Include all the new files in the gem

Split and refactor code + fixes

.github/workflows/test.yml

@@ -0,0 +1,45 @@
+---
+name: Tests
+on: [ push, pull_request ]
+jobs:
+  test:
+    name: Test (Ruby ${{ matrix.ruby }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby:
+          - '2.3'
+          - '2.4'
+          - '2.5'
+          - '2.6'
+          - '2.7'
+          - '3.0'
+          - '3.1'
+          - '3.2'
+          - '3.3'
+          - '3.4'
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler-cache: true
+      - run: bundle exec rake
+  test_old_ruby:
+    name: Test (Ruby ${{ matrix.ruby }})
+    runs-on: ubuntu-20.04
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby:
+          - '2.0'
+          - '2.1'
+          - '2.2'
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler-cache: true
+      - run: bundle exec rake

.gitignore

@@ -0,0 +1,3 @@
+pkg/
+Gemfile.lock
+.DS_Store

CHANGELOG

@@ -0,0 +1,48 @@
+Version 2.4.0
+
+03-Jan-2025
+
+- IMPROVED: Refactor code into multiple files
+- FIX: error rising from redirects to unknown url scheme
+- FIX: Handle tiff format with long dimensions values
+- FIX: Remove problematic dependency on base64 gem
+- IMPROVED: properties including content_length are fetched more lazily improving performance
+
+Version 2.3.1
+
+01-Apr-2024
+
+- FIX: avoid bug where a NoMethodError exception is raised on faulty images
+
+Version 2.3.0
+
+24-Dec-2023
+
+- FIX: replace test tiff that triggers Clam-AV
+- FIX: certain heif files could not be parsed
+- FEATURE: Adds animated support for png
+
+Version 2.2.7
+
+23-May-2023
+
+- FEATURE: Adds animated? support for webp and avif images
+
+Version 2.2.6
+
+16-December-2021
+
+- FEATURE: Add support for AVIF support
+
+Version 2.2.5
+
+10-August-2021
+
+- FIX: handle HEIC/HEIF rotation angle
+
+Version 2.2.4
+
+02-June-2021
+
+- FEATURE: Added support for HEIC format
+- FIX: Support SVG files that start with a BOM character

Gemfile

@@ -0,0 +1,2 @@
+source 'https://rubygems.org'
+gemspec

MIT-LICENSE

@@ -0,0 +1,20 @@
+Copyright (c) 2008-2013 Stephen Sykes
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README

@@ -1,74 +0,0 @@
-FastImage
-
-FastImage finds the size or type of an image given its uri by fetching as little as needed
-
-The problem
-
-Your app needs to find the size or type of an image.  This could be for adding width and height attributes to an image tag, for adjusting layouts or overlays to fit an image or any other of dozens of reasons.
-
-But the image is not locally stored - it's on another asset server, or in the cloud - at Amazon S3 for example.
-
-You don't want to download the entire image to your app server - it could be many tens of kilobytes, or even megabytes just to get this information.  For most image types, the size of the image is simply stored at the start of the file.  For JPEG files it's a little bit more complex, but even so you do not need to fetch most of the image to find the size.
-
-FastImage does this minimal fetch for image types GIF, JPEG, PNG and BMP.  And it doesn't rely on installing external libraries such as RMagick (which relies on ImageMagick or GraphicsMagick) or ImageScience (which relies on FreeImage).
-
-You only need supply the uri, and FastImage will do the rest.
-
-Fastimage can also read local (and other) files, and uses the open-uri library to do so.
-
-Examples
-
-  require 'fastimage'
-
-  FastImage.size("http://stephensykes.com/images/ss.com_x.gif")
-  => [266, 56]  # width, height
-  FastImage.type("http://stephensykes.com/images/pngimage")
-  => :png
-  FastImage.type("/some/local/file.gif")
-  => :gif
-
-Installation
-
-h4. Gem
-
-  sudo gem install sdsykes-fastimage -s http://gems.github.com
-
-h4. Rails
-
-Install the gem as above, and configure it in your environment.rb file as below:
-
-  ...
-  Rails::Initializer.run do |config|
-    ...
-    config.gem "sdsykes-fastimage", :lib=>"fastimage"
-    ...
-  end
-  ...
-
-Then you're off - just use FastImage.size() and FastImage.type() in your code as in the examples.
-
-Documentation
-
-"http://rdoc.info/projects/sdsykes/fastimage":http://rdoc.info/projects/sdsykes/fastimage
-
-Tests
-
-You'll need to 'sudo gem install fakeweb' to be able to run the tests.
-
-  ruby test/test.rb
-  Loaded suite test/test
-  Started
-  ...............
-  Finished in 0.059392 seconds.
-
-  15 tests, 27 assertions, 0 failures, 0 errors
-
-
-References
-* "http://pennysmalls.com/2008/08/19/find-jpeg-dimensions-fast-in-ruby/":http://pennysmalls.com/2008/08/19/find-jpeg-dimensions-fast-in-ruby/
-* "http://snippets.dzone.com/posts/show/805":http://snippets.dzone.com/posts/show/805
-* "http://www.anttikupila.com/flash/getting-jpg-dimensions-with-as3-without-loading-the-entire-file/":http://www.anttikupila.com/flash/getting-jpg-dimensions-with-as3-without-loading-the-entire-file/
-* "http://imagesize.rubyforge.org/":http://imagesize.rubyforge.org/
-
-
-(c) 2009 Stephen Sykes

