Range Error is reported when ReadExifFromBytes read an image file with Exif data having fieldOffset larger than file size or byte array size. The error comes from setPositioinSync in file_interface.dart. There is no bound checking in the function. This does not cause problem using ReadExifFromFile. It may be because file.setPositionSync(position) is more robust in file_interface_io.dart's setPositionSync.

I was wondering why the library is GPL and not something more compatible with commercial apps like Apache-2

Hey,
I'm trying to get from images the latitude and longitude coordinates from images.

I succeed to implement something, but apperntly it's not working all the time:

 Map<String, double> _convertToLatLng(List lat, String latRef, List long, String longRef) {
    try {
      if (lat == null || latRef == null || long == null || longRef == null) return {};

      double latitude;
      double longitude;

      if (latRef == 'N') 
        latitude = _convertToDegree(int.tryParse(lat[0].toString()), int.tryParse(lat[1].toString()), lat[2].toString());
      else 
        latitude = 0 - _convertToDegree(int.tryParse(lat[0].toString()), int.tryParse(lat[1].toString()), lat[2].toString());

      if (longRef == 'E') 
        longitude = _convertToDegree(int.tryParse(long[0].toString()), int.tryParse(long[1].toString()), long[2].toString());
      else 
        longitude = 0 - _convertToDegree(int.tryParse(long[0].toString()), int.tryParse(long[1].toString()), long[2].toString());

      return { 'latitude': latitude, 'longitude': longitude };
    } catch(ex) {
      print('_convertToLatLng ex: $ex');
      return {};
    }
  }

  double _convertToDegree(int deg, int min, String secondsFormula) {
    final List<String> strSeconds = secondsFormula.split('/');
    final double seconds = int.tryParse(strSeconds[0]) / int.tryParse(strSeconds[1]);

    return deg + (min / 60) + (seconds / 3600);
  }

Do I miss something ?

I'm running my app on mobile platforms, but also on web. I get an empty map when using readExifFromBytes and it seems like it is not supported on web

Judging by the issues and the latest answers in 2021, I have a question: does anyone continue to work on this project or not?

hello @bigflood how do you extract elif given a file http/s url

on flutter web i get "Error: Unsupported operation: _Namespace"
any ideas as to why ?

Image Orientation {Image ImageWidth: 3264, Image ImageLength: 2448, Image ExifOffset: 62, Image Orientation: 0, EXIF LightSource: Unknown} - picture rotated 90 degrees

Hey there, thanks a lot for this package!! I was wondering if it could be possible to implement the extraction of IPTC data as well.. i was trying to add hex-values to you list of tags, but it didnt work out (by now).

`0x0207: 'Edit Status',
// CONTENT #############################
0x0269: 'Headline',
0x0278: 'Description',
0x027a: 'Description Writer/Editor',
0x020f: 'Category',
0x0214: 'Other Categories',

// CONTACT #############################
0x0250: 'Creator',
0x0255: 'Job-Title',
0x025a: 'City',
0x025f: 'Province/State',
0x0264: 'PLZ',
0x0265: 'Country/Primary Location Name',

// IMAGE ########################################
0x0237: 'Date Created',
0x023c: 'Time Created',

/* 0x025a: 'City',
0x025f: 'State',
0x0265: 'Country/Primary Location Name',
0x0264: 'Country/Primary Location Code',*/

// STATUS ###########################
0x020a: 'Urgency',
0x0228: 'Special Instructions',
0x022a: 'Action Advised',

// COPYRIGHT ############################
0x0274: 'Copyright Notice',

// Contact Info
0x0276: 'Contact',

// Media
0x0114: 'File Format',
0x0116: 'File Format Version',
0x0282: 'Image Type',
0x0283: 'Image Orientation',

// Image Preferences
0x024b: 'Object Cycle',

// Event and Location

/* 0x025a: 'City',
0x025f: 'Province/State',
0x0264: 'Country/Primary Location Code',
0x0265: 'Country/Primary Location Name',*/

// Locations Taken and Shown
0x021a: 'Content Location Code',
0x021b: 'Content Location Name',

// Licensing
0x02ba: 'Short Document ID',
0x02bb: 'Unique Document ID',
0x02bc: 'Owner ID',`

It'd be great to use this library to write exif data to a file.

