Implementation
static Future<IDCardInfo> extractInfoFromImage(InputImage image) async {
final textRecognizer = TextRecognizer(script: TextRecognitionScript.latin);
final RecognizedText recognizedText = await textRecognizer.processImage(
image,
);
String? firstName, lastName, dob, idNumber, middleName;
String? fullName;
final lines = <String>[];
// List of lines to skip if encountered as candidates
List<String> skipWords = [
"federal republic of nigeria",
"national identity management system",
"national identification number slip",
"national identification number (nins)",
"surname",
"first name",
"middle name",
"gender",
"address",
"nin",
];
bool isValidSurname(String candidate) {
if (candidate.isEmpty) return false;
String c = candidate.toLowerCase();
if (skipWords.contains(c)) return false;
// Nigerian surnames are often all uppercase and one word
if (!RegExp(r'^[A-Z]+[0-9]*$').hasMatch(candidate)) return false;
if (candidate.length < 2) return false;
return true;
}
// Flatten all lines for easier next-line lookup
for (var block in recognizedText.blocks) {
for (var line in block.lines) {
lines.add(line.text.trim());
}
}
// // Debug: Print all OCR lines for troubleshooting
// for (var l in lines) {
// print('[OCR LINE] ' + l + " ${lines.length}");
// }
// --- CARD TYPE DETECTION ---
String cardType = 'unknown';
if (lines.any(
(l) =>
l.toUpperCase().contains(
'INDEPENDENT NATIONAL ELECTORAL COMMISSION',
) ||
l.toUpperCase().contains('VOTER'),
)) {
cardType = 'voter';
} else if (lines.any(
(l) =>
l.toUpperCase().contains('PASSPORT / PASSEPORT') ||
l.toUpperCase().contains('PASSPORT NO') ||
l.toUpperCase().contains('PASSPORT NO.') ||
l.toUpperCase().contains('PASSPORT NUMBER'),
)) {
cardType = 'national';
} else if (lines.any((l) => l.contains('DIGITAL NIN SLIP'))) {
cardType = 'digitalninslip';
} else if (lines.any((l) => l.contains('National ldentification Number'))) {
cardType = 'ninslip';
} else if (lines.any(
(l) =>
l.toUpperCase().contains('NATIONAL IDENTITY MANAGEMENT') ||
l.toUpperCase().contains('NIN'),
)) {
cardType = 'nin';
} else if (lines.any(
(l) =>
l.toUpperCase().contains('DRIVER') ||
l.toUpperCase().contains('LICENCE') ||
l.toUpperCase().contains('L/NO'),
)) {
cardType = 'driver';
} else if (lines.any(
(l) =>
l.toUpperCase().contains('NATIONAL IDENTITY CARD') ||
l.toUpperCase().contains('NIMC'),
)) {
cardType = 'nimc';
}
print('[CARD TYPE] $cardType');
void extractVoter() {
// VOTER'S CARD LOGIC
// ID Number (VIN)
for (final line in lines) {
final upper = line.toUpperCase();
if (upper.contains('VIN')) {
final vinMatch = RegExp(r'VIN\s*([A-Z0-9 ]+)').firstMatch(upper);
if (vinMatch != null) {
final vinNumber = vinMatch
.group(1)!
.replaceAll(RegExp(r'[^A-Z0-9]'), '');
if (vinNumber.length >= 16) {
idNumber = vinNumber;
break;
}
}
}
}
// Name
const nonNameKeywords = ['DELIM', 'STATE', 'LGA', 'OSUN', 'IREWOLE'];
for (final line in lines) {
final upper = line.toUpperCase().trim();
final parts = upper.split(RegExp(r'\s+'));
if (parts.length == 3 &&
RegExp(r'^[A-Z ]+$').hasMatch(upper) &&
!nonNameKeywords.any((kw) => upper.contains(kw)) &&
!upper.contains('OCCUPATION')) {
lastName = parts[0].trim();
firstName = parts[1].trim();
middleName = parts[2].trim();
fullName = line.trim();
break;
}
}
// DOB
for (final line in lines) {
if (line.toUpperCase().contains('DATE OF BIRTH')) {
// Try to find date on this line or next line
String dobLine = line;
int idx = lines.indexOf(line);
if (!RegExp(r'\d').hasMatch(dobLine) && idx + 1 < lines.length) {
dobLine = lines[idx + 1];
}
// Match dd MMM yyyy, dd-mm-yyyy, dd/mm/yyyy, dd-mm-yy, etc.