README.md

@@ -0,0 +1,205 @@
+[![https://rubygems.org/gems/fastimage](https://img.shields.io/gem/dt/fastimage.svg)](https://rubygems.org/gems/fastimage)
+[![https://github.com/sdsykes/fastimage/actions/workflows/test.yml](https://github.com/sdsykes/fastimage/actions/workflows/test.yml/badge.svg?branch=master)](https://github.com/sdsykes/fastimage/actions/workflows/test.yml)
+
+# FastImage
+
+**FastImage finds the size or type of an image given its uri by fetching as little as needed**
+
+## The problem
+
+Your app needs to find the size or type of an image. This could be for adding width and height attributes to an image tag, for adjusting layouts or overlays to fit an image or any other of dozens of reasons.
+
+But the image is not locally stored - it's on another asset server, or in the cloud - at Amazon S3 for example.
+
+You don't want to download the entire image to your app server - it could be many tens of kilobytes, or even megabytes just to get this information. For most common image types (GIF, PNG, BMP etc.), the size of the image is simply stored at the start of the file. For JPEG files it's a little bit more complex, but even so you do not need to fetch much of the image to find the size.
+
+FastImage does this minimal fetch for image types GIF, JPEG, PNG, TIFF, BMP, ICO, CUR, PSD, SVG, WEBP and JXL. And it doesn't rely on installing external libraries such as RMagick (which relies on ImageMagick or GraphicsMagick) or ImageScience (which relies on FreeImage).
+
+You only need supply the uri, and FastImage will do the rest.
+
+## Features
+
+- Reads local (and other) files - anything that is not parseable as a URI will be interpreted as a filename, and - will attempt to open it with `File#open`.
+
+- Automatically reads from any object that responds to `:read` - for instance an IO object if that is passed instead of a URI.
+
+- Follows up to 4 HTTP redirects to get the image.
+
+- Obey the `http_proxy` setting in your environment to route requests via a proxy. You can also pass a `:proxy` argument if you want to specify the proxy address in the call.
+
+- Add a timeout to the request which will limit the request time by passing `:timeout => number_of_seconds`.
+
+- Returns `nil` if it encounters an error, but you can pass `:raise_on_failure => true` to get an exception.
+
+- Provides a reader for the content length header provided in HTTP. This may be useful to assess the file size of an image, but do not rely on it exclusively - it will not be present in chunked responses for instance.
+
+- Accepts additional HTTP headers. This can be used to set a user agent or referrer which some servers require. Pass an `:http_header` argument to specify headers, e.g., `:http_header => {'User-Agent' => 'Fake Browser'}`.
+
+- Gives you information about the parsed display orientation of an image with Exif data (jpeg or tiff).
+
+- Handles [Data URIs](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URLs) correctly.
+
+## Security
+
+Take care to sanitise the strings passed to FastImage; it will try to read from whatever is passed.
+
+## Examples
+
+```ruby
+require 'fastimage'
+
+FastImage.size("https://switchstep.com/images/ios.gif")
+=> [196, 283]  # width, height
+FastImage.type("http://switchstep.com/images/ss_logo.png")
+=> :png
+FastImage.type("/some/local/file.gif")
+=> :gif
+File.open("/some/local/file.gif", "r") {|io| FastImage.type(io)}
+=> :gif
+FastImage.size("http://switchstep.com/images/favicon.ico", :raise_on_failure=>true, :timeout=>0.01)
+=> raises FastImage::ImageFetchFailure
+FastImage.size("http://switchstep.com/images/favicon.ico", :raise_on_failure=>true, :timeout=>2)
+=> [16, 16]
+FastImage.size("http://switchstep.com/images/faulty.jpg", :raise_on_failure=>true)
+=> raises FastImage::SizeNotFound
+FastImage.new("http://switchstep.com/images/ss_logo.png").content_length
+=> 4679
+FastImage.size("http://switchstep.com/images/ss_logo.png", :http_header => {'User-Agent' => 'Fake Browser'})
+=> [300, 300]
+FastImage.new("http://switchstep.com/images/ExifOrientation3.jpg").orientation
+=> 3
+FastImage.size("data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==")
+=> [1, 1]
+```
+
+## Installation
+
+### Gem
+
+```sh
+gem install fastimage
+```
+
+### Bundler
+
+Add fastimage to your Gemfile.
+
+```ruby
+gem 'fastimage'
+```
+
+Then you're off - just use `FastImage.size()` and `FastImage.type()` in your code as in the examples.
+
+## Documentation
+
+http://sdsykes.github.io/fastimage/rdoc/FastImage.html
+
+## Maintainer
+
+FastImage is maintained by Stephen Sykes (sdsykes). SamSaffron also helps out from time to time (thanks!).
+
+## Benchmark
+
+It's way faster than conventional methods for most types of file when fetching over the wire. Compared here by using OpenURI which will fetch the whole file.
+
+```ruby
+require 'benchmark'
+require 'fastimage'
+require 'open-uri'
+
+uri = "http://upload.wikimedia.org/wikipedia/commons/b/b4/Mardin_1350660_1350692_33_images.jpg"
+puts Benchmark.measure {URI.open(uri, 'rb') {|fh| p FastImage.size(fh)}}
+[9545, 6623]
+  0.059088   0.067694   0.126782 (  0.808131)
+
+puts Benchmark.measure {p FastImage.size(uri)}
+[9545, 6623]
+  0.006198   0.001563   0.007761 (  0.162021)
+```
+
+The file is fetched in about 0.8 seconds in this test (the number in brackets is the total time taken), but as FastImage doesn't need to fetch the whole thing, it completes in 0.16s.
+
+You'll see similar excellent results for the other file types.
+
+```ruby
+require 'benchmark'
+require 'fastimage'
+require 'open-uri'
+
+uri = "https://upload.wikimedia.org/wikipedia/commons/a/a9/Augustine_Herrman_1670_Map_Virginia_Maryland.tiff"
+puts Benchmark.measure {URI.open(uri, 'rb') {|fh| p FastImage.size(fh)}}
+[12805, 10204]
+  1.332587   2.049915   3.382502 ( 19.925270)
+
+puts Benchmark.measure {p FastImage.size(uri)}
+[12805, 10204]
+  0.004593   0.000924   0.005517 (  0.100592)
+```
+
+Some tiff files however do not have their metadata near the start of the file.
+
+```ruby
+require 'benchmark'
+require 'fastimage'
+require 'open-uri'
+
+uri = "https://upload.wikimedia.org/wikipedia/commons/1/14/Center-Filled_LIMA.tif"
+puts Benchmark.measure {URI.open(uri, 'rb') {|fh| p FastImage.size(fh)}}
+[22841, 19404]
+  0.350304   0.321104   0.671408 (  3.053605)
+
+puts Benchmark.measure {p FastImage.size(uri)}
+[22841, 19404]
+  0.163443   0.214301   0.377744 (  2.880414)
+```
+
+Note that if you want a really fast result for this file type, [image_size](https://github.com/toy/image_size?tab=readme-ov-file#experimental-fetch-image-meta-from-http-server) might be useful as it has an optimisation for this (fetching only the needed data range).
+
+```ruby
+require 'benchmark'
+require 'image_size/uri'
+require 'fastimage'
+
+uri = "https://upload.wikimedia.org/wikipedia/commons/1/14/Center-Filled_LIMA.tif"
+puts Benchmark.measure {p ImageSize.url(uri).size }
+[22841, 19404]
+  0.008983   0.001311   0.010294 (  0.128986)
+
+puts Benchmark.measure {p FastImage.size(uri)}
+[22841, 19404]
+  0.163443   0.214301   0.377744 (  2.880414)
+```
+
+## Tests
+
+You'll need to bundle, or `gem install fakeweb` and possibly also  `gem install test-unit` to be able to run the tests.
+
+```sh
+ruby test/test.rb
+```
+
+## References
+
+- [Pennysmalls - Find jpeg dimensions fast in pure Ruby, no image library needed](http://pennysmalls.wordpress.com/2008/08/19/find-jpeg-dimensions-fast-in-pure-ruby-no-ima/)
+- [Antti Kupila - Getting JPG dimensions with AS3 without loading the entire file](https://www.anttikupila.com/archive/getting-jpg-dimensions/)
+- [imagesize gem](https://rubygems.org/gems/imagesize)
+- [EXIF Reader](https://github.com/remvee/exifr)
+
+## FastImage in other languages
+
+- [Python by bmuller](https://github.com/bmuller/fastimage)
+- [Swift by kaishin](https://github.com/kaishin/ImageScout)
+- [Go by rubenfonseca](https://github.com/rubenfonseca/fastimage)
+- [PHP by tommoor](https://github.com/tommoor/fastimage)
+- [Node.js by ShogunPanda](https://github.com/ShogunPanda/fastimage)
+- [Objective C by kylehickinson](https://github.com/kylehickinson/FastImage)
+- [Android by qstumn](https://github.com/qstumn/FastImageSize)
+- [Flutter by ky1vstar](https://github.com/ky1vstar/fastimage.dart)
+
+### Also of interest
+- [C++ by xiaozhuai](https://github.com/xiaozhuai/imageinfo)
+- [Rust by xiaozhuai](https://github.com/xiaozhuai/imageinfo-rs)
+
+## Licence
+
+MIT, see file "MIT-LICENSE"

README.textile

@@ -1,88 +0,0 @@
-h1. FastImage
-
-h4. FastImage finds the size or type of an image given its uri by fetching as little as needed
-
-h2. The problem
-
-Your app needs to find the size or type of an image.  This could be for adding width and height attributes to an image tag, for adjusting layouts or overlays to fit an image or any other of dozens of reasons.
-
-But the image is not locally stored - it's on another asset server, or in the cloud - at Amazon S3 for example.
-
-You don't want to download the entire image to your app server - it could be many tens of kilobytes, or even megabytes just to get this information.  For most image types, the size of the image is simply stored at the start of the file.  For JPEG files it's a little bit more complex, but even so you do not need to fetch most of the image to find the size.
-
-FastImage does this minimal fetch for image types GIF, JPEG, PNG and BMP.  And it doesn't rely on installing external libraries such as RMagick (which relies on ImageMagick or GraphicsMagick) or ImageScience (which relies on FreeImage).
-
-You only need supply the uri, and FastImage will do the rest.
-
-Fastimage can also read local (and other) files, and uses the open-uri library to do so.
-
-h2. Examples
-
-<pre>
-<code>
-require 'fastimage'
-
-FastImage.size("http://stephensykes.com/images/ss.com_x.gif")
-=> [266, 56]  # width, height
-FastImage.type("http://stephensykes.com/images/pngimage")
-=> :png
-FastImage.type("/some/local/file.gif")
-=> :gif
-</code>
-</pre>
-
-h2. Installation
-
-h4. Gem
-
-<pre>
-<code>
-  sudo gem install sdsykes-fastimage -s http://gems.github.com
-</code>
-</pre>
-
-h4. Rails
-
-Install the gem as above, and configure it in your environment.rb file as below:
-<pre>
-<code>
-...
-Rails::Initializer.run do |config|
-  ...
-  config.gem "sdsykes-fastimage", :lib=>"fastimage"
-  ...
-end
-...
-</code>
-</pre>
-Then you're off - just use FastImage.size() and FastImage.type() in your code as in the examples.
-
-h2. Documentation
-
-"http://rdoc.info/projects/sdsykes/fastimage":http://rdoc.info/projects/sdsykes/fastimage
-
-h2. Tests
-
-You'll need to 'sudo gem install fakeweb' to be able to run the tests.
-
-<pre>
-<code>
-ruby test/test.rb
-Loaded suite test/test
-Started
-...............
-Finished in 0.059392 seconds.
-
-15 tests, 27 assertions, 0 failures, 0 errors
-</code>
-</pre>
-
-
-h2. References
-* "http://pennysmalls.com/2008/08/19/find-jpeg-dimensions-fast-in-ruby/":http://pennysmalls.com/2008/08/19/find-jpeg-dimensions-fast-in-ruby/
-* "http://snippets.dzone.com/posts/show/805":http://snippets.dzone.com/posts/show/805
-* "http://www.anttikupila.com/flash/getting-jpg-dimensions-with-as3-without-loading-the-entire-file/":http://www.anttikupila.com/flash/getting-jpg-dimensions-with-as3-without-loading-the-entire-file/
-* "http://imagesize.rubyforge.org/":http://imagesize.rubyforge.org/
-
-
-(c) 2009 Stephen Sykes

