tonytonyjan / exif Goto Github PK

View Code? Open in Web Editor NEW

149.0 4.0 20.0 493 KB

The fastest Ruby EXIF reader.

License: MIT License

Ruby 33.16% C 66.84%

ruby exif

exif's Introduction

A Ruby EXIF reader written in C.

Installation

$ gem install exif

Please make sure you have installed libexif:

$ brew install libexif             # Homebrew
$ sudo apt-get install libexif-dev # APT
$ sudo yum install libexif-devel   # CentOS

Usage

data = Exif::Data.new(IO.read('sample.jpg'))   # load from string
data = Exif::Data.new("Exif\x00\x00II...")     # load raw exif data
data = Exif::Data.new(File.open('sample.jpg')) # load from file
data.model         # => "NIKON D600"
data.image_width   # => 4000
data.gps_longitude # => [(121/1), (76869/2500), (0/1)]
data.date_time     # => "2013:12:08 21:14:11"

# get all entries in an IFD
data[:ifd0]             # => {image_width: 4000, image_length: 2670, ...}
data[:ifd1]             # => {x_resolution: (72/1), y_resolution: (72/1), ...}
data[:exif]             # => exposure_time: (1/125), fnumber: (8/1)}
data[:gps]              # => {gps_version_id: [2, 2, 0, 0], gps_latitude_ref: "N", ...}
data[:interoperability] # => {...}
data.to_h               # => {:ifd0 => {...}, :ifd1 => {...}, :exif => {...}}
data.ifds == data.to_h  # => true

ifd0 takes precedence over ifd1, since ifd0 and ifd1 share the same domain of tags, sometimes the same tag can be both used inside them, in this case, calling top-level API like Exif::Data#image_width will return the value of ifd0.

Typecasting

Tag Type	Ruby Class
ASCII	String
BYTE	Integer
DOUBLE	Flat
FLOAT	Float
LONG	Integer
RATIONAL	Rational
SHORT	Integer
UNDEFINED	String

How fast?

It's hundreds of times faster than mini_exiftool or exiftool and several times faster than exifr.

There are similar excellent gems like exifr, mini_exiftool and exiftool built in pure Ruby while this one is a C extension.

If you are using JRuby you might want to give exifr, exiftool or mini_exiftool a look, the latter two are commandline wrappers for ExifTool by Phil Harvey and support many file formats. The exiftool gem can process multiple files at once while mini_exiftool can modify or copy EXIF data.

Benchmark

You can find all benchmark files in /benchmark:

Read a single tag from 100 files.

$ ruby benchmark/load_file.rb
Rehearsal ---------------------------------------------------------
mini_exiftool (2.9.0)   0.240000   0.110000  22.830000 ( 23.275885)
exiftool (1.2.0)        0.480000   0.130000  22.870000 ( 23.311755)
exifr (1.3.2)           0.120000   0.010000   0.130000 (  0.139821)
exif (49b6835)          0.020000   0.000000   0.020000 (  0.019927)
----------------------------------------------- total: 45.850000sec

                            user     system      total        real
mini_exiftool (2.9.0)   0.240000   0.120000  22.830000 ( 23.267355)
exiftool (1.2.0)        0.490000   0.130000  23.190000 ( 23.678799)
exifr (1.3.2)           0.120000   0.010000   0.130000 (  0.134572)
exif (49b6835)          0.020000   0.000000   0.020000 (  0.018419)
-----------------------------------------
1263 times faster than mini_exiftool (2.9.0)
1286 times faster than exiftool (1.2.0)
7 times faster than exifr (1.3.2)

Read many tags from the same file 1000 times.

$ ruby benchmark/read_tag.rb
Rehearsal ---------------------------------------------------------
mini_exiftool (2.9.0)   0.390000   0.000000   0.390000 (  0.404067)
exiftool (1.2.0)        0.030000   0.000000   0.030000 (  0.027073)
exifr (1.3.2)           1.220000   0.020000   1.240000 (  1.268672)
exif (49b6835)          0.010000   0.000000   0.010000 (  0.006862)
------------------------------------------------ total: 1.670000sec

                            user     system      total        real
mini_exiftool (2.9.0)   0.410000   0.010000   0.420000 (  0.412627)
exiftool (1.2.0)        0.030000   0.000000   0.030000 (  0.028518)
exifr (1.3.2)           1.180000   0.010000   1.190000 (  1.203806)
exif (49b6835)          0.010000   0.000000   0.010000 (  0.006925)
-----------------------------------------
60 times faster than mini_exiftool (2.9.0)
4 times faster than exiftool (1.2.0)
174 times faster than exifr (1.3.2)

Contribution

Please follow AngularJS git commit message conventions.