Future<Map<String, IfdTag>> readExifFromBytes(List<int> bytes,
    {String? stopTag,
    bool details = true,
    bool strict = false,
    bool debug = false,
    bool truncateTags = true}) async {
  return readExifFromFileReader(FileReader.fromBytes(bytes),
          stopTag: stopTag,
          details: details,
          strict: strict,
          debug: debug,
          truncateTags: truncateTags)
      .tags;
}

Since readExifFromFileReader is a sync function readExifFromBytes should be too.
It's currently make us believe that there is some async process running

"type 'FieldType' is not a subtype of type 'int'"
#0 new PrintFormat. (package:sprintf/src/sprintf_impl.dart:14:41)
#1 PrintFormat.call (package:sprintf/src/sprintf_impl.dart:88:39)
#2 ExifHeader.processTag (package:exif/src/exifheader.dart:120:38)
#3 ExifHeader.dumpIfd (package:exif/src/exifheader.dart:91:9)
#4 DecodeMakerNote._dumpIfd2 (package:exif/src/exif_decode_makernote.dart:294:16)
#5 DecodeMakerNote._decodeApple (package:exif/src/exif_decode_makernote.dart:166:5)
#6 DecodeMakerNote._decodeMakerNote (package:exif/src/exif_decode_makernote.dart:76:9)
#7 DecodeMakerNote.decode (package:exif/src/exif_decode_makernote.dart:38:5)
#8 readExifFromFileReader (package:exif/src/read_exif.dart:104:54)
#9 readExifFromBytes (package:exif/src/read_exif.dart:26:10)

package:sprintf/src/sprintf_impl.dart

For few days, I am not getting any latitude and longitude data from picked image from Gallery. Though its contained the geo latlng, but after checking in exif it's showing [0/0, 0/0, 0/0] as value.

"GPS GPSLatitude" -> [0/0, 0/0, 0/0]
"GPS GPSLongitude" -> [0/0, 0/0, 0/0]

I receive a No exif information exception for this picture:
https://user-images.githubusercontent.com/16626063/117620390-c08f4380-b170-11eb-8630-ff300692695a.jpg

with this tool (http://exif.regex.info/exif.cgi), data are read correctly.

Do you think you can investigate ?
I tried but i'm a bit lost in the middle of the code/specs

Thanks

JFIF

JFIF Version	1.01
Resolution	300 pixels/inch
File — basic information derived from the file.

File Type	JPEG
File Type Extension	jpg
MIME Type	image/jpeg
Encoding Process	Progressive DCT, Huffman coding
Bits Per Sample	8
Color Components	3
File Size	72 kB
Image Size	853 × 480
Y Cb Cr Sub Sampling	YCbCr4:2:0 (2 2)
Composite
This block of data is computed based upon other items. Some of it may be wildly incorrect, especially if the image has been resized.

Megapixels	0.409

exif version 1.0
Have a look this image
If you use tool like http://exif.regex.info/exif.cgi you can see data like camera, location and son on.

But when I try to use exactly the same image with this library it shows only:

Image Orientation (Short): Horizontal (normal)
Image ExifOffset (Long): 38
ColorSpace (Short): sRGB
ExifImageWidth (Long): 640
ExifImageLength (Long): 480

Where is the rest tags? Why it doesn't parse properly all tags?

the code I use:

file.then((fileData) async {
              Map<String, IfdTag> data  = await readExifFromBytes(fileData);
              if (data == null || data.isEmpty) {
                debugPrint("No EXIF information found\n");
              return;
              }
          
              for (String key in data.keys) {
                debugPrint("$key (${data[key].tagType}): ${data[key]}");
              }
            });

PS. Sorry after more test I figure out that issue with image picker library and iOS. On Android everything works fine

what is the best way to extract the exif data, say to double or date format?

Hi, Thank you for making the package.
I noticed that readExifFromBytes causes RangeError for some images.
I am not sure which image cause that. But the image which caused the error was the image cropped by the smart phone application.