Rakefile

@@ -1,17 +1,23 @@
-require 'rake'
+# frozen_string_literal: true
 
-begin
+require "rdoc/task"
-  require 'jeweler'
+require "rake/testtask"
-  Jeweler::Tasks.new do |s|
+require "bundler/gem_tasks"
-    s.name = "fastimage"
+
-    s.summary = "FastImage - Image info fast"
+# Generate documentation
-    s.email = "sdsykes@gmail.com"
+Rake::RDocTask.new do |rd|
-    s.homepage = "http://github.com/sdsykes/fastimage"
+  rd.main = "README.rdoc"
-    s.description = "FastImage finds the size or type of an image given its uri by fetching as little as needed."
+  rd.rdoc_files.include("*.rdoc", "lib/**/*.rb")
-    s.authors = ["Stephen Sykes"]
+  rd.rdoc_dir = "rdoc"
-    s.files = FileList["[A-Z]*", "{lib,test}/**/*"]
-  end
-rescue LoadError
-  puts "Jeweler not available. Install it with: sudo gem install technicalpickles-jeweler -s http://
-gems.github.com"
 end
+
+#require 'bundler'
+#Bundler::GemHelper.install_tasks
+
+Rake::TestTask.new do |t|
+  t.libs << "test"
+  t.test_files = FileList['test/test.rb']
+  t.verbose = true
+end
+
+task :default => :test

VERSION.yml

@@ -1,4 +0,0 @@
---- 
-:major: 1
-:minor: 2
-:patch: 1

fastimage.gemspec

@@ -1,29 +1,30 @@
-# -*- encoding: utf-8 -*-
+require_relative "lib/fastimage/version"
 
 Gem::Specification.new do |s|
   s.name = %q{fastimage}
-  s.version = "1.2.1"
+  s.version = FastImage::VERSION
 
-  s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
+  s.required_ruby_version = '>= 1.9.2'
   s.authors = ["Stephen Sykes"]
-  s.date = %q{2009-09-17}
   s.description = %q{FastImage finds the size or type of an image given its uri by fetching as little as needed.}
   s.email = %q{sdsykes@gmail.com}
-  s.extra_rdoc_files = ["README", "README.textile"]
+  s.extra_rdoc_files = [
-  s.files = ["Rakefile", "README", "README.textile", "VERSION.yml", "lib/fastimage.rb", "test/fixtures", "test/fixtures/faulty.jpg", "test/fixtures/test.bmp", "test/fixtures/test.gif", "test/fixtures/test.ico", "test/fixtures/test.jpg", "test/fixtures/test.png", "test/test.rb"]
+    "README.md"
+  ]
+  s.files = [
+    "MIT-LICENSE",
+    "README.md"
+  ] + Dir.glob("lib/**/*")
   s.homepage = %q{http://github.com/sdsykes/fastimage}
-  s.rdoc_options = ["--inline-source", "--charset=UTF-8"]
+  s.rdoc_options = ["--charset=UTF-8"]
   s.require_paths = ["lib"]
-  s.rubygems_version = %q{1.3.5}
+  s.rubygems_version = %q{1.3.6}
   s.summary = %q{FastImage - Image info fast}
+  s.add_development_dependency 'fakeweb-fi', '~> 1.3'
+  # Note rake 11 drops support for ruby 1.9.2
+  s.add_development_dependency('rake', ">= 10.5")
+  s.add_development_dependency('rdoc')
+  s.add_development_dependency('test-unit')
 
-  if s.respond_to? :specification_version then
+  s.licenses = ['MIT']
-    current_version = Gem::Specification::CURRENT_SPECIFICATION_VERSION
-    s.specification_version = 3
-
-    if Gem::Version.new(Gem::RubyGemsVersion) >= Gem::Version.new('1.2.0') then
-    else
-    end
-  else
-  end
 end

lib/fastimage.rb

@@ -1,3 +1,6 @@
+# frozen_string_literal: true
+# coding: ASCII-8BIT
+
 # FastImage finds the size or type of an image given its uri.
 # It is careful to only fetch and parse as much of the image as is needed to determine the result.
 # It does this by using a feature of Net::HTTP that yields strings from the resource being fetched
@@ -6,275 +9,65 @@
 # No external libraries such as ImageMagick are used here, this is a very lightweight solution to
 # finding image information.
 #
-# FastImage knows about GIF, JPEG, BMP and PNG files.
+# FastImage knows about GIF, JPEG, BMP, TIFF, ICO, CUR, PNG, HEIC/HEIF, AVIF, PSD, SVG, WEBP and JXL files.
 #
 # FastImage can also read files from the local filesystem by supplying the path instead of a uri.
-# In this case FastImage uses the open-uri library to read the file in chunks of 256 bytes until
+# In this case FastImage reads the file in chunks of 256 bytes until
 # it has enough. This is possibly a useful bandwidth-saving feature if the file is on a network
 # attached disk rather than truly local.
 #
+# FastImage will automatically read from any object that responds to :read - for
+# instance an IO object if that is passed instead of a URI.
+#
+# FastImage will follow up to 4 HTTP redirects to get the image.
+#
+# FastImage also provides a reader for the content length header provided in HTTP.
+# This may be useful to assess the file size of an image, but do not rely on it exclusively -
+# it will not be present in chunked responses for instance.
+#
+# FastImage accepts additional HTTP headers. This can be used to set a user agent
+# or referrer which some servers require. Pass an :http_header argument to specify headers,
+# e.g., :http_header => {'User-Agent' => 'Fake Browser'}.
+#
+# FastImage can give you information about the parsed display orientation of an image with Exif
+# data (jpeg or tiff).
+#
 # === Examples
 #   require 'fastimage'
 #
-#   FastImage.size("http://stephensykes.com/images/ss.com_x.gif")
+#   FastImage.size("https://switchstep.com/images/ios.gif")
-#   => [266, 56]
+#   => [196, 283]
-#   FastImage.type("http://stephensykes.com/images/pngimage")
+#   FastImage.type("http://switchstep.com/images/ss_logo.png")
 #   => :png
 #   FastImage.type("/some/local/file.gif")
 #   => :gif
+#   File.open("/some/local/file.gif", "r") {|io| FastImage.type(io)}
+#   => :gif
+#   FastImage.new("http://switchstep.com/images/ss_logo.png").content_length
+#   => 4679
+#   FastImage.new("http://switchstep.com/images/ExifOrientation3.jpg").orientation
+#   => 3
 #
 # === References
-# * http://snippets.dzone.com/posts/show/805
 # * http://www.anttikupila.com/flash/getting-jpg-dimensions-with-as3-without-loading-the-entire-file/
-# * http://pennysmalls.com/2008/08/19/find-jpeg-dimensions-fast-in-ruby/
+# * http://pennysmalls.wordpress.com/2008/08/19/find-jpeg-dimensions-fast-in-pure-ruby-no-ima/
-# * http://imagesize.rubyforge.org/
+# * https://rubygems.org/gems/imagesize
+# * https://github.com/remvee/exifr
 #
+
 require 'net/https'
-require 'open-uri'
+require 'delegate'
+require 'pathname'
+require 'zlib'
+require 'uri'
+require 'stringio'
 
-class FastImage
+require_relative 'fastimage/fastimage'
-  attr_reader :size, :type
+require_relative 'fastimage/version'
 
