gr_camera_detector

A Dart package that detects whether a photo was taken with a Ricoh GR series camera.

It identifies GR cameras by analyzing EXIF metadata and filename patterns. Since it does not use dart:io, it works on all platforms including web, mobile, and desktop.

Features

📷 EXIF-based detection — Reliable identification via Make/Model metadata
📄 Filename pattern detection — Matches GR-specific filename patterns (R0######.JPG)
🌐 Multi-platform — No dart:io dependency, supports all platforms including web
✅ All models supported — From GR DIGITAL to GR IV Monochrome

Supported Models

Series	Models
GR DIGITAL	GR DIGITAL, II, III, IV
GR	GR, GR II
GR III	GR III, GR IIIx, GR III HDF, GR IIIx HDF
GR IV	GR IV, GR IV HDF, GR IV Monochrome

Getting started

dependencies:
    gr_camera_detector: ^0.1.0

Usage

Detect from image bytes (all platforms)

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

final detector = GrCameraDetector();

// Read EXIF from image bytes to detect GR camera
final Uint8List imageBytes = ...; // Image byte data
final result = await detector.detectFromBytes(imageBytes);

if (result.isGrCamera) {
  print('GR camera photo! Model: ${result.model?.displayName}');
  print('Confirmed: ${result.isConfirmed}');
}

Detect from filename

final result = detector.detectFromFilename('R0001234.JPG');

if (result.isGrCamera) {
  // Filename-based detection is an estimate, so isConfirmed == false
  print('Likely a GR camera photo (filename-based)');
}

Combined detection (bytes + filename)

final result = await detector.detectFromBytes(
  imageBytes,
  filename: 'R0001234.JPG',
);

// When both EXIF and filename match, method == DetectionMethod.both
if (result.method == DetectionMethod.both) {
  print('Both EXIF and filename confirmed');
}

Model information

final model = result.model;
if (model != null) {
  print('Model: ${model.displayName}');
  print('HDF filter: ${model.hasHdf}');
  print('Monochrome: ${model.isMonochrome}');
}

Flutter web usage

import 'package:gr_camera_detector/gr_camera_detector.dart';

// Use byte data from a file picked via file picker
final bytes = await pickedFile.readAsBytes();
final result = await GrCameraDetector().detectFromBytes(
  bytes,
  filename: pickedFile.name,
);

Detection Methods

Method	Accuracy	`isConfirmed`	Description
`DetectionMethod.exif`	High	✅ `true`	EXIF metadata verified
`DetectionMethod.filename`	Low	❌ `false`	Filename pattern estimate
`DetectionMethod.both`	Highest	✅ `true`	Both EXIF and filename matched
`DetectionMethod.none`	—	❌ `false`	Not detected

Additional information

Filename detection is for reference only, as other cameras may use similar patterns.
This package will be updated when new GR models are released.
For bug reports or feature requests, please visit GitHub Issues.