TODO

Create, update and delete tags.

exif's People

Contributors

Stargazers

Watchers

Forkers

rajraj wellington1993 arissetyawan tonpham35 aupajo kaiser34 waffleau felixbuenemann kamiiyu sirscriptalot folkscode rafadc jackzones kysnm renchap bradkrane msp-greg laurieliyang

exif's Issues

Support parsing exif from string

It would be great if Exif::Data.new could support parsing raw exif data from a string, eg.

data = Exif::Data.new("Exif\x00\x00MM\x00...")

This would make it easy to work with exif data extracted by another tool, eg. from TIFF images.

The current code allows reading an entires JPEG file as a string, it should work if it would check if the first 6 bytes of the string are Exif\x00\x00 and then treat the string as raw exif data.

"\xCD" from ASCII-8BIT to UTF-8

While trying to use exif in a Rails app (utf-8 by default).

Incorrectly reporting orientation EXIF data

I have a JPG image taken on a mobile device which added an Orientation EXIF tag since the image is rotated 90º counterclockwise.

Preview.app on Mac correctly identifies the orientation:

As does exif:

$ exif 'wrong-rotation.jpg' | grep Orientation
Orientation         |Right-top

And EXIFR:

image_data = EXIFR::JPEG.new('wrong-rotation.jpg')
image_data.orientation  # => #<EXIFR::TIFF::Orientation:RightTop(6)>

However this library returns "unrotated":

image_data = Exif::Data.new('wrong-rotation.jpg')
image_data.orientation  # => 0

Doesn't work with Panasonic Raw files (.cw2)

I think this gem would be great for me because of the speed advantage over mini_exiftool, but I get "RuntimeError: File not readable or no EXIF data in file."

mini_exiftool works as does exiftool from the command line. Obviously something is screening out the Raw files. I couldn't find any extension screening (which I might have been able to hack), but otherwise I haven't a clue.

HEIC Support?

I'm trying to read HEIC files from Apple devices but the lib returns a NullExif. I assume this probably is at the fault of libexif rather then this gem but want to see if you have a work-around or know of a way to fix this?

image_width and image_size don't work

data.image_width and data.image_length always return null. Other parameters such as "make" are there. I know my files have this information because exiftool can read it with the $imagesize tag

Divide by zero error

Hi @tonytonyjan, you helped me with an issue to do with orientation in this issue. I've opted to try to upgrade to 2.0.0 as my C is a bit too rusty to contribute code directly. :)

Unfortunately I've run into a divide by zero error in 2.0.0. I can extract using the CLI tool. Unfortunately I can't attach one of the images giving me trouble as I don't own them, but I've scrubbed some EXIF data which will hopefully give you something.

To produce, I'm just doing:

Exif::Data.new(IO.read('image.jpeg'))

And the CLI output (I've removed sensitive info):

Image Description   |MY_IMAGE.JPG
Manufacturer        |DJI
Model               |123456
Orientation         |Top-left
X-Resolution        |72
Y-Resolution        |72
Resolution Unit     |Inch
Software            |v01.01.01
Date and Time       |2017:01:01 12:00:00
YCbCr Positioning   |Centered
XP Comment          |Type=N, Mode=P, DE=None
XP Keywords         |v01.01.01;1.1.6;v1.0.0
Compression         |JPEG compression
X-Resolution        |72
Y-Resolution        |72
Resolution Unit     |Inch
Exposure Time       |1/80 sec.
F-Number            |f/4.0
Exposure Program    |Normal program
ISO Speed Ratings   |100
Exif Version        |Exif Version 2.3
Date and Time (Origi|2017:05:22 12:31:11
Date and Time (Digit|2017:05:22 12:31:11
Components Configura|- Cr Cb Y
Compressed Bits per |3.2441677
Shutter Speed       |6.32 EV (1/79 sec.)
Aperture            |4.00 EV (f/4.0)
Exposure Bias       |0.00 EV
Maximum Aperture Val|2.97 EV (f/2.8)
Subject Distance    |0.0 m
Metering Mode       |Average
Light Source        |Cloudy weather
Flash               |No flash function
Focal Length        |8.8 mm
Maker Note          |506 bytes undefined data
FlashPixVersion     |Unknown FlashPix Version
Color Space         |sRGB
Pixel X Dimension   |5472
Pixel Y Dimension   |3648
Exposure Index      |0/0
File Source         |DSC
Scene Type          |Directly photographed
Custom Rendered     |Normal process
Exposure Mode       |Auto exposure
White Balance       |Manual white balance
Digital Zoom Ratio  |0/0
Focal Length in 35mm|24
Scene Capture Type  |Standard
Gain Control        |Normal
Contrast            |Normal
Saturation          |Normal
Sharpness           |Normal
Subject Distance Ran|Unknown
GPS Tag Version     |2.3.0.0
North or South Latit|S
Latitude            |30, 59, 30.5000
East or West Longitu|E
Longitude           |140, 10, 45.5000
Altitude Reference  |Sea level
Altitude            |10
Interoperability Ind|R98
Interoperability Ver|0100

