/*
|
* 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 "ZXBitArray.h"
|
#import "ZXDecodeHints.h"
|
#import "ZXEANManufacturerOrgSupport.h"
|
#import "ZXErrors.h"
|
#import "ZXIntArray.h"
|
#import "ZXResult.h"
|
#import "ZXResultPoint.h"
|
#import "ZXResultPointCallback.h"
|
#import "ZXUPCEANReader.h"
|
#import "ZXUPCEANExtensionSupport.h"
|
|
static float ZX_UPC_EAN_MAX_AVG_VARIANCE = 0.48f;
|
static float ZX_UPC_EAN_MAX_INDIVIDUAL_VARIANCE = 0.7f;
|
|
/**
|
* Start/end guard pattern.
|
*/
|
const int ZX_UPC_EAN_START_END_PATTERN_LEN = 3;
|
const int ZX_UPC_EAN_START_END_PATTERN[ZX_UPC_EAN_START_END_PATTERN_LEN] = {1, 1, 1};
|
|
/**
|
* Pattern marking the middle of a UPC/EAN pattern, separating the two halves.
|
*/
|
const int ZX_UPC_EAN_MIDDLE_PATTERN_LEN = 5;
|
const int ZX_UPC_EAN_MIDDLE_PATTERN[ZX_UPC_EAN_MIDDLE_PATTERN_LEN] = {1, 1, 1, 1, 1};
|
|
/**
|
* "Odd", or "L" patterns used to encode UPC/EAN digits.
|
*/
|
const int ZX_UPC_EAN_L_PATTERNS_LEN = 10;
|
const int ZX_UPC_EAN_L_PATTERNS_SUB_LEN = 4;
|
const int ZX_UPC_EAN_L_PATTERNS[ZX_UPC_EAN_L_PATTERNS_LEN][ZX_UPC_EAN_L_PATTERNS_SUB_LEN] = {
|
{3, 2, 1, 1}, // 0
|
{2, 2, 2, 1}, // 1
|
{2, 1, 2, 2}, // 2
|
{1, 4, 1, 1}, // 3
|
{1, 1, 3, 2}, // 4
|
{1, 2, 3, 1}, // 5
|
{1, 1, 1, 4}, // 6
|
{1, 3, 1, 2}, // 7
|
{1, 2, 1, 3}, // 8
|
{3, 1, 1, 2} // 9
|
};
|
|
/**
|
* As above but also including the "even", or "G" patterns used to encode UPC/EAN digits.
|
*/
|
const int ZX_UPC_EAN_L_AND_G_PATTERNS_LEN = 20;
|
const int ZX_UPC_EAN_L_AND_G_PATTERNS_SUB_LEN = 4;
|
const int ZX_UPC_EAN_L_AND_G_PATTERNS[ZX_UPC_EAN_L_AND_G_PATTERNS_LEN][ZX_UPC_EAN_L_AND_G_PATTERNS_SUB_LEN] = {
|
{3, 2, 1, 1}, // 0
|
{2, 2, 2, 1}, // 1
|
{2, 1, 2, 2}, // 2
|
{1, 4, 1, 1}, // 3
|
{1, 1, 3, 2}, // 4
|
{1, 2, 3, 1}, // 5
|
{1, 1, 1, 4}, // 6
|
{1, 3, 1, 2}, // 7
|
{1, 2, 1, 3}, // 8
|
{3, 1, 1, 2}, // 9
|
{1, 1, 2, 3}, // 10 reversed 0
|
{1, 2, 2, 2}, // 11 reversed 1
|
{2, 2, 1, 2}, // 12 reversed 2
|
{1, 1, 4, 1}, // 13 reversed 3
|
{2, 3, 1, 1}, // 14 reversed 4
|
{1, 3, 2, 1}, // 15 reversed 5
|
{4, 1, 1, 1}, // 16 reversed 6
|
{2, 1, 3, 1}, // 17 reversed 7
|
{3, 1, 2, 1}, // 18 reversed 8
|
{2, 1, 1, 3} // 19 reversed 9
|
};
|
|
@interface ZXUPCEANReader ()
|
|
@property (nonatomic, strong, readonly) NSMutableString *decodeRowNSMutableString;
|
@property (nonatomic, strong, readonly) ZXUPCEANExtensionSupport *extensionReader;
|
@property (nonatomic, strong, readonly) ZXEANManufacturerOrgSupport *eanManSupport;
|
|
@end
|
|
@implementation ZXUPCEANReader
|
|
- (id)init {
|
if (self = [super init]) {
|
_decodeRowNSMutableString = [NSMutableString stringWithCapacity:20];
|
_extensionReader = [[ZXUPCEANExtensionSupport alloc] init];
|