final dobRegex = RegExp(
r'(\d{2})[ /-]([A-Z]{3}|\d{2})[ /-](\d{2,4})',
caseSensitive: false,
);
final match = dobRegex.firstMatch(dobLine.toUpperCase());
if (match != null) {
String day = match.group(1)!;
String month = match.group(2)!;
String year = match.group(3)!;
// Convert month name to number if needed
final months = {
'JAN': '01',
'FEB': '02',
'MAR': '03',
'APR': '04',
'MAY': '05',
'JUN': '06',
'JUL': '07',
'AUG': '08',
'SEP': '09',
'OCT': '10',
'NOV': '11',
'DEC': '12',
};
if (months.containsKey(month)) {
month = months[month]!;
}
dob = '$day-$month-$year';
break;
}
} else if (RegExp(r'\d{2}[-/]\d{2}[-/]\d{4}').hasMatch(line.trim())) {
// If the line itself is a date
dob = RegExp(
r'\d{2}[-/]\d{2}[-/]\d{4}',
).firstMatch(line.trim())!.group(0);
break;
}
}
}
void extractNIN() {
// NIN SLIP LOGIC
// ID Number
for (final line in lines) {
final text = line.toUpperCase();
if (text.startsWith('NIN')) {
final parts = line.split(':');
String candidate =
(parts.length > 1) ? parts[1].replaceAll(RegExp(r'\D'), '') : '';
if (candidate.isEmpty) {
final nextIdx = lines.indexOf(line) + 1;
if (nextIdx < lines.length) {
candidate = lines[nextIdx].replaceAll(RegExp(r'\D'), '').trim();
}
}
if (candidate.isNotEmpty) {
idNumber = candidate;
break;
}
}
}
if (idNumber == null) {
for (int i = 0; i < lines.length - 1; i++) {
final line1Raw = lines[i];
var line2Raw = lines[i + 1];
if (line2Raw.length > 4) {
line2Raw = line2Raw.substring(4);
} else {
line2Raw = '';
}
if (RegExp(r'^[0-9 ]+$').hasMatch(line1Raw) &&
RegExp(r'^[0-9 ]+$').hasMatch(line2Raw)) {
final combined = (line1Raw + line2Raw).replaceAll(' ', '');
if (combined.length >= 16) {
idNumber = combined;
break;
}
}
}
String digitsOnly = lines.join(' ').replaceAll(RegExp(r'[^0-9]'), ' ');
final idCandidates =
digitsOnly.split(' ').where((s) => s.length >= 10).toList();
idCandidates.sort((a, b) => b.length.compareTo(a.length));
if (idCandidates.isNotEmpty) {
idNumber = idCandidates.first;
}
}
// Name
for (final line in lines) {
final upper = line.toUpperCase();
if (upper.startsWith('SURNAME')) {
lastName = line.split(' ').last.trim();
} else if (upper.startsWith('FIRST NAME')) {
firstName = line.split(' ').last.trim();
} else if (upper.startsWith('MIDDLE NAME')) {
middleName = line.split(' ').last.trim();
}
}
// DOB
final dobRegex = RegExp(
r'(\d{2})[ /-]([A-Z]{3})[ /-](\d{2,4})|(\d{2})[ /-](\d{2})[ /-](\d{2,4})',
);
for (final line in lines) {
final match = dobRegex.firstMatch(line.toUpperCase());
if (match != null) {
if (match.group(2) != null) {
final day = match.group(1);
final monStr = match.group(2);
final year = match.group(3);
final months = {
'JAN': '01',
'FEB': '02',
'MAR': '03',
'APR': '04',
'MAY': '05',
'JUN': '06',
'JUL': '07',
'AUG': '08',
'SEP': '09',
'OCT': '10',
'NOV': '11',
'DEC': '12',
};
final mon = months[monStr] ?? monStr;