-  class FastImageException < StandardError # :nodoc:
+# see http://stackoverflow.com/questions/5208851/i/41048816#41048816
-  end
+if RUBY_VERSION < "2.2"
-  class MoreCharsNeeded < FastImageException # :nodoc:
+  module URI
-  end
+    DEFAULT_PARSER = Parser.new(:HOSTNAME => "(?:(?:[a-zA-Z\\d](?:[-\\_a-zA-Z\\d]*[a-zA-Z\\d])?)\\.)*(?:[a-zA-Z](?:[-\\_a-zA-Z\\d]*[a-zA-Z\\d])?)\\.?")
-  class UnknownImageType < FastImageException # :nodoc:
-  end
-  class ImageFetchFailure < FastImageException # :nodoc:
-  end
-  class SizeNotFound < FastImageException # :nodoc:
-  end
-
-  DefaultTimeout = 2
-  
-  LocalFileChunkSize = 256
-
-  # Returns an array containing the width and height of the image.
-  # It will return nil if the image could not be fetched, or if the image type was not recognised.
-  #
-  # By default there is a timeout of 2 seconds for opening and reading from a remote server.
-  # This can be changed by passing a :timeout => number_of_seconds in the options.
-  #
-  # If you wish FastImage to raise if it cannot size the image for any reason, then pass
-  # :raise_on_failure => true in the options.
-  #
-  # FastImage knows about GIF, JPEG, BMP and PNG files.
-  #
-  # === Example
-  #
-  #   require 'fastimage'
-  #
-  #   FastImage.size("http://stephensykes.com/images/ss.com_x.gif")
-  #   => [266, 56]
-  #   FastImage.size("http://stephensykes.com/images/pngimage")
-  #   => [16, 16]
-  #   FastImage.size("http://farm4.static.flickr.com/3023/3047236863_9dce98b836.jpg")
-  #   => [500, 375]
-  #   FastImage.size("http://www-ece.rice.edu/~wakin/images/lena512.bmp")
-  #   => [512, 512]
-  #   FastImage.size("test/fixtures/test.jpg")
-  #   => [882, 470]
-  #   FastImage.size("http://pennysmalls.com/does_not_exist")
-  #   => nil
-  #   FastImage.size("http://pennysmalls.com/does_not_exist", :raise_on_failure=>true)
-  #   => raises FastImage::ImageFetchFailure
-  #   FastImage.size("http://stephensykes.com/favicon.ico", :raise_on_failure=>true)
-  #   => raises FastImage::UnknownImageType
-  #   FastImage.size("http://stephensykes.com/favicon.ico", :raise_on_failure=>true, :timeout=>0.01)
-  #   => raises FastImage::ImageFetchFailure
-  #   FastImage.size("http://stephensykes.com/images/faulty.jpg", :raise_on_failure=>true)
-  #   => raises FastImage::SizeNotFound
-  #
-  # === Supported options
-  # [:timeout]
-  #   Overrides the default timeout of 2 seconds.  Applies both to reading from and opening the http connection.
-  # [:raise_on_failure]
-  #   If set to true causes an exception to be raised if the image size cannot be found for any reason.
-  #
-  def self.size(uri, options={})
-    new(uri, options).size
-  end
-
-  # Returns an symbol indicating the image type fetched from a uri.
-  # It will return nil if the image could not be fetched, or if the image type was not recognised.
-  #
-  # By default there is a timeout of 2 seconds for opening and reading from a remote server.
-  # This can be changed by passing a :timeout => number_of_seconds in the options.
-  #
-  # If you wish FastImage to raise if it cannot find the type of the image for any reason, then pass
-  # :raise_on_failure => true in the options.
-  #
-  # === Example
-  #
-  #   require 'fastimage'
-  #
-  #   FastImage.type("http://stephensykes.com/images/ss.com_x.gif")
-  #   => :gif
-  #   FastImage.type("http://stephensykes.com/images/pngimage")
-  #   => :png
-  #   FastImage.type("http://farm4.static.flickr.com/3023/3047236863_9dce98b836.jpg")
-  #   => :jpeg
-  #   FastImage.type("http://www-ece.rice.edu/~wakin/images/lena512.bmp")
-  #   => :bmp
-  #   FastImage.type("test/fixtures/test.jpg")
-  #   => :jpeg
-  #   FastImage.type("http://pennysmalls.com/does_not_exist")
-  #   => nil
-  #
-  # === Supported options
-  # [:timeout]
-  #   Overrides the default timeout of 2 seconds.  Applies both to reading from and opening the http connection.
-  # [:raise_on_failure]
-  #   If set to true causes an exception to be raised if the image type cannot be found for any reason.
-  #
-  def self.type(uri, options={})
-    new(uri, options.merge(:type_only=>true)).type
-  end
-
-  def initialize(uri, options={})
-    @property = options[:type_only] ? :type : :size
-    @timeout = options[:timeout] || DefaultTimeout
-    @uri = uri
-    @parsed_uri = URI.parse(uri)
-    if @parsed_uri.scheme == "http" || @parsed_uri.scheme == "https"
-      fetch_using_http
-    else
-      fetch_using_open_uri
-    end
-    raise SizeNotFound if options[:raise_on_failure] && @property == :size && !@size
-  rescue Timeout::Error, SocketError, Errno::ECONNREFUSED, Errno::EHOSTUNREACH, Errno::ECONNRESET, ImageFetchFailure
-    raise ImageFetchFailure if options[:raise_on_failure]
-  rescue Errno::ENOENT
-    raise ImageFetchFailure if options[:raise_on_failure]    
-  rescue UnknownImageType
-    raise UnknownImageType if options[:raise_on_failure]
-  end
-
-  private
-
-  def fetch_using_http
-    setup_http
-    @http.request_get(@parsed_uri.request_uri) do |res|
-      raise ImageFetchFailure unless res.is_a?(Net::HTTPSuccess)
-      res.read_body do |str|
-        break if parse_packet(str)
-      end
-    end
-  end
-
-  def setup_http
-    @http = Net::HTTP.new(@parsed_uri.host, @parsed_uri.port)
-    @http.use_ssl = (@parsed_uri.scheme == "https")
-    @http.verify_mode = OpenSSL::SSL::VERIFY_NONE
-    @http.open_timeout = @timeout
-    @http.read_timeout = @timeout
-  end
-
-  def fetch_using_open_uri
-    open(@uri) do |s|
-      while str = s.read(LocalFileChunkSize)
-        break if parse_packet(str)
-      end
-    end
-  end
-
-  # returns true once result is achieved
-  #
-  def parse_packet(str)
-    @str = (@unused_str || "") + str
-    @strpos = 0
-    begin
-      result = send("parse_#{@property}")
-      if result 
-        instance_variable_set("@#{@property}", result)
-        true
-      end
-    rescue MoreCharsNeeded
-      false
-    end
-  end
-
-  def parse_size
-    @type = parse_type unless @type
-    send("parse_size_for_#{@type}")
-  end
-
-  def get_chars(n)
-    if @strpos + n - 1 >= @str.size
-      @unused_str = @str[@strpos..-1]
-      raise MoreCharsNeeded
-    else
-      result = @str[@strpos..(@strpos + n - 1)]
-      @strpos += n
-      result
-    end
-  end
-
-  def get_byte
-    get_chars(1).unpack("C")[0]
-  end
-
-  def read_int(str)
-    size_bytes = str.unpack("CC")
-    (size_bytes[0] << 8) + size_bytes[1]
-  end
-
-  def parse_type
-    case get_chars(2)
-    when "BM"
-      :bmp
-    when "GI"
-      :gif
-    when 0xff.chr + 0xd8.chr
-      :jpeg
-    when 0x89.chr + "P"
-      :png
-    else
-      raise UnknownImageType
-    end
-  end
-
-  def parse_size_for_gif
-    get_chars(9)[4..8].unpack('SS')
-  end
-
-  def parse_size_for_png
-    get_chars(23)[14..22].unpack('NN')
-  end
-
-  def parse_size_for_jpeg
-    loop do
-      @state = case @state
-      when nil
-        get_chars(2)
-        :started
-      when :started
-        get_byte == 0xFF ? :sof : :started          
-      when :sof
-        c = get_byte
-        if (0xe0..0xef).include?(c)
-          :skipframe
-        elsif [0xC0..0xC3, 0xC5..0xC7, 0xC9..0xCB, 0xCD..0xCF].detect {|r| r.include? c}
-          :readsize
-        else
-          :skipframe
-        end
-      when :skipframe
-        @skip_chars = read_int(get_chars(2)) - 2
-        :do_skip
-      when :do_skip
-        get_chars(@skip_chars)
-        :started
-      when :readsize
-        s = get_chars(7)
-        return [read_int(s[5..6]), read_int(s[3..4])]
-      end
-    end
-  end
-
-  def parse_size_for_bmp
-    d = get_chars(27)[12..26]
-    d[0] == 40 ? d[4..-1].unpack('LL') : d[4..8].unpack('SS')
   end
 end