Please let me know if there's anything else I can do to help debug, happy to try branches or whatever else is useful.

Can't reference error classes from Exif module

Hey there,

I'm trying to reference Exif::Error is a rescue block:

      begin
        return Exif::Data.new(File.new(file_path, 'r'))
      rescue Exif::Error => e
        puts e
        return nil
      end

It's telling me Error isn't defined, and when I inspect the constants on Exif, only Data and Version appear.

I'm using v2.0.1.

I noticed the error classes are being set in exif.c and being used in data.c. My guess is this is some kind of variable issue. Possibly that they aren't shared across files properly? Could be wrong though.

Thanks in advance for taking a look!

New warning in Ruby 3.2.0

With the latest (3.2.0 as of this writing) version of Ruby, the gem yields a warning when instantiating a new object.

Given the following code:

require 'exif'

# Instantiates an Exif::Data object from tempfile
data = Exif::Data.new(File.open(file))

# Returns EXIF data in hash format, if present
if data.to_h.key?(:gps) && data.to_h.key?(:exif)
  puts data.to_h
else
  logger.info 'Skipping image analysis because no Exif or GPS information exists'
end

Ruby 3.2.0 prints out the following on stderr:

warning: undefining the allocator of T_DATA class Exif::Data for line 4 (the Exif::Data.new(...) bit).

The same code yielded no warnings on Ruby 2.7.5.

A similar issue discovered and fixed in another project: https://github.com/vmg/redcarpet/pull/721/files#diff-94e6d4cf98d0a12f376b9c3fb158dbc2ada0c98d2d230d356d7b7fd467a80619R179

gemspec missing required_ruby_version

Not sure what versions are supported, CI uses 2.7 and later?

spec.required_ruby_version = Gem::Requirement.new(">= 2.7")

Windows CI should work, would you like a PR?

Get raw EXIF string from parsed data

I have the following scenario:

Upload an image file to my server
Extract metadata (including EXIF)
Extract some fields from the EXIF and save them to database columns
Push the file to Amazon S3 for storage and serving and delete it from my server

The problem is that if I want to extract more fields from the EXIF at a later date I have to download my file back from S3 and pass it to this gem, which can be costly as I have many images.

What I would like to do is to get the raw EXIF string when first extracting the metadata and save it to my database and then use this gem to extract new fields by passing the string to it.

Version 2.2.2 can not be build with "old" libexif versions

The new tags added in 26f9bac require a libexif 0.6.23 or newer.
This version is quite recent and not included in, for example, Debian and Ubuntu:

275.9 exif_entry_to_ivar.c:462:8: error: ‘EXIF_TAG_IMAGE_DEPTH’ undeclared (first use
275.9 in this function); did you mean ‘EXIF_TAG_IMAGE_LENGTH’?
275.9   462 |   case EXIF_TAG_IMAGE_DEPTH:
275.9       |        ^~~~~~~~~~~~~~~~~~~~
275.9       |        EXIF_TAG_IMAGE_LENGTH

This gem should check for either the libexif version, or (probably better) for the existence of the symbol.

Unable to install on Windows ...

Ruby rookie here trying to install this native gem on Win10 x64. Obtained libexif from here:
http://www.ridgesolutions.ie/index.php/2015/03/13/libexif-binaries-for-windows-and-visual-studio/libexif-win32-0-6-21/
and extracted into root & devkit folders.