dob = '$day-$mon-$year';
} else if (match.group(4) != null &&
match.group(5) != null &&
match.group(6) != null) {
dob = '${match.group(4)}-${match.group(5)}-${match.group(6)}';
}
break;
}
}
}
void extractDriverLicense() {
// DRIVER'S LICENSE LOGIC
// ID Number
for (final line in lines) {
final text = line.toUpperCase();
if (text.contains('L/NO') || text.startsWith('LNO')) {
final match = RegExp(r'[A-Z0-9]{6,}').firstMatch(line);
if (match != null) {
idNumber = match.group(0);
break;
}
}
}
// Name (try comma line or labeled fields)
for (final line in lines) {
final upper = line.toUpperCase();
if (RegExp(r'^[A-Z ,]+$').hasMatch(upper) && upper.contains(',')) {
final parts = upper.split(',');
if (parts.length > 1) {
lastName = parts[0].trim();
final firstNames = parts[1].trim().split(' ');
if (firstNames.isNotEmpty) {
firstName = firstNames[0].trim();
}
if (firstNames.length > 1) {
middleName = firstNames[1].trim();
}
}
} else if (upper.startsWith('SURNAME')) {
lastName = line.split(' ').last.trim();
} else if (upper.startsWith('FIRST NAME')) {
firstName = line.split(' ').last.trim();
} else if (upper.startsWith('MIDDLE NAME')) {
middleName = line.split(' ').last.trim();
}
}
// DOB
for (int i = 0; i < lines.length; i++) {
final upper = lines[i].toUpperCase();
if (upper.contains('DOB') ||
upper.contains('D OF B') ||
upper.contains('D OF 8')) {
// Search this line and the next two lines for a date
for (int j = 0; j <= 2 && i + j < lines.length; j++) {
final dateMatch = RegExp(
r'(\d{2})[-/](\d{2})[-/](\d{2,4})',
).firstMatch(lines[i + j]);
if (dateMatch != null) {
dob = dateMatch.group(0);
break;
}
}
if (dob != null) break;
}
// Also, if a line itself is just a date, pick it up
final directDateMatch = RegExp(
r'^\d{2}[-/]\d{2}[-/]\d{2,4}$',
).firstMatch(lines[i].trim());
if (directDateMatch != null) {
dob = directDateMatch.group(0);
break;
}
}
}
void extractnational() {
String? tempSurname, tempFirstName, tempMiddleName, tempDob, tempIdNumber;
for (int i = 0; i < lines.length; i++) {
final upper = lines[i].toUpperCase().trim();
// Surname
if ((upper.contains('SURNAME') && !upper.contains('GIVEN')) ||
upper.contains('SURNAME / NOM')) {
if (i + 1 < lines.length) tempSurname = lines[i + 3].trim();
}
// Given Names
else if (upper.contains('GIVEN NAMES') ||
upper.contains('GIVEN NAMES / PRÉNOMS') ||
upper.contains('PRÉNOMS') ||
upper.contains('Glven Names/ Prénoms')) {
if (i + 1 < lines.length) {
var names = lines[i + 1].trim().split(RegExp(r'\s+'));
if (names.isNotEmpty) tempFirstName = names[0];
if (names.length > 1) tempMiddleName = names.sublist(1).join(' ');
}
}
// Date of Birth
else if (upper.contains('DATE OF BIRTH') ||
upper.contains('DATE DE NAISSANCE') ||
upper.contains('DATE OF BIRTH /DATE DE NAISSANCE')) {
if (i + 1 < lines.length) tempDob = lines[i + 1].trim();
}
// Passport No.