lib/fastimage/fastimage.rb

@@ -0,0 +1,471 @@
+require_relative 'fastimage_parsing/image_base'
+require_relative 'fastimage_parsing/stream_util'
+
+require_relative 'fastimage_parsing/avif'
+require_relative 'fastimage_parsing/bmp'
+require_relative 'fastimage_parsing/exif'
+require_relative 'fastimage_parsing/fiber_stream'
+require_relative 'fastimage_parsing/gif'
+require_relative 'fastimage_parsing/heic'
+require_relative 'fastimage_parsing/ico'
+require_relative 'fastimage_parsing/iso_bmff'
+require_relative 'fastimage_parsing/jpeg'
+require_relative 'fastimage_parsing/jxl'
+require_relative 'fastimage_parsing/jxlc'
+require_relative 'fastimage_parsing/png'
+require_relative 'fastimage_parsing/psd'
+require_relative 'fastimage_parsing/svg'
+require_relative 'fastimage_parsing/tiff'
+require_relative 'fastimage_parsing/type_parser'
+require_relative 'fastimage_parsing/webp'
+
+class FastImage
+  include FastImageParsing
+
+  attr_reader :bytes_read
+
+  class FastImageException < StandardError # :nodoc:
+  end
+  class UnknownImageType < FastImageException # :nodoc:
+  end
+  class ImageFetchFailure < FastImageException # :nodoc:
+  end
+  class SizeNotFound < FastImageException # :nodoc:
+  end
+  class CannotParseImage < FastImageException # :nodoc:
+  end
+  class BadImageURI < FastImageException # :nodoc:
+  end
+
+  DefaultTimeout = 2 unless const_defined?(:DefaultTimeout)
+
+  LocalFileChunkSize = 256 unless const_defined?(:LocalFileChunkSize)
+
+  private
+
+  Parsers = {
+    :bmp => Bmp,
+    :gif => Gif,
+    :jpeg => Jpeg,
+    :png => Png,
+    :tiff => Tiff,
+    :psd => Psd,
+    :heic => Heic,
+    :heif => Heic,
+    :webp => Webp,
+    :svg => Svg,
+    :ico => Ico,
+    :cur => Ico,
+    :jxl => Jxl,
+    :avif => Avif
+  }.freeze
+
+  public
+
+  SUPPORTED_IMAGE_TYPES = Parsers.keys.freeze
+  
+  # Returns an array containing the width and height of the image.
+  # It will return nil if the image could not be fetched, or if the image type was not recognised.
+  #
+  # By default there is a timeout of 2 seconds for opening and reading from a remote server.
+  # This can be changed by passing a :timeout => number_of_seconds in the options.
+  #
+  # If you wish FastImage to raise if it cannot size the image for any reason, then pass
+  # :raise_on_failure => true in the options.
+  #
+  # FastImage knows about GIF, JPEG, BMP, TIFF, ICO, CUR, PNG, HEIC/HEIF, AVIF, PSD, SVG, WEBP and JXL files.
+  #
+  # === Example
+  #
+  #   require 'fastimage'
+  #
+  #   FastImage.size("https://switchstep.com/images/ios.gif")
+  #   => [196, 283]
+  #   FastImage.size("http://switchstep.com/images/ss_logo.png")
+  #   => [300, 300]
+  #   FastImage.size("https://upload.wikimedia.org/wikipedia/commons/0/09/Jpeg_thumb_artifacts_test.jpg")
+  #   => [1280, 800]
+  #   FastImage.size("https://eeweb.engineering.nyu.edu/~yao/EL5123/image/lena_gray.bmp")
+  #   => [512, 512]
+  #   FastImage.size("test/fixtures/test.jpg")
+  #   => [882, 470]
+  #   FastImage.size("http://switchstep.com/does_not_exist")
+  #   => nil
+  #   FastImage.size("http://switchstep.com/does_not_exist", :raise_on_failure=>true)
+  #   => raises FastImage::ImageFetchFailure
+  #   FastImage.size("http://switchstep.com/images/favicon.ico", :raise_on_failure=>true)
+  #   => [16, 16]
+  #   FastImage.size("http://switchstep.com/foo.ics", :raise_on_failure=>true)
+  #   => raises FastImage::UnknownImageType
+  #   FastImage.size("http://switchstep.com/images/favicon.ico", :raise_on_failure=>true, :timeout=>0.01)
+  #   => raises FastImage::ImageFetchFailure
+  #   FastImage.size("http://switchstep.com/images/faulty.jpg", :raise_on_failure=>true)
+  #   => raises FastImage::SizeNotFound
+  #
+  # === Supported options
+  # [:timeout]
+  #   Overrides the default timeout of 2 seconds.  Applies both to reading from and opening the http connection.
+  # [:raise_on_failure]
+  #   If set to true causes an exception to be raised if the image size cannot be found for any reason.
+  #
+  def self.size(uri, options={})
+    new(uri, options).size
+  end
+
+  # Returns an symbol indicating the image type fetched from a uri.
+  # It will return nil if the image could not be fetched, or if the image type was not recognised.
+  #
+  # By default there is a timeout of 2 seconds for opening and reading from a remote server.
+  # This can be changed by passing a :timeout => number_of_seconds in the options.
+  #
+  # If you wish FastImage to raise if it cannot find the type of the image for any reason, then pass
+  # :raise_on_failure => true in the options.
+  #
+  # === Example
+  #
+  #   require 'fastimage'
+  #
+  #   FastImage.type("https://switchstep.com/images/ios.gif")
+  #   => :gif
+  #   FastImage.type("http://switchstep.com/images/ss_logo.png")
+  #   => :png
+  #   FastImage.type("https://upload.wikimedia.org/wikipedia/commons/0/09/Jpeg_thumb_artifacts_test.jpg")
+  #   => :jpeg
+  #   FastImage.type("https://eeweb.engineering.nyu.edu/~yao/EL5123/image/lena_gray.bmp")
+  #   => :bmp
+  #   FastImage.type("test/fixtures/test.jpg")
+  #   => :jpeg
+  #   FastImage.type("http://switchstep.com/does_not_exist")
+  #   => nil
+  #   File.open("/some/local/file.gif", "r") {|io| FastImage.type(io)}
+  #   => :gif
+  #   FastImage.type("test/fixtures/test.tiff")
+  #   => :tiff
+  #   FastImage.type("test/fixtures/test.psd")
+  #   => :psd
+  #
+  # === Supported options
+  # [:timeout]
+  #   Overrides the default timeout of 2 seconds.  Applies both to reading from and opening the http connection.
+  # [:raise_on_failure]
+  #   If set to true causes an exception to be raised if the image type cannot be found for any reason.
+  #
+  def self.type(uri, options={})
+    new(uri, options).type
+  end
+
+  # Returns a boolean value indicating the image is animated.
+  # It will return nil if the image could not be fetched, or if the image type was not recognised.
+  #
+  # By default there is a timeout of 2 seconds for opening and reading from a remote server.
+  # This can be changed by passing a :timeout => number_of_seconds in the options.
+  #
+  # If you wish FastImage to raise if it cannot find the type of the image for any reason, then pass
+  # :raise_on_failure => true in the options.
+  #
+  # === Example
+  #
+  #   require 'fastimage'
+  #
+  #   FastImage.animated?("test/fixtures/test.gif")
+  #   => false
+  #   FastImage.animated?("test/fixtures/animated.gif")
+  #   => true
+  #
+  # === Supported options
+  # [:timeout]
+  #   Overrides the default timeout of 2 seconds.  Applies both to reading from and opening the http connection.
+  # [:raise_on_failure]
+  #   If set to true causes an exception to be raised if the image type cannot be found for any reason.
+  #
+  def self.animated?(uri, options={})
+    new(uri, options).animated
+  end
+  
+  def initialize(uri, options={})
+    @uri = uri
+    @options = {
+      :timeout          => DefaultTimeout,
+      :raise_on_failure => false,
+      :proxy            => nil,
+      :http_header      => {}
+    }.merge(options)
+  end
+
+  def type
+    @property = :type
+    fetch unless defined?(@type)
+    @type
+  end
+
+  def size
+    @property = :size
+    begin
+      fetch unless defined?(@size)
+    rescue CannotParseImage
+    end
+
+    raise SizeNotFound if @options[:raise_on_failure] && !@size
+
+    @size
+  end
+
+  def orientation
+    size unless defined?(@size)
+    @orientation ||= 1 if @size
+  end
+
+  def width
+    size && @size[0]
+  end
+
+  def height
+    size && @size[1]
+  end
+
+  def animated
+    @property = :animated
+    fetch unless defined?(@animated)
+    @animated
+  end
+  
+  def content_length
+    @property = :content_length
+    fetch unless defined?(@content_length)
+    @content_length
+  end
+
+  # find an appropriate method to fetch the image according to the passed parameter
+  def fetch
+    raise BadImageURI if @uri.nil?
+
+    if @uri.respond_to?(:read)
+      fetch_using_read(@uri)
+    elsif @uri.start_with?('data:')
+      fetch_using_base64(@uri)
+    else
+      begin
+        @parsed_uri = URI.parse(@uri)
+      rescue URI::InvalidURIError
+        fetch_using_file_open
+      else
+        if @parsed_uri.scheme == "http" || @parsed_uri.scheme == "https"
+          fetch_using_http
+        else
+          fetch_using_file_open
+        end
+      end
+    end
+
+    raise SizeNotFound if @options[:raise_on_failure] && @property == :size && !@size
+
+  rescue Timeout::Error, SocketError, Errno::ECONNREFUSED, Errno::EHOSTUNREACH, Errno::ECONNRESET,
+    Errno::ENETUNREACH, ImageFetchFailure, Net::HTTPBadResponse, EOFError, Errno::ENOENT,
+    OpenSSL::SSL::SSLError
+    raise ImageFetchFailure if @options[:raise_on_failure]
+  rescue UnknownImageType, BadImageURI, CannotParseImage
+    raise if @options[:raise_on_failure]
+  
+  ensure
+    @uri.rewind if @uri.respond_to?(:rewind)
+
+  end
+
+  private
+
+  def fetch_using_http
+    @redirect_count = 0
+
+    fetch_using_http_from_parsed_uri
+  end
+
+  # Some invalid locations need escaping
+  def escaped_location(location)
+    begin
+      URI(location)
+    rescue URI::InvalidURIError
+      ::URI::DEFAULT_PARSER.escape(location)
+    else
+      location
+    end
+  end
+
+  def fetch_using_http_from_parsed_uri
+    raise ImageFetchFailure unless @parsed_uri.is_a?(URI::HTTP)
+
+    http_header = {'Accept-Encoding' => 'identity'}.merge(@options[:http_header])
+
+    setup_http
+    @http.request_get(@parsed_uri.request_uri, http_header) do |res|
+      if res.is_a?(Net::HTTPRedirection) && @redirect_count < 4
+        @redirect_count += 1
+        begin
+          location = res['Location']
+          raise ImageFetchFailure if location.nil? || location.empty?
+
+          @parsed_uri = URI.join(@parsed_uri, escaped_location(location))
+        rescue URI::InvalidURIError
+        else
+          fetch_using_http_from_parsed_uri
+          break
+        end
+      end
+
+      raise ImageFetchFailure unless res.is_a?(Net::HTTPSuccess)
+
+      @content_length = res.content_length
+      break if @property == :content_length
+
+      read_fiber = Fiber.new do
+        res.read_body do |str|
+          Fiber.yield str
+        end
+        nil
+      end
+
+      case res['content-encoding']
+      when 'deflate', 'gzip', 'x-gzip'
+        begin
+          gzip = Zlib::GzipReader.new(FiberStream.new(read_fiber))
+        rescue FiberError, Zlib::GzipFile::Error
+          raise CannotParseImage
+        end
+
+        read_fiber = Fiber.new do
+          while data = gzip.readline
+            Fiber.yield data
+          end
+          nil
+        end
+      end
+
+      parse_packets FiberStream.new(read_fiber)
+
+      break  # needed to actively quit out of the fetch
+    end
+  end
+
+  def protocol_relative_url?(url)
+    url.start_with?("//")
+  end
+
+  def proxy_uri
+    begin
+      if @options[:proxy]
+        proxy = URI.parse(@options[:proxy])
+      else
+        proxy = ENV['http_proxy'] && ENV['http_proxy'] != "" ? URI.parse(ENV['http_proxy']) : nil
+      end
+    rescue URI::InvalidURIError
+      proxy = nil
+    end
+    proxy
+  end
+
+  def setup_http
+    proxy = proxy_uri
+
+    if proxy
+      @http = Net::HTTP::Proxy(proxy.host, proxy.port, proxy.user, proxy.password).new(@parsed_uri.host, @parsed_uri.port)
+    else
+      @http = Net::HTTP.new(@parsed_uri.host, @parsed_uri.port)
+    end
+    @http.use_ssl = (@parsed_uri.scheme == "https")
+    @http.verify_mode = OpenSSL::SSL::VERIFY_NONE
+    @http.open_timeout = @options[:timeout]
+    @http.read_timeout = @options[:timeout]
+  end
+
+  def fetch_using_read(readable)
+    return @content_length = readable.size if @property == :content_length && readable.respond_to?(:size)
+
+    readable.rewind if readable.respond_to?(:rewind)
+    # Pathnames respond to read, but always return the first
+    # chunk of the file unlike an IO (even though the
+    # docuementation for it refers to IO). Need to supply
+    # an offset in this case.
+    if readable.is_a?(Pathname)
+      read_fiber = Fiber.new do
+        offset = 0
+        while str = readable.read(LocalFileChunkSize, offset)
+          Fiber.yield str
+          offset += LocalFileChunkSize
+        end
+        nil
+      end
+    else
+      read_fiber = Fiber.new do
+        while str = readable.read(LocalFileChunkSize)
+          Fiber.yield str
+        end
+        nil
+      end
+    end
+
+    parse_packets FiberStream.new(read_fiber)
+  end
+
+  def fetch_using_file_open
+    return @content_length = File.size?(@uri) if @property == :content_length
+
+    File.open(@uri) do |s|
+      fetch_using_read(s)
+    end
+  end
+
+  def fetch_using_base64(uri)
+    decoded = begin
+      uri.split(',')[1].unpack("m").first
+    rescue
+      raise CannotParseImage
+    end
+
+    fetch_using_read StringIO.new(decoded)
+  end
+  
+  def parse_packets(stream)
+    @stream = stream
+
+    begin
+      @type = TypeParser.new(@stream).type unless defined?(@type)
+
+      result = case @property
+      when :type
+        @type
+      when :size
+        parse_size
+      when :animated
+        parse_animated
+      end
+
+      if result != nil
+        # extract exif orientation if it was found
+        if @property == :size && result.size == 3
+          @orientation = result.pop
+        else
+          @orientation = 1
+        end
+
+        instance_variable_set("@#{@property}", result)
+      else
+        raise CannotParseImage
+      end
+    rescue FiberError
+      raise CannotParseImage
+    end
+  end
+
+  def parser_class
+    klass = Parsers[@type]
+    raise UnknownImageType unless klass
+    klass
+  end
+
+  def parse_size
+    parser_class.new(@stream).dimensions
+  end
+
+  def parse_animated
+    parser_class.new(@stream).animated?
+  end
+end