E/flutter (23641): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter (23641): RangeError (start): Invalid value: Only valid value is 0: 8
E/flutter (23641): #0 RangeError.checkValidRange (dart:core/errors.dart:327:7)
E/flutter (23641): #1 List.sublist (dart:core/runtime/libgrowable_array.dart:81:22)
E/flutter (23641): #2 make_string_uc (package:exif/src/util.dart:31:13)
E/flutter (23641): #3 ExifHeader.dump_ifd (package:exif/src/exifheader.dart:350:35)
E/flutter (23641): #4 readExifFromFileReader (package:exif/src/read_exif.dart:241:9)
E/flutter (23641): #5 readExifFromBytes (package:exif/src/read_exif.dart:22:17)

I'm interested in this lib in order to strip out exif data from jpegs, but I don't see a top-level helper to do that. Would you be interested in adding that to the API?

My particular use case is allowing users to insert images into our app, but without the exif data.

I know some exif data (e.g. rotation) affect appearance, so perhaps this API should/could be more intelligent than just stripping and instead apply relevant transforms?

Anyway, just wanted to get a feel for the idea. Happy to implement if it's desired, though probably not for a few months due to work priorities.
Thanks!

Hi, I am using Flutter with the camera plugin.
It seems that the library always reports orientation 6 which means landscape left which is incorrect.

I use the following code to determine the orientation from EXIF:

Future<int> getEXIFOrientationCorrection(List<int> image) async {

  int rotationCorrection = 0;
  Map<String, IfdTag> exif = await readExifFromBytes(image);

  if (exif == null || exif.isEmpty) {
    print("No EXIF information found");
  } else {
    print("Found EXIF information");
    // http://sylvana.net/jpegcrop/exif_orientation.html
    IfdTag orientation = exif["Image Orientation"];
    int orientationValue = orientation.values[0];
    // in degress
    print("orientation: ${orientation.printable}/${orientation.values[0]}");
    switch (orientationValue) {
      case 6:
        rotationCorrection = 90;
        break;
      case 3:
        rotationCorrection = 180;
        break;
      case 8:
        rotationCorrection = 270;
        break;
    }
  }
  return rotationCorrection;
}

orientation.values[0] seems to always be 6.
Tested with Iphone 7 (should have orientation=1) and Samsung Galaxy S3 mini (should have orientation=6).

However, for both phones the library reports orientation=6 which is wrong for the iPhone.
If I analyze the image with imagemagick, it reports orientation=1 which is correct for the iPhone 7:

$ identify -format '%[EXIF:Orientation]' flutter_camera_portrait.jpg
1

I took the image with the camera plugin on Iphone 7 and retrieved it from the device by printing it's base64 value to stdout. See the image here:

Version: : 3.0.0
Partial Stack trace :

errors.dart in RangeError.checkValidRange at line 338
array.dart in _List.sublist at line 197
read_exif.dart in _isTiff at line 186 within exif

Because xyz_app depends on exif 3.1.2 which depends on sprintf ^6.0.0, sprintf ^6.0.0 is required.

sprintf is already at a major version bump (7.0.0), would be nice to get this plugin also synced with that.

I checked with my image which have lat lng information

code is as exampled.

final data = await readExifFromBytes(fileBytes);

  if (data.isEmpty) {
    print("No EXIF information found");
    return;
  }

  for (final entry in data.entries) {
    print("${entry.key}: ${entry.value}");
  }

but result is

I/flutter (29756): GPS GPSDate: 2021:12:18
I/flutter (29756): GPS GPSProcessingMethod: [65, 83, 67, 73, 73, 0, 0, 0, 71, 80, 83, 0]
I/flutter (29756): GPS GPSTimeStamp: [14, 48, 34]
I/flutter (29756): GPS GPSAltitude: 13483/125
I/flutter (29756): GPS GPSAltitudeRef: 0
I/flutter (29756): GPS GPSLongitude: [127, 5, 150143/10000]
I/flutter (29756): GPS GPSLongitudeRef: E
I/flutter (29756): GPS GPSLatitude: [35, 48, 40797/1250]
I/flutter (29756): GPS GPSLatitudeRef: N
I/flutter (29756): Image ExifOffset: 212

how can I convert GPS latitude like 35, 48, 40797/1250 to gps data to search in google map?

Future<Map<String?, IfdTag>?> readExifFromBytes

I'm not sure why you would expect an IfdTag with a null key?

Future<Map<String, IfdTag>?> readExifFromBytes is what I would assume to be correct?