else if (upper.contains('PASSPART NO.') ||
upper.contains('N PASSEPORT') ||
upper.contains('PASSPART NO./N PASSEPORT')) {
print('PASSPORT NO');
print(lines[i]);
print(lines[i + 1]);
if (i + 1 < lines.length) tempIdNumber = lines[i + 1].trim();
}
}
if (tempSurname != null) lastName = tempSurname;
if (tempFirstName != null) firstName = tempFirstName;
if (tempMiddleName != null) middleName = tempMiddleName;
if (tempDob != null) {
// Clean up and normalize DOB string for national ID/passport
String dobRaw =
tempDob
.toUpperCase()
.replaceAll('É', 'E')
.replaceAll('/', ' ')
.replaceAll(RegExp(r'\s+'), ' ')
.trim();
// Map for both English and French abbreviations
final months = {
'JAN': '01',
'FEB': '02',
'MAR': '03',
'APR': '04',
'MAY': '05',
'JUN': '06',
'JUL': '07',
'AUG': '08',
'SEP': '09',
'OCT': '10',
'NOV': '11',
'DEC': '12',
'JANV': '01',
'FEV': '02',
'AVR': '04',
'MAI': '05',
'JUI': '06',
'JUIL': '07',
'AOUT': '08',
};
// Match e.g. 12 DEC 96 or 12 DEC 1996
final dobRegex = RegExp(r'(\d{1,2})\s+([A-Z]{3,5})\s+(\d{2,4})');
final match = dobRegex.firstMatch(dobRaw);
if (match != null) {
String day = match.group(1)!.padLeft(2, '0');
String monthStr = match.group(2)!;
String year = match.group(3)!;
monthStr = months[monthStr] ?? monthStr;
if (year.length == 4) year = year.substring(2);
dob = '$day/$monthStr/$year';
} else {
dob = tempDob;
}
}
if (tempIdNumber != null) idNumber = tempIdNumber;
}
void extractnimc() {
// NIMC card number extraction with duplicate group handling
List<String> digitLines =
lines
.where((l) => RegExp(r'^[0-9 ]{6,}$').hasMatch(l.trim()))
.toList();
if (digitLines.length >= 2) {
var firstLine = digitLines[0].replaceAll(' ', '');
var secondLine = digitLines[1].replaceAll(' ', '');
var firstGroups = digitLines[0].trim().split(' ');
var lastGroup = firstGroups.isNotEmpty ? firstGroups.last : '';
if (lastGroup.isNotEmpty &&
digitLines[1].trim().startsWith(lastGroup)) {
// Remove the duplicate group from the start of second line
var dedupedSecond =
digitLines[1].trim().substring(lastGroup.length).trim();
idNumber = (digitLines[0] + ' ' + dedupedSecond).replaceAll(' ', '');
} else {
idNumber = (digitLines[0] + digitLines[1]).replaceAll(' ', '');
}
}
// Name extraction for NIMC: always use the value after the label
String? tempSurname, tempFirstName, tempMiddleName;
for (int i = 0; i < lines.length; i++) {
final upper = lines[i].toUpperCase().trim();
if (upper == 'SURNAME' && i + 1 < lines.length) {
tempSurname = lines[i + 1].trim();
} else if (upper == 'FIRST NAME' && i + 1 < lines.length) {
tempFirstName = lines[i + 1].trim();
} else if (upper == 'MIDDLE NAME' && i + 1 < lines.length) {
tempMiddleName = lines[i + 1].trim();
}
}
if (tempSurname != null) lastName = tempSurname;
if (tempFirstName != null) firstName = tempFirstName;
if (tempMiddleName != null) middleName = tempMiddleName;
// DOB
final dobRegex = RegExp(
r'(\d{2})[ /-]([A-Z]{3})[ /-](\d{2,4})|(\d{2})[ /-](\d{2})[ /-](\d{2,4})',
);
for (final line in lines) {
final match = dobRegex.firstMatch(line.toUpperCase());
if (match != null) {
if (match.group(2) != null) {
final day = match.group(1);
final monStr = match.group(2);
final year = match.group(3);
final months = {
'JAN': '01',
'FEB': '02',
'MAR': '03',
'APR': '04',
'MAY': '05',
'JUN': '06',
'JUL': '07',
'AUG': '08',
'SEP': '09',
'OCT': '10',
'NOV': '11',
'DEC': '12',
};
final mon = months[monStr] ?? monStr;
dob = '$day-$mon-$year';