lib/fastimage/fastimage_parsing/avif.rb

@@ -0,0 +1,12 @@
+module FastImageParsing
+  class Avif < ImageBase # :nodoc:  
+    def dimensions
+      bmff = IsoBmff.new(@stream)
+      [bmff.width, bmff.height]
+    end
+  
+    def animated?
+      @stream.peek(12)[4..-1] == "ftypavis"
+    end
+  end
+end

lib/fastimage/fastimage_parsing/bmp.rb

@@ -0,0 +1,17 @@
+module FastImageParsing
+  class Bmp < ImageBase # :nodoc:
+    def dimensions
+      d = @stream.read(32)[14..28]
+      header = d.unpack("C")[0]
+
+      result = if header == 12
+                 d[4..8].unpack('SS')
+               else
+                 d[4..-1].unpack('l<l<')
+               end
+
+      # ImageHeight is expressed in pixels. The absolute value is necessary because ImageHeight can be negative
+      [result.first, result.last.abs]
+    end
+  end
+end

lib/fastimage/fastimage_parsing/exif.rb

@@ -0,0 +1,76 @@
+module FastImageParsing
+  class Exif # :nodoc:
+    attr_reader :width, :height, :orientation
+  
+    def initialize(stream)
+      @stream = stream
+      @width, @height, @orientation = nil
+      parse_exif
+    end
+  
+    def rotated?
+      @orientation >= 5
+    end
+  
+    private
+  
+    def get_exif_byte_order
+      byte_order = @stream.read(2)
+      case byte_order
+      when 'II'
+        @short, @long = 'v', 'V'
+      when 'MM'
+        @short, @long = 'n', 'N'
+      else
+        raise FastImage::CannotParseImage
+      end
+    end
+  
+    def parse_exif_ifd
+      tag_count = @stream.read(2).unpack(@short)[0]
+      tag_count.downto(1) do
+        type = @stream.read(2).unpack(@short)[0]
+        data_type = @stream.read(2).unpack(@short)[0]
+        @stream.read(4)
+
+        if data_type == 4
+          data = @stream.read(4).unpack(@long)[0]
+        else
+          data = @stream.read(2).unpack(@short)[0]
+          @stream.read(2)
+        end
+
+        case type
+        when 0x0100 # image width
+          @width = data
+        when 0x0101 # image height
+          @height = data
+        when 0x0112 # orientation
+          @orientation = data
+        end
+        if @width && @height && @orientation
+          return # no need to parse more
+        end
+      end
+    end
+  
+    def parse_exif
+      @start_byte = @stream.pos
+  
+      get_exif_byte_order
+  
+      @stream.read(2) # 42
+  
+      offset = @stream.read(4).unpack(@long)[0]
+      if @stream.respond_to?(:skip)
+        @stream.skip(offset - 8)
+      else
+        @stream.read(offset - 8)
+      end
+  
+      parse_exif_ifd
+  
+      @orientation ||= 1
+    end
+  end
+end