Unable to get past============================
C:\Users\kart\GitHub\ruby225 (master)
λ gem install exif --verbose
HEAD https://api.rubygems.org/api/v1/dependencies
200 OK
GET https://api.rubygems.org/api/v1/dependencies?gems=exif
200 OK
Temporarily enhancing PATH to include DevKit...
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/.gitignore
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/.rspec
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/.travis.yml
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/Gemfile
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/LICENSE.txt
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/README.md
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/Rakefile
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/benchmark/benchmark.rb
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/exif.gemspec
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/ext/exif/data.c
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/ext/exif/data.h
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/ext/exif/exif.c
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/ext/exif/exif.h
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/ext/exif/extconf.rb
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/lib/exif.rb
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/lib/exif/version.rb
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/spec/exif_spec.rb
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/spec/sample.jpg
C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1/spec/spec_helper.rb
Building native extensions. This could take a while...
C:/Users/kart/GitHub/ruby225/bin/ruby.exe -r ./siteconf20160917-7516-k4yib7.rb extconf.rb
checking for main() in -lexif... no
checking for libexif/exif-data.h... no
creating Makefile
make "DESTDIR=" clean
make "DESTDIR="
generating exif-x64-mingw32.def
compiling data.c
data.c:1:31: fatal error: libexif/exif-data.h: No such file or directory
compilation terminated.
make: *** [data.o] Error 1
ERROR: Error installing exif:
ERROR: Failed to build gem native extension.

Building has failed. See above output for more information on the failure.

make failed, exit code 2

Gem files will remain installed in C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/gems/exif-1.0.1 for inspection.

Results logged to C:/Users/kart/GitHub/ruby225/lib/ruby/gems/2.2.0/extensions/x64-mingw32/2.2.0/exif-1.0.1/gem_make.out

Would love to use this faster gem if it can work with Windows. Thanks!

complete `#test_double` and `#test_float` in `test/test_exif.rb`

symbol not found in flat namespace '_exif_data_free'

I was able to successfully install with:

C_INCLUDE_PATH=$(brew --prefix libexif)/include gem install exif

but when I try to import and use the library I get this error:

irb(main):001:0> require 'exif'
<internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:85:in `require': dlopen(/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/gems/3.2.0/gems/exif-2.2.4/lib/exif/exif.bundle, 0x0009): symbol not found in flat namespace '_exif_data_free' - /Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/gems/3.2.0/gems/exif-2.2.4/lib/exif/exif.bundle (LoadError)
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
	from /Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/gems/3.2.0/gems/exif-2.2.4/lib/exif.rb:4:in `<top (required)>'
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:159:in `require'
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:159:in `rescue in require'
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:39:in `require'
	from (irb):1:in `<main>'
	from /Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/gems/3.2.0/gems/irb-1.7.0/exe/irb:9:in `<top (required)>'
	from /Users/cjavilla/.asdf/installs/ruby/3.2.2/bin/irb:25:in `load'
	from /Users/cjavilla/.asdf/installs/ruby/3.2.2/bin/irb:25:in `<main>'
<internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:85:in `require': cannot load such file -- exif (LoadError)
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
	from (irb):1:in `<main>'
	from /Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/gems/3.2.0/gems/irb-1.7.0/exe/irb:9:in `<top (required)>'
	from /Users/cjavilla/.asdf/installs/ruby/3.2.2/bin/irb:25:in `load'
	from /Users/cjavilla/.asdf/installs/ruby/3.2.2/bin/irb:25:in `<main>'

I'm using Apple silicon locally (Apple M2 Max)

I also tried cloning this repo and running the load_file benchmark:

ruby load_file.rb
<internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require': cannot load such file -- exif/exif (LoadError)
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
	from /Users/cjavilla/repos/exif/lib/exif.rb:4:in `<top (required)>'
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
	from /Users/cjavilla/repos/exif/benchmark/env.rb:10:in `<top (required)>'
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
	from <internal:/Users/cjavilla/.asdf/installs/ruby/3.2.2/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
	from load_file.rb:3:in `<main>'

Any ideas?

Error while Installing gem in Linux

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

/usr/local/bin/ruby extconf.rb
checking for main() in -lexif... no
checking for libexif/exif-data.h... no
creating Makefile

make "DESTDIR=" clean

make "DESTDIR="
compiling exif.c
In file included from exif.c:2:0:
data.h:4:31: fatal error: libexif/exif-data.h: No such file or directory

include <libexif/exif-data.h>

^
compilation terminated.
make: *** [exif.o] Error 1

make failed, exit code 2

Exif::NotReadble error misspelled

I'm not sure what you want to do about this one, but I got tripped up while writing an exception handler – correct spelling should be Exif::NotReadable. Unfortunately, you can't change this without breaking anyone's existing explicit rescues for this error, so I'm not sure it's a good idea to change.