_eanManSupport = [[ZXEANManufacturerOrgSupport alloc] init];
|
}
|
|
return self;
|
}
|
|
+ (NSRange)findStartGuardPattern:(ZXBitArray *)row error:(NSError **)error {
|
BOOL foundStart = NO;
|
NSRange startRange = NSMakeRange(NSNotFound, 0);
|
int nextStart = 0;
|
ZXIntArray *counters = [[ZXIntArray alloc] initWithLength:ZX_UPC_EAN_START_END_PATTERN_LEN];
|
while (!foundStart) {
|
[counters clear];
|
startRange = [self findGuardPattern:row rowOffset:nextStart
|
whiteFirst:NO
|
pattern:ZX_UPC_EAN_START_END_PATTERN
|
patternLen:ZX_UPC_EAN_START_END_PATTERN_LEN
|
counters:counters
|
error:error];
|
if (startRange.location == NSNotFound) {
|
return startRange;
|
}
|
int start = (int)startRange.location;
|
nextStart = (int)NSMaxRange(startRange);
|
// Make sure there is a quiet zone at least as big as the start pattern before the barcode.
|
// If this check would run off the left edge of the image, do not accept this barcode,
|
// as it is very likely to be a false positive.
|
int quietStart = start - (nextStart - start);
|
if (quietStart >= 0) {
|
foundStart = [row isRange:quietStart end:start value:NO];
|
}
|
}
|
return startRange;
|
}
|
|
- (ZXResult *)decodeRow:(int)rowNumber row:(ZXBitArray *)row hints:(ZXDecodeHints *)hints error:(NSError **)error {
|
return [self decodeRow:rowNumber row:row startGuardRange:[[self class] findStartGuardPattern:row error:error] hints:hints error:error];
|
}
|
|
- (ZXResult *)decodeRow:(int)rowNumber row:(ZXBitArray *)row startGuardRange:(NSRange)startGuardRange hints:(ZXDecodeHints *)hints error:(NSError **)error {
|
id<ZXResultPointCallback> resultPointCallback = hints == nil ? nil : hints.resultPointCallback;
|
|
if (resultPointCallback != nil) {
|
[resultPointCallback foundPossibleResultPoint:[[ZXResultPoint alloc] initWithX:(startGuardRange.location + NSMaxRange(startGuardRange)) / 2.0f y:rowNumber]];
|
}
|
|
NSMutableString *result = [NSMutableString string];
|
int endStart = [self decodeMiddle:row startRange:startGuardRange result:result error:error];
|
if (endStart == -1) {
|
return nil;
|
}
|
|
if (resultPointCallback != nil) {
|
[resultPointCallback foundPossibleResultPoint:[[ZXResultPoint alloc] initWithX:endStart y:rowNumber]];
|
}
|
|
NSRange endRange = [self decodeEnd:row endStart:endStart error:error];
|
if (endRange.location == NSNotFound) {
|
return nil;
|
}
|
|
if (resultPointCallback != nil) {
|
[resultPointCallback foundPossibleResultPoint:[[ZXResultPoint alloc] initWithX:(endRange.location + NSMaxRange(endRange)) / 2.0f y:rowNumber]];
|
}
|
|
// Make sure there is a quiet zone at least as big as the end pattern after the barcode. The
|
// spec might want more whitespace, but in practice this is the maximum we can count on.