lib/fastimage/fastimage_parsing/fiber_stream.rb

@@ -0,0 +1,58 @@
+module FastImageParsing
+  class FiberStream # :nodoc:
+    include StreamUtil
+    attr_reader :pos
+  
+    # read_fiber should return nil if it no longer has anything to return when resumed
+    # so the result of the whole Fiber block should be set to be nil in case yield is no
+    # longer called
+    def initialize(read_fiber)
+      @read_fiber = read_fiber
+      @pos = 0
+      @strpos = 0
+      @str = ''
+    end
+  
+    # Peeking beyond the end of the input will raise
+    def peek(n)
+      while @strpos + n > @str.size
+        unused_str = @str[@strpos..-1]
+  
+        new_string = @read_fiber.resume
+        raise FastImage::CannotParseImage if !new_string
+        # we are dealing with bytes here, so force the encoding
+        new_string.force_encoding("ASCII-8BIT") if new_string.respond_to? :force_encoding
+  
+        @str = unused_str + new_string
+        @strpos = 0
+      end
+  
+      @str[@strpos, n]
+    end
+  
+    def read(n)
+      result = peek(n)
+      @strpos += n
+      @pos += n
+      result
+    end
+  
+    def skip(n)
+      discarded = 0
+      fetched = @str[@strpos..-1].size
+      while n > fetched
+        discarded += @str[@strpos..-1].size
+        new_string = @read_fiber.resume
+        raise FastImage::CannotParseImage if !new_string
+  
+        new_string.force_encoding("ASCII-8BIT") if new_string.respond_to? :force_encoding
+  
+        fetched += new_string.size
+        @str = new_string
+        @strpos = 0
+      end
+      @strpos = @strpos + n - discarded
+      @pos += n
+    end
+  end
+end

lib/fastimage/fastimage_parsing/gif.rb

@@ -0,0 +1,63 @@
+module FastImageParsing
+  class Gif < ImageBase # :nodoc:  
+    def dimensions
+      @stream.read(11)[6..10].unpack('SS')
+    end
+  
+    # Checks for multiple frames
+    def animated?
+      frames = 0
+  
+      # "GIF" + version (3) + width (2) + height (2)
+      @stream.skip(10)
+  
+      # fields (1) + bg color (1) + pixel ratio (1)
+      fields = @stream.read(3).unpack("CCC")[0]
+      if fields & 0x80 != 0 # Global Color Table
+        # 2 * (depth + 1) colors, each occupying 3 bytes (RGB)
+        @stream.skip(3 * 2 ** ((fields & 0x7) + 1))
+      end
+  
+      loop do
+        block_type = @stream.read(1).unpack("C")[0]
+  
+        if block_type == 0x21 # Graphic Control Extension
+          # extension type (1) + size (1)
+          size = @stream.read(2).unpack("CC")[1]
+          @stream.skip(size)
+          skip_sub_blocks
+        elsif block_type == 0x2C # Image Descriptor
+          frames += 1
+          return true if frames > 1
+  
+          # left position (2) + top position (2) + width (2) + height (2) + fields (1)
+          fields = @stream.read(9).unpack("SSSSC")[4]
+          if fields & 0x80 != 0 # Local Color Table
+            # 2 * (depth + 1) colors, each occupying 3 bytes (RGB)
+            @stream.skip(3 * 2 ** ((fields & 0x7) + 1))
+          end
+  
+          @stream.skip(1) # LZW min code size (1)
+          skip_sub_blocks
+        else
+          break # unrecognized block
+        end
+      end
+  
+      false
+    end
+  
+    private
+  
+    def skip_sub_blocks
+      loop do
+        size = @stream.read(1).unpack("C")[0]
+        if size == 0
+          break
+        else
+          @stream.skip(size)
+        end
+      end
+    end
+  end
+end

lib/fastimage/fastimage_parsing/heic.rb

@@ -0,0 +1,8 @@
+module FastImageParsing
+  class Heic < ImageBase # :nodoc:
+    def dimensions
+      bmff = IsoBmff.new(@stream)
+      [bmff.width, bmff.height]
+    end
+  end
+end

lib/fastimage/fastimage_parsing/ico.rb

@@ -0,0 +1,9 @@
+module FastImageParsing
+  class Ico < ImageBase
+    def dimensions
+      icons = @stream.read(6)[4..5].unpack('v').first
+      sizes = icons.times.map { @stream.read(16).unpack('C2').map { |x| x == 0 ? 256 : x } }.sort_by { |w,h| w * h }
+      sizes.last
+    end
+  end
+end

lib/fastimage/fastimage_parsing/image_base.rb

@@ -0,0 +1,17 @@
+module FastImageParsing
+  class ImageBase # :nodoc:
+    def initialize(stream)
+      @stream = stream
+    end
+  
+    # Implement in subclasses
+    def dimensions
+      raise NotImplementedError
+    end
+    
+    # Implement in subclasses if appropriate
+    def animated?
+      nil
+    end
+  end
+end

lib/fastimage/fastimage_parsing/iso_bmff.rb

@@ -0,0 +1,176 @@
+module FastImageParsing
+  # HEIC/AVIF are a special case of the general ISO_BMFF format, in which all data is encapsulated in typed boxes,
+  # with a mandatory ftyp box that is used to indicate particular file types. Is composed of nested "boxes". Each
+  # box has a header composed of
+  # - Size (32 bit integer)
+  # - Box type (4 chars)
+  # - Extended size: only if size === 1, the type field is followed by 64 bit integer of extended size
+  # - Payload: Type-dependent
+  class IsoBmff # :nodoc:
+    attr_reader :width, :height
+  
+    def initialize(stream)
+      @stream = stream
+      @width, @height = nil
+      parse_isobmff
+    end
+    
+    def parse_isobmff
+      @rotation = 0
+      @max_size = nil
+      @primary_box = nil
+      @ipma_boxes = []
+      @ispe_boxes = []
+      @final_size = nil
+
+      catch :finish do
+        read_boxes!
+      end
+
+      if [90, 270].include?(@rotation)
+        @final_size.reverse!
+      end
+      
+      @width, @height = @final_size
+    end
+
+    private
+
+    # Format specs: https://www.loc.gov/preservation/digital/formats/fdd/fdd000525.shtml
+
+    # If you need to inspect a heic/heif file, use
+    # https://gpac.github.io/mp4box.js/test/filereader.html
+    def read_boxes!(max_read_bytes = nil)
+      end_pos = max_read_bytes.nil? ? nil : @stream.pos + max_read_bytes
+      index = 0
+
+      loop do
+        return if end_pos && @stream.pos >= end_pos
+
+        box_type, box_size = read_box_header!
+
+        case box_type
+        when "meta"
+          handle_meta_box(box_size)
+        when "pitm"
+          handle_pitm_box(box_size)
+        when "ipma"
+          handle_ipma_box(box_size)
+        when "hdlr"
+          handle_hdlr_box(box_size)
+        when "iprp", "ipco"
+          read_boxes!(box_size)
+        when "irot"
+          handle_irot_box
+        when "ispe"
+          handle_ispe_box(box_size, index)
+        when "mdat"
+          @stream.skip(box_size)
+        when "jxlc"
+          handle_jxlc_box(box_size)
+        else
+          @stream.skip(box_size)
+        end
+
+        index += 1
+      end
+    end
+
+    def handle_irot_box
+      @rotation = (read_uint8! & 0x3) * 90
+    end
+
+    def handle_ispe_box(box_size, index)
+      throw :finish if box_size < 12
+
+      data = @stream.read(box_size)
+      width, height = data[4...12].unpack("N2")
+      @ispe_boxes << { index: index, size: [width, height] }
+    end
+
+    def handle_hdlr_box(box_size)
+      throw :finish if box_size < 12
+
+      data = @stream.read(box_size)
+      throw :finish if data[8...12] != "pict"
+    end
+
+    def handle_ipma_box(box_size)
+      @stream.read(3)
+      flags3 = read_uint8!
+      entries_count = read_uint32!
+
+      entries_count.times do
+        id = read_uint16!
+        essen_count = read_uint8!
+
+        essen_count.times do
+          property_index = read_uint8! & 0x7F
+
+          if flags3 & 1 == 1
+            property_index = (property_index << 7) + read_uint8!
+          end
+
+          @ipma_boxes << { id: id, property_index: property_index - 1 }
+        end
+      end
+    end
+
+    def handle_pitm_box(box_size)
+      data = @stream.read(box_size)
+      @primary_box = data[4...6].unpack("S>")[0]
+    end
+
+    def handle_meta_box(box_size)
+      throw :finish if box_size < 4
+
+      @stream.read(4)
+      read_boxes!(box_size - 4)
+
+      throw :finish if !@primary_box
+
+      primary_indices = @ipma_boxes
+                        .select { |box| box[:id] == @primary_box }
+                        .map { |box| box[:property_index] }
+
+      ispe_box = @ispe_boxes.find do |box|
+        primary_indices.include?(box[:index])
+      end
+
+      if ispe_box
+        @final_size = ispe_box[:size]
+      end
+
+      throw :finish
+    end
+
+    def handle_jxlc_box(box_size)
+      jxlc = Jxlc.new(@stream)
+      @final_size = [jxlc.width, jxlc.height]
+      throw :finish
+    end
+
+    def read_box_header!
+      size = read_uint32!
+      type = @stream.read(4)
+      size = read_uint64! - 8 if size == 1
+      [type, size - 8]
+    end
+
+    def read_uint8!
+      @stream.read(1).unpack("C")[0]
+    end
+
+    def read_uint16!
+      @stream.read(2).unpack("S>")[0]
+    end
+
+    def read_uint32!
+      @stream.read(4).unpack("N")[0]
+    end
+
+    def read_uint64!
+      @stream.read(8).unpack("Q>")[0]
+    end
+  end
+end