} else if (match.group(4) != null &&
match.group(5) != null &&
match.group(6) != null) {
dob = '${match.group(4)}-${match.group(5)}-${match.group(6)}';
}
break;
}
}
}
void extractNINslip() {
String? tempSurname, tempFirstName, tempMiddleName, tempDob, tempIdNumber;
// DOB
final dobRegex = RegExp(
r'(\d{2})[ /-]([A-Z]{3})[ /-](\d{2,4})|(\d{2})[ /-](\d{2})[ /-](\d{2,4})',
);
for (int i = 0; i < lines.length; i++) {
final upper = lines[i].toUpperCase().trim();
final match = dobRegex.firstMatch(upper);
// Surname
if ((upper.contains('SURNAME') && !upper.contains('GIVEN')) ||
upper.contains('SURNAME / NOM')) {
if (i + 1 < lines.length) tempSurname = lines[i + 3].trim();
}
// Given Names
else if (upper.contains('GIVEN NAMES') ||
upper.contains('GIVEN NAMES / PRÉNOMS') ||
upper.contains('PRÉNOMS') ||
upper.contains('Glven Names/ Prénoms')) {
if (i + 1 < lines.length) {
var names = lines[i + 1].trim().split(RegExp(r'\s+'));
if (names.isNotEmpty) tempFirstName = names[0];
if (names.length > 1) tempMiddleName = names.sublist(1).join(' ');
}
}
// Date of Birth
else if (match != null) {
if (match.group(2) != null) {
final day = match.group(1);
final monStr = match.group(2);
final year = match.group(3);
final months = {
'JAN': '01',
'FEB': '02',
'MAR': '03',
'APR': '04',
'MAY': '05',
'JUN': '06',
'JUL': '07',
'AUG': '08',
'SEP': '09',
'OCT': '10',
'NOV': '11',
'DEC': '12',
};
final mon = months[monStr] ?? monStr;
dob = '$day-$mon-$year';
} else if (match.group(4) != null &&
match.group(5) != null &&
match.group(6) != null) {
dob = '${match.group(4)}-${match.group(5)}-${match.group(6)}';
}
}
// Passport No.
else if (upper.contains('NGA')) {
print('PASSPORT NO');
print(lines[i]);
print(lines[i + 1]);
if (i + 1 < lines.length) tempIdNumber = lines[i + 1].trim();
}
}
if (tempSurname != null) lastName = tempSurname;
if (tempFirstName != null) firstName = tempFirstName;
if (tempMiddleName != null) middleName = tempMiddleName;
if (tempIdNumber != null) idNumber = tempIdNumber;
}
void extractDigitalNINslip() {
String? tempSurname, tempFirstName, tempMiddleName, tempDob, tempIdNumber;
// DOB
final dobRegex = RegExp(
r'(\d{2})[ /-]([A-Z]{3})[ /-](\d{2,4})|(\d{2})[ /-](\d{2})[ /-](\d{2,4})',
);
for (int i = 0; i < lines.length; i++) {
final upper = lines[i].toUpperCase().trim();
final match = dobRegex.firstMatch(upper);
// Surname
if ((upper.contains('SURNAME') && !upper.contains('GIVEN')) ||
upper.contains('SURNAME / NOM')) {
if (i + 1 < lines.length) tempSurname = lines[i + 1].trim();
}
// Given Names
else if (upper.contains('GIVEN NAMES') ||
upper.contains('GIVEN NAMES / PRÉNOMS') ||
upper.contains('PRÉNOMS') ||
upper.contains('Glven Names/ Prénoms')) {
if (i + 1 < lines.length) {
var names = lines[i + 1].trim().split(RegExp(r'\s+'));
if (names.isNotEmpty) tempFirstName = names[0];
if (names.length > 1) tempMiddleName = names.sublist(1).join(' ');
}
}
// Date of Birth
else if (match != null) {
if (match.group(2) != null) {
final day = match.group(1);
final monStr = match.group(2);
final year = match.group(3);
final months = {
'JAN': '01',
'FEB': '02',
'MAR': '03',
'APR': '04',
'MAY': '05',
'JUN': '06',
'JUL': '07',
'AUG': '08',
'SEP': '09',
'OCT': '10',
'NOV': '11',
'DEC': '12',
};
final mon = months[monStr] ?? monStr;
dob = '$day-$mon-$year';
} else if (match.group(4) != null &&
match.group(5) != null &&
match.group(6) != null) {
dob = '${match.group(4)}-${match.group(5)}-${match.group(6)}';
}
}
// Passport No.