Hi,
I am trying to extract exif data to get the DateTimeOriginal information.
The script work very well with JPEG and Nikon NEF files.
But with Canon CR3 files, i get an empty list from the readExifFromBytes function.

Here is the script i use:

import 'dart:io';
import 'package:exif/exif.dart';
import 'package:exif_test/exif_test.dart' as exif_test;

void main(List<String> arguments) async {
  // String filename = './DSC_0700_038.JPG';
  // String filename = './DSC_1270.NEF';
  String filename = './OD2_2676.CR3';

  print("read $filename ...");

  final fileBytes = File(filename).readAsBytesSync();
  final data = await readExifFromBytes(
    fileBytes,
    // debug: true,
  );

  if (data.isEmpty) {
    print("No EXIF information found");
    return;
  }

  if (data.containsKey('JPEGThumbnail')) {
    print('File has JPEG thumbnail');
    data.remove('JPEGThumbnail');
  }
  if (data.containsKey('TIFFThumbnail')) {
    print('File has TIFF thumbnail');
    data.remove('TIFFThumbnail');
  }

  for (final entry in data.entries) {
    print("${entry.key}: ${entry.value}");
  }
}

Do I miss something? Or is there a restriction for extracting EXIF data from Canon CR3 files?

Il also try with a node.js script i wrote with the npmjs exiftools-vendored package and i can réead exif datas from CR3 file with this javascript package. So i am shure that EXC-IF datas are present in this CR3 file.

https://albums.ente.io?t=C5afhVdr#9spNGaMztMxKjL8Nu4z2t8dCRub2BAqJUgUfqUoRdCJi
https://i.redd.it/zm4nfgq29yi91.jpg

The dartexif package returns 0 exif tags while the exiftool is able to identify the correct exif data.

ExifTool Version Number         : 12.42
File Name                       : sample_image.jpg
Directory                       : .
File Size                       : 13 MB
File Modification Date/Time     : 2022:08:22 14:21:54+05:30
File Access Date/Time           : 2022:08:22 14:26:36+05:30
File Inode Change Date/Time     : 2022:08:22 14:22:33+05:30
File Permissions                : -rw-r--r--
File Type                       : JPEG
File Type Extension             : jpg
MIME Type                       : image/jpeg
JFIF Version                    : 1.01
Resolution Unit                 : None
X Resolution                    : 1
Y Resolution                    : 1
Profile CMM Type                : Linotronic
Profile Version                 : 2.1.0
Profile Class                   : Display Device Profile
Color Space Data                : RGB
Profile Connection Space        : XYZ
Profile Date Time               : 1998:02:09 06:49:00
Profile File Signature          : acsp
Primary Platform                : Microsoft Corporation
CMM Flags                       : Not Embedded, Independent
Device Manufacturer             : Hewlett-Packard
Device Model                    : sRGB
Device Attributes               : Reflective, Glossy, Positive, Color
Rendering Intent                : Media-Relative Colorimetric
Connection Space Illuminant     : 0.9642 1 0.82491
Profile Creator                 : Hewlett-Packard
Profile ID                      : 0
Profile Copyright               : Copyright (c) 1998 Hewlett-Packard Company
Profile Description             : sRGB IEC61966-2.1
Media White Point               : 0.95045 1 1.08905
Media Black Point               : 0 0 0
Red Matrix Column               : 0.43607 0.22249 0.01392
Green Matrix Column             : 0.38515 0.71687 0.09708
Blue Matrix Column              : 0.14307 0.06061 0.7141
Device Mfg Desc                 : IEC http://www.iec.ch
Device Model Desc               : IEC 61966-2.1 Default RGB colour space - sRGB
Viewing Cond Desc               : Reference Viewing Condition in IEC61966-2.1
Viewing Cond Illuminant         : 19.6445 20.3718 16.8089
Viewing Cond Surround           : 3.92889 4.07439 3.36179
Viewing Cond Illuminant Type    : D50
Luminance                       : 76.03647 80 87.12462
Measurement Observer            : CIE 1931
Measurement Backing             : 0 0 0
Measurement Geometry            : Unknown
Measurement Flare               : 0.999%
Measurement Illuminant          : D65
Technology                      : Cathode Ray Tube Display
Red Tone Reproduction Curve     : (Binary data 2060 bytes, use -b option to extract)
Green Tone Reproduction Curve   : (Binary data 2060 bytes, use -b option to extract)
Blue Tone Reproduction Curve    : (Binary data 2060 bytes, use -b option to extract)
Image Width                     : 13216
Image Height                    : 13216
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:2:0 (2 2)
Image Size                      : 13216x13216
Megapixels                      : 174.7

The current GitHub master version of exif, 1.0.3, is not published yet at pub.dev.

