flutter_fast_exif_reader #

A blazing-fast, universal EXIF & MakerNote reader for Flutter with zero disk re-reads, powered by native C++17 FFI.

Designed for high-throughput photo pipelines, face clustering engines, gallery viewers, and batch scanners where extracting metadata from thousands of photos must take < 0.1ms per file.

🌟 Supported Platforms #

🚀 Key Features #

• ⚡ Ultra-Fast (< 0.1ms per file): Direct in-memory C++ pointer operations with 0 bytes written to disk.
• 📷 Multi-Brand RAW & Image Format Support:
  • Canon: .CR3 (ISOBMFF multi-block CMT1–CMT4), .CR2
  • Nikon: .NEF, .NRW (Type 3 MakerNotes, Shutter Count, Lens Data)
  • Sony: .ARW, .SR2
  • Olympus / OM System: .ORF (IIRO / IIRS headers)
  • Fujifilm: .RAF (Embedded container & Film Simulation modes)
  • Panasonic / Lumix: .RW2 (IIU\0 headers)
  • Leica / Adobe / Ricoh / Pentax: .DNG, .PEF
  • Standard: .JPG, .JPEG, .JFIF
• 🏷️ Deep Vendor MakerNotes Extraction:
  • Canon: Shooting mode, LensModel, CameraSettings, ShotInfo
  • Nikon: Total Shutter Count (MakerNote TotalShutterReleases), ISO settings, Lens Data
  • Sony: Sony Model ID, Creative Style, DRO, Long Exposure NR
  • Fujifilm: Film Simulation, Dynamic Range, Film Mode
  • Olympus & Panasonic: Equipment, Quality, Macro, Firmware
• 📍 GPS Geolocation Telemetry: Latitude, Longitude, Altitude, TimeStamp.
• 🔄 Dual Dart API:
  • Strongly-typed FastExifData with parsed getters.
  • 1:1 exact drop-in replacement for package:exif (readExifFromBytes, IfdTag, Ratio).
• 🛠️ C++ Photo Pipeline Interface: Direct fast_exif::Reader::extract and fast_exif::Reader::sniffFormat for native C++ pipelines.

📦 Getting Started #

Add flutter_fast_exif_reader to your pubspec.yaml:

dependencies:
  flutter_fast_exif_reader: ^0.1.0

📱 Android Setup (GPS & Media Location Permissions) #

Starting in Android 10 (API 29) and reinforced in Android 11–14, Android OS Scoped Storage automatically redacts GPS geolocation metadata from image streams (substituting 0 deg 0' 0.0000" for coordinates) unless the application declares and requests the ACCESS_MEDIA_LOCATION permission.

1. Declare Permissions in AndroidManifest.xml #

Add the following to your android/app/src/main/AndroidManifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- Required for unredacted GPS EXIF metadata access on Android 10+ (API 29..36) -->
    <uses-permission android:name="android.permission.ACCESS_MEDIA_LOCATION" />
    <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="32" />

    <application ...>
        ...
    </application>
</manifest>

2. Request Runtime Permission #

Before picking or opening photos on Android, request the permission using permission_handler:

import 'dart:io';
import 'package:permission_handler/permission_handler.dart';

Future<void> requestMediaLocationPermission() async {
  if (Platform.isAndroid) {
    await [
      Permission.photos,
      Permission.storage,
      Permission.accessMediaLocation,
    ].request();
  }
}

💡 Usage #

1. Modern Strongly-Typed API #

import 'dart:typed_data';
import 'package:flutter_fast_exif_reader/flutter_fast_exif_reader.dart';

void parsePhoto(Uint8List imageBytes) {
  final FastExifData? exif = FlutterFastExifReader.readFromBytes(imageBytes);

  if (exif != null) {
    print('Camera: ${exif.make} ${exif.model}');
    print('Lens: ${exif.lensModel}');
    print('Settings: ${exif.fNumberString}, ${exif.exposureTimeString}, ${exif.isoString}');
    print('GPS: ${exif.latitude}, ${exif.longitude}');
    print('Process time: ${exif.processTimeMs.toStringAsFixed(2)} ms');
  }
}

2. 1:1 package:exif Drop-In Replacement #

Migrate legacy code by simply updating the import statement with zero code changes:

import 'package:flutter_fast_exif_reader/flutter_fast_exif_reader.dart';

void readLegacyExif(List<int> bytes) async {
  final Map<String, IfdTag> tags = await readExifFromBytes(bytes);

  print('Make: ${tags['Image Make']}');
  print('Orientation: ${tags['Image Orientation']}');
  print('Shutter: ${tags['EXIF ExposureTime']}');
  print('Date: ${tags['EXIF DateTimeOriginal']}');
}

3. Native C++ Pipeline Integration #

Include fast_exif_reader.h directly in your native processing pipeline:

#include "fast_exif_reader.h"

void processBuffer(const uint8_t* bytes, size_t len) {
    fast_exif::ExifInfo info;
    if (fast_exif::Reader::extract(bytes, len, info)) {
        printf("Camera: %s %s\n", info.make.c_str(), info.model.c_str());
        printf("Shutter: %s, Aperture: %s\n", info.getShutterSpeedString().c_str(), info.getApertureString().c_str());
        printf("Total Tags: %zu\n", info.tags.size());
    }
}

📊 Benchmark #

Tested across 15 real camera RAW files (16.9MB - 85.4MB):

📄 License #

This project is licensed under the MIT License - see the LICENSE file for details.