|
int end = (int)NSMaxRange(endRange);
|
int quietEnd = end + (end - (int)endRange.location);
|
if (quietEnd >= [row size] || ![row isRange:end end:quietEnd value:NO]) {
|
if (error) *error = ZXNotFoundErrorInstance();
|
return nil;
|
}
|
|
NSString *resultString = [result description];
|
// UPC/EAN should never be less than 8 chars anyway
|
if ([resultString length] < 8) {
|
if (error) *error = ZXFormatErrorInstance();
|
return nil;
|
}
|
if (![self checkChecksum:resultString error:error]) {
|
if (error) *error = ZXChecksumErrorInstance();
|
return nil;
|
}
|
|
float left = (float)(NSMaxRange(startGuardRange) + startGuardRange.location) / 2.0f;
|
float right = (float)(NSMaxRange(endRange) + endRange.location) / 2.0f;
|
ZXBarcodeFormat format = [self barcodeFormat];
|
|
ZXResult *decodeResult = [ZXResult resultWithText:resultString
|
rawBytes:nil
|
resultPoints:@[[[ZXResultPoint alloc] initWithX:left y:(float)rowNumber], [[ZXResultPoint alloc] initWithX:right y:(float)rowNumber]]
|
format:format];
|
|
int extensionLength = 0;
|
|
ZXResult *extensionResult = [self.extensionReader decodeRow:rowNumber row:row rowOffset:(int)NSMaxRange(endRange) error:error];
|
if (extensionResult) {
|
[decodeResult putMetadata:kResultMetadataTypeUPCEANExtension value:extensionResult.text];
|
[decodeResult putAllMetadata:[extensionResult resultMetadata]];
|
[decodeResult addResultPoints:[extensionResult resultPoints]];
|
extensionLength = (int)[extensionResult.text length];
|
}
|
|
ZXIntArray *allowedExtensions = hints == nil ? nil : hints.allowedEANExtensions;
|
if (allowedExtensions != nil) {
|
BOOL valid = NO;
|
for (int i = 0; i < allowedExtensions.length; i++) {
|
if (extensionLength == allowedExtensions.array[i]) {
|
valid = YES;
|
break;
|
}
|
}
|
if (!valid) {
|
if (error) *error = ZXNotFoundErrorInstance();
|
return nil;
|
}
|
}
|
|
if (format == kBarcodeFormatEan13 || format == kBarcodeFormatUPCA) {
|
NSString *countryID = [self.eanManSupport lookupCountryIdentifier:resultString];
|
if (countryID != nil) {
|
[decodeResult putMetadata:kResultMetadataTypePossibleCountry value:countryID];
|
}
|
}
|
return decodeResult;
|
}
|
|
- (BOOL)checkChecksum:(NSString *)s error:(NSError **)error {
|
if ([[self class] checkStandardUPCEANChecksum:s]) {
|
return YES;
|
} else {
|
if (error) *error = ZXFormatErrorInstance();
|
return NO;
|
}
|
}
|
|
+ (BOOL)checkStandardUPCEANChecksum:(NSString *)s {
|
int length = (int)[s length];
|
if (length == 0) {
|
return NO;
|
}
|
int sum = 0;
|
|
for (int i = length - 2; i >= 0; i -= 2) {
|
int digit = (int)[s characterAtIndex:i] - (int)'0';
|
if (digit < 0 || digit > 9) {
|
return NO;
|
}
|
sum += digit;
|
}
|
|
sum *= 3;
|
|
for (int i = length - 1; i >= 0; i -= 2) {
|
int digit = (int)[s characterAtIndex:i] - (int)'0';
|
if (digit < 0 || digit > 9) {
|
return NO;
|
}
|
sum += digit;
|
}
|
|
return sum % 10 == 0;
|
}
|
|
- (NSRange)decodeEnd:(ZXBitArray *)row endStart:(int)endStart error:(NSError **)error {
|
return [[self class] findGuardPattern:row
|
rowOffset:endStart
|
whiteFirst:NO
|
pattern:ZX_UPC_EAN_START_END_PATTERN
|
patternLen:ZX_UPC_EAN_START_END_PATTERN_LEN
|
error:error];
|
}
|
|
+ (NSRange)findGuardPattern:(ZXBitArray *)row rowOffset:(int)rowOffset whiteFirst:(BOOL)whiteFirst pattern:(const int[])pattern patternLen:(int)patternLen error:(NSError **)error {
|
ZXIntArray *counters = [[ZXIntArray alloc] initWithLength:patternLen];
|