Please, publish it, since is a importante feature, be portable and be able use it in a Web context too.

Best regards.

exif.tools web site reports the correct lat/lon, but all I see in the data from dartexif is this:

I/flutter (25377): GPS GPSVersionID: [0, 0, 0, 0] I/flutter (25377): GPS GPSLatitudeRef: I/flutter (25377): GPS GPSLatitude: [0/0, 0/0, 0/0] I/flutter (25377): GPS GPSLongitudeRef: I/flutter (25377): GPS GPSLongitude: [0/0, 0/0, 0/0] I/flutter (25377): Image GPSInfo: 1012
I thought maybe the file had GPS info stripped out, so i transferred it from the android emulator to my windows desktop, then uploaded to exif.tools web site, and it reports the correct lat/lon.

Is there something wrong in my process?

since flutter stable 2.0.0 is there with stable null safety, it would be nice to have this package migrated as well

Hi I was wondering why readExifFromFile returns an empty object {}

Exception stack trace

StateError: Bad state: No element
  File "list.dart", line 222, in ListMixin.reduce
  File "util.dart", line 37, in makeString
  File "values_to_printable.dart", line 24, in new ValuesToPrintable.convert
  File "exifheader.dart", line 128, in ExifHeader.processTag
  File "exifheader.dart", line 91, in ExifHeader.dumpIfd
  File "exif_decode_makernote.dart", line 280, in DecodeMakerNote._dumpIfd
  File "exif_decode_makernote.dart", line 107, in DecodeMakerNote._decodeNikon
  File "exif_decode_makernote.dart", line 60, in DecodeMakerNote._decodeMakerNote
  File "exif_decode_makernote.dart", line 38, in DecodeMakerNote.decode
  File "read_exif.dart", line 104, in readExifFromFileReader
  File "read_exif.dart", line 44, in readExifFromFile

There doesn't seem to be an easy way to feed a list of bytes to this library. I only found "read from file".

Thanks!

Can not able to get LatLng co-ordinate from image using exif.

Getting 58 map items but can't able to find LatLng co-ordinates also tried with GPS as well.
final latRef = data['GPS GPSLatitudeRef']?.toString();
print("ref"+latRef.toString());
var latVal = gpsValuesToFloat(data['GPS GPSLatitude']?.values);

Bu it is giving null values from exif

Hi from what I read, how may I implement in order just to get the date and time of the exif please help for my school project thank you :D

how can i get image's size? like width and height

I have tried loading a gallery image and passed to the function

try {
      Map<String, IfdTag> data = await readExifFromBytes(
          await file.readAsBytes()); // no future, only assigns after getting?

      if (data == null || data.isEmpty) {
        print("No EXIF information found\n");
        return;
      }
...

The code is caught with the exception

failed to read exif data!
I/flutter ( 8948): whereType is not yet supported

Now is that my image issue or I am calling the function wrong entirely?

I try to get the GPS information from the image but it seems can't find anythings, what's the key should I take for get the lat/lng info?

thanks!

When I use your example in https://github.com/bigflood/exifviewer, I cannot get orientation info of the captured image with camera plugin, but the picked image have this info. This is a bug in your library or camera plugin do not write orientation info to the captured image?

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel master, v1.7.5-pre.21, on Microsoft Windows [Version 10.0.17763.557], locale en-US)

[√] Android toolchain - develop for Android devices (Android SDK version 29.0.0)
[X] Visual Studio - develop for Windows
    X Visual Studio not installed; this is necessary for Windows development.
      Download at https://visualstudio.microsoft.com/downloads/.
[√] Android Studio (version 3.4)
[√] VS Code (version 1.33.1)
[!] Connected device
    ! No devices available

! Doctor found issues in 2 categories.