Interpreting GPS coordinates

I updated to 2.2.0 from 1.0.1 and the GPS coordinates are presented at:

@gps_latitude=[(40/1), (48/1), (541/10)]
@gps_latitude_ref="N"
@gps_longitude=[(96/1), (42/1), (1679/50)]
@gps_longitude_ref="W"

in 2.2.0. How am I supposed to interpret these values? Sorry if this is a dumb question.

Support reading from String

Just wondering if you have any plans to implement the reading from string functionality?

Error installation on Mac Capital 10.11

I install exif and libexif successfully already. but still error with gem exif 1.0.1

brew install libexif
==> Downloading https://homebrew.bintray.com/bottles/libexif-0.6.21.el_capitan.bottle.1.tar.gz
Already downloaded: /Library/Caches/Homebrew/libexif-0.6.21.el_capitan.bottle.1.tar.gz
==> Pouring libexif-0.6.21.el_capitan.bottle.1.tar.gz
🍺  /usr/local/Cellar/libexif/0.6.21: 29 files, 864K

brew install exif
==> Downloading https://downloads.sourceforge.net/project/libexif/exif/0.6.21/exif-0.6.21.tar.gz
Already downloaded: /Library/Caches/Homebrew/exif-0.6.21.tar.gz
==> ./configure --prefix=/usr/local/Cellar/exif/0.6.21 --disable-silent-rules --disable-nls
==> make install
🍺  /usr/local/Cellar/exif/0.6.21: 8 files, 112K, built in 9 seconds

gem install exif -v '1.0.1'

Building native extensions.  This could take a while...
ERROR:  Error installing exif:
    ERROR: Failed to build gem native extension.

    /Users/thaichorseng/.rvm/rubies/ruby-2.1.5/bin/ruby -r ./siteconf20151218-8895-1342xh5.rb extconf.rb
checking for main() in -lexif... no
checking for libexif/exif-data.h... no
creating Makefile

make "DESTDIR=" clean

make "DESTDIR="
compiling data.c
data.c:1:10: fatal error: 'libexif/exif-data.h' file not found
#include <libexif/exif-data.h>
         ^
1 error generated.
make: *** [data.o] Error 1

make failed, exit code 2

Gem files will remain installed in /Users/thaichorseng/.rvm/gems/ruby-2.1.5@yoolk_engines/gems/exif-1.0.1 for inspection.
Results logged to /Users/thaichorseng/.rvm/gems/ruby-2.1.5@yoolk_engines/extensions/x86_64-darwin-14/2.1.0/exif-1.0.1/gem_make.out

How to use Liquid to get the EXIF data using your exif tool?

@tonytonyjan How could we have a .rb plugin for Jekyll to include the EXIF data using your exif tool?

Here is something analogous for another tool called exiftag: https://github.com/benib/jekyll-exiftag/blob/master/lib/jekyll-exiftag.rb

Since it does not support PNG however, I am interested in yours! 👍

Check for existence of EXIF data?

Hi there,

Great gem - thanks for all the hard work.

Was wondering: unless I missed it, I didn't see a way to check a file or string for the presence of EXIF data before then accessing the EXIF data itself.

So if I have an image file where I don't know if EXIF data exists or not, it seems like the best way to verify is to check if the Exif::NotReadable error is returned. Is that correct / expected?

Incorrectly reporting time zone

The program reports the current computer timezone:

I have a photo taken in GMT-4 timezone, my computer currently in GMT+8 timezone.

Code:

Exif::Data.new('IMG_7368.jpg').date_time

Output:

=> 2017-06-02 12:56:26 +0800

Should be:

=> 2017-06-02 12:56:26 -0400

Passing Tempfile from Rack to Exif::Data.new raises an error

If I have an upload coming from Rack:

> file
#<Tempfile:/var/folders/r4/rd0m9j997h19dm1nz9_fg2540000gn/T/RackMultipart20171019-54278-1v4nvvt.jpg>

If I try to parse it with Exif::Data.new, I get the following error:

> Exif::Data.new(file)
TypeError: wrong argument type Tempfile (expected String or IO)

Ruby 2.7.2 crash