return [self findGuardPattern:row rowOffset:rowOffset whiteFirst:whiteFirst pattern:pattern patternLen:patternLen counters:counters error:error];
|
}
|
|
+ (NSRange)findGuardPattern:(ZXBitArray *)row rowOffset:(int)rowOffset whiteFirst:(BOOL)whiteFirst pattern:(const int[])pattern patternLen:(int)patternLen counters:(ZXIntArray *)counters error:(NSError **)error {
|
int patternLength = patternLen;
|
int width = row.size;
|
BOOL isWhite = whiteFirst;
|
rowOffset = whiteFirst ? [row nextUnset:rowOffset] : [row nextSet:rowOffset];
|
int counterPosition = 0;
|
int patternStart = rowOffset;
|
int32_t *array = counters.array;
|
for (int x = rowOffset; x < width; x++) {
|
if ([row get:x] ^ isWhite) {
|
array[counterPosition]++;
|
} else {
|
if (counterPosition == patternLength - 1) {
|
if ([self patternMatchVariance:counters pattern:pattern maxIndividualVariance:ZX_UPC_EAN_MAX_INDIVIDUAL_VARIANCE] < ZX_UPC_EAN_MAX_AVG_VARIANCE) {
|
return NSMakeRange(patternStart, x - patternStart);
|
}
|
patternStart += array[0] + array[1];
|
|
for (int y = 2; y < patternLength; y++) {
|
array[y - 2] = array[y];
|
}
|
|
array[patternLength - 2] = 0;
|
array[patternLength - 1] = 0;
|
counterPosition--;
|
} else {
|
counterPosition++;
|
}
|
array[counterPosition] = 1;
|
isWhite = !isWhite;
|
}
|
}
|
|
if (error) *error = ZXNotFoundErrorInstance();
|
return NSMakeRange(NSNotFound, 0);
|
}
|
|
/**
|
* Attempts to decode a single UPC/EAN-encoded digit.
|
*/
|
+ (int)decodeDigit:(ZXBitArray *)row counters:(ZXIntArray *)counters rowOffset:(int)rowOffset patternType:(ZX_UPC_EAN_PATTERNS)patternType error:(NSError **)error {
|
if (![self recordPattern:row start:rowOffset counters:counters]) {
|
if (error) *error = ZXNotFoundErrorInstance();
|
return -1;
|
}
|
float bestVariance = ZX_UPC_EAN_MAX_AVG_VARIANCE;
|
int bestMatch = -1;
|
int max = 0;
|
switch (patternType) {
|
case ZX_UPC_EAN_PATTERNS_L_PATTERNS:
|
max = ZX_UPC_EAN_L_PATTERNS_LEN;
|
for (int i = 0; i < max; i++) {
|
int pattern[counters.length];
|
for (int j = 0; j < counters.length; j++){
|
pattern[j] = ZX_UPC_EAN_L_PATTERNS[i][j];
|
}
|
|
float variance = [self patternMatchVariance:counters pattern:pattern maxIndividualVariance:ZX_UPC_EAN_MAX_INDIVIDUAL_VARIANCE];
|
if (variance < bestVariance) {
|
bestVariance = variance;
|
bestMatch = i;
|
}
|
}
|
break;
|
case ZX_UPC_EAN_PATTERNS_L_AND_G_PATTERNS:
|
max = ZX_UPC_EAN_L_AND_G_PATTERNS_LEN;
|
for (int i = 0; i < max; i++) {
|
int pattern[counters.length];
|
for (int j = 0; j< counters.length; j++){
|
pattern[j] = ZX_UPC_EAN_L_AND_G_PATTERNS[i][j];
|
}
|
|
float variance = [self patternMatchVariance:counters pattern:pattern maxIndividualVariance:ZX_UPC_EAN_MAX_INDIVIDUAL_VARIANCE];
|
if (variance < bestVariance) {
|
bestVariance = variance;
|
bestMatch = i;
|
}
|
}
|
break;
|
default:
|
break;
|
}
|
|
if (bestMatch >= 0) {
|
return bestMatch;
|
} else {
|
if (error) *error = ZXNotFoundErrorInstance();
|
return -1;
|
}
|
}
|
|
- (ZXBarcodeFormat)barcodeFormat {
|
@throw [NSException exceptionWithName:NSInternalInconsistencyException
|
reason:[NSString stringWithFormat:@"You must override %@ in a subclass", NSStringFromSelector(_cmd)]
|
userInfo:nil];
|
}
|
|
- (int)decodeMiddle:(ZXBitArray *)row startRange:(NSRange)startRange result:(NSMutableString *)result error:(NSError **)error {
|
@throw [NSException exceptionWithName:NSInternalInconsistencyException
|
reason:[NSString stringWithFormat:@"You must override %@ in a subclass", NSStringFromSelector(_cmd)]
|
userInfo:nil];
|
}
|
|
@end
|