else if (upper.contains('NGA')) {
if (i + 4 < lines.length) tempIdNumber = lines[i + 4].trim();
}
}
if (tempSurname != null) lastName = tempSurname;
if (tempFirstName != null) firstName = tempFirstName;
if (tempMiddleName != null) middleName = tempMiddleName;
if (tempIdNumber != null) idNumber = tempIdNumber;
}
void extractunknown() {
// GENERIC FALLBACK LOGIC (try to extract what we can)
// Try to extract DOB
final dobRegex = RegExp(
r'(\d{2})[ /-]([A-Z]{3})[ /-](\d{2,4})|(\d{2})[ /-](\d{2})[ /-](\d{2,4})',
);
for (final line in lines) {
final match = dobRegex.firstMatch(line.toUpperCase());
if (match != null) {
if (match.group(2) != null) {
final day = match.group(1);
final monStr = match.group(2);
final year = match.group(3);
final months = {
'JAN': '01',
'FEB': '02',
'MAR': '03',
'APR': '04',
'MAY': '05',
'JUN': '06',
'JUL': '07',
'AUG': '08',
'SEP': '09',
'OCT': '10',
'NOV': '11',
'DEC': '12',
};
final mon = months[monStr] ?? monStr;
dob = '$day-$mon-$year';
} else if (match.group(4) != null &&
match.group(5) != null &&
match.group(6) != null) {
dob = '${match.group(4)}-${match.group(5)}-${match.group(6)}';
}
break;
}
}
// Try to extract ID number (longest digit/letter sequence)
String idText = lines.join(' ');
final idMatch = RegExp(
r'[A-Z0-9]{10,}',
).firstMatch(idText.replaceAll(' ', ''));
if (idMatch != null) {
idNumber = idMatch.group(0);
}
// Try to extract name (first all-uppercase 2-3 word line)
for (final line in lines) {
final upper = line.toUpperCase().trim();
final parts = upper.split(RegExp(r'\s+'));
if ((parts.length == 2 || parts.length == 3) &&
RegExp(r'^[A-Z ]+$').hasMatch(upper)) {
lastName = parts[0].trim();
if (parts.length > 1) firstName = parts[1].trim();
if (parts.length > 2) middleName = parts[2].trim();
fullName = line.trim();
break;
}
}
}
// --- CARD-SPECIFIC EXTRACTION ---
switch (cardType) {
case 'voter':
extractVoter();
break;
case 'national':
extractnational();
break;
case 'nin':
extractNIN();
break;
case 'driver':
extractDriverLicense();
break;
case 'nimc':
extractnimc();
break;
case 'ninslip':
extractNINslip();
break;
case 'digitalninslip':
extractDigitalNINslip();
break;
default:
extractunknown();
break;
}
return IDCardInfo(
firstName: firstName,
lastName: lastName,
middleName: middleName,
dateOfBirth: dob,
idNumber: idNumber,
);
}
