value] maxIndividualVariance:ZX_RSS_MAX_INDIVIDUAL_VARIANCE] < ZX_RSS_MAX_AVG_VARIANCE) {
|
return value;
|
}
|
}
|
break;
|
|
default:
|
break;
|
}
|
|
return -1;
|
}
|
|
+ (int)count:(ZXIntArray *)array {
|
return [array sum];
|
}
|
|
+ (void)increment:(ZXIntArray *)array errors:(float *)errors {
|
int index = 0;
|
float biggestError = errors[0];
|
for (int i = 1; i < array.length; i++) {
|
if (errors[i] > biggestError) {
|
biggestError = errors[i];
|
index = i;
|
}
|
}
|
array.array[index]++;
|
}
|
|
+ (void)decrement:(ZXIntArray *)array errors:(float *)errors {
|
int index = 0;
|
float biggestError = errors[0];
|
for (int i = 1; i < array.length; i++) {
|
if (errors[i] < biggestError) {
|
biggestError = errors[i];
|
index = i;
|
}
|
}
|
array.array[index]--;
|
}
|
|
+ (BOOL)isFinderPattern:(ZXIntArray *)counters {
|
int32_t *array = counters.array;
|
int firstTwoSum = array[0] + array[1];
|
int sum = firstTwoSum + array[2] + array[3];
|
float ratio = (float)firstTwoSum / (float)sum;
|
if (ratio >= ZX_RSS_MIN_FINDER_PATTERN_RATIO && ratio <= ZX_RSS_MAX_FINDER_PATTERN_RATIO) {
|
int minCounter = INT_MAX;
|
int maxCounter = INT_MIN;
|
for (int i = 0; i < counters.length; i++) {
|
int counter = array[i];
|
if (counter > maxCounter) {
|
maxCounter = counter;
|
}
|
if (counter < minCounter) {
|
minCounter = counter;
|
}
|
}
|
|
return maxCounter < 10 * minCounter;
|
}
|
return NO;
|
}
|
|
@end
|