lib/fastimage/fastimage_parsing/jpeg.rb

@@ -0,0 +1,52 @@
+module FastImageParsing
+  class IOStream < SimpleDelegator # :nodoc:
+    include StreamUtil
+  end
+  
+  class Jpeg < ImageBase # :nodoc:
+    def dimensions
+      exif = nil
+      state = nil
+      loop do
+        state = case state
+        when nil
+          @stream.skip(2)
+          :started
+        when :started
+          @stream.read_byte == 0xFF ? :sof : :started
+        when :sof
+          case @stream.read_byte
+          when 0xe1 # APP1
+            skip_chars = @stream.read_int - 2
+            data = @stream.read(skip_chars)
+            io = StringIO.new(data)
+            if io.read(4) == "Exif"
+              io.read(2)
+              new_exif = Exif.new(IOStream.new(io)) rescue nil
+              exif ||= new_exif # only use the first APP1 segment
+            end
+            :started
+          when 0xe0..0xef
+            :skipframe
+          when 0xC0..0xC3, 0xC5..0xC7, 0xC9..0xCB, 0xCD..0xCF
+            :readsize
+          when 0xFF
+            :sof
+          else
+            :skipframe
+          end
+        when :skipframe
+          skip_chars = @stream.read_int - 2
+          @stream.skip(skip_chars)
+          :started
+        when :readsize
+          @stream.skip(3)
+          height = @stream.read_int
+          width = @stream.read_int
+          width, height = height, width if exif && exif.rotated?
+          return [width, height, exif ? exif.orientation : 1]
+        end
+      end
+    end
+  end
+end

lib/fastimage/fastimage_parsing/jxl.rb

@@ -0,0 +1,13 @@
+module FastImageParsing
+  class Jxl < ImageBase # :nodoc:
+    def dimensions
+      if @stream.peek(2) == "\xFF\x0A".b
+        jxlc = Jxlc.new(@stream)
+        [jxlc.width, jxlc.height]
+      else
+        bmff = IsoBmff.new(@stream)
+        [bmff.width, bmff.height]
+      end
+    end
+  end
+end

lib/fastimage/fastimage_parsing/jxlc.rb

@@ -0,0 +1,75 @@
+module FastImageParsing
+  class Jxlc # :nodoc:
+    attr_reader :width, :height
+
+    LENGTHS = [9, 13, 18, 30]
+    MULTIPLIERS = [1, 1.2, Rational(4, 3), 1.5, Rational(16, 9), 1.25, 2]
+  
+    def initialize(stream)
+      @stream = stream
+      @width, @height´ = nil
+      @bit_counter = 0
+      parse_jxlc
+    end
+    
+    def parse_jxlc
+      @words = @stream.read(6)[2..5].unpack('vv')
+
+      # small mode allows for values <= 256 that are divisible by 8
+      small = get_bits(1)
+      if small == 1
+        y = (get_bits(5) + 1) * 8
+        x = x_from_ratio(y)
+        if !x
+          x = (get_bits(5) + 1) * 8
+        end
+        @width, @height = x, y
+        return
+      end
+
+      len = LENGTHS[get_bits(2)]
+      y = get_bits(len) + 1
+      x = x_from_ratio(y)
+      if !x
+        len = LENGTHS[get_bits(2)]
+        x = get_bits(len) + 1
+      end
+      @width, @height = x, y
+    end
+
+    def get_bits(size)
+      if @words.size < (@bit_counter + size) / 16 + 1
+        @words += @stream.read(4).unpack('vv')
+      end
+
+      dest_pos = 0
+      dest = 0
+      size.times do
+        word = @bit_counter / 16
+        source_pos = @bit_counter % 16
+        dest |= ((@words[word] & (1 << source_pos)) > 0 ? 1 : 0) << dest_pos
+        dest_pos += 1
+        @bit_counter += 1
+      end
+      dest
+    end
+
+    def x_from_ratio(y)
+      ratio = get_bits(3)
+      if ratio == 0
+        return nil
+      else
+        return (y * MULTIPLIERS[ratio - 1]).to_i
+      end
+    end
+  end
+
+  def parse_size_for_jxl
+    if @stream.peek(2) == "\xFF\x0A".b
+      JXL.new(@stream).read_size_header
+    else
+      bmff = IsoBmff.new(@stream)
+      bmff.width_and_height
+    end
+  end
+end

lib/fastimage/fastimage_parsing/png.rb

@@ -0,0 +1,26 @@
+module FastImageParsing
+  class Png < ImageBase # :nodoc:
+    def dimensions
+      @stream.read(25)[16..24].unpack('NN')
+    end
+    
+    def animated?
+      # Signature (8) + IHDR chunk (4 + 4 + 13 + 4)
+      @stream.read(33)
+
+      loop do
+        length = @stream.read(4).unpack("L>")[0]
+        type = @stream.read(4)
+
+        case type
+        when "acTL"
+          return true
+        when "IDAT"
+          return false
+        end
+
+        @stream.skip(length + 4)
+      end
+    end
+  end
+end

lib/fastimage/fastimage_parsing/psd.rb

@@ -0,0 +1,7 @@
+module FastImageParsing
+  class Psd < ImageBase # :nodoc:
+    def dimensions
+      @stream.read(26).unpack("x14NN").reverse
+    end
+  end
+end

lib/fastimage/fastimage_parsing/stream_util.rb

@@ -0,0 +1,19 @@
+module FastImageParsing
+  module StreamUtil # :nodoc:
+    def read_byte
+      read(1)[0].ord
+    end
+  
+    def read_int
+      read(2).unpack('n')[0]
+    end
+  
+    def read_string_int
+      value = []
+      while read(1) =~ /(\d)/
+        value << $1
+      end
+      value.join.to_i
+    end
+  end
+end

lib/fastimage/fastimage_parsing/svg.rb

@@ -0,0 +1,69 @@
+module FastImageParsing
+  class Svg < ImageBase # :nodoc:
+    def dimensions
+      @width, @height, @ratio, @viewbox_width, @viewbox_height = nil
+
+      parse_svg
+      
+      if @width && @height
+        [@width, @height]
+      elsif @width && @ratio
+        [@width, @width / @ratio]
+      elsif @height && @ratio
+        [@height * @ratio, @height]
+      elsif @viewbox_width && @viewbox_height
+        [@viewbox_width, @viewbox_height]
+      else
+        nil
+      end
+    end
+  
+    private
+  
+    def parse_svg
+      attr_name = []
+      state = nil
+  
+      while (char = @stream.read(1)) && state != :stop do
+        case char
+        when "="
+          if attr_name.join =~ /width/i
+            @stream.read(1)
+            @width = @stream.read_string_int
+            return if @height
+          elsif attr_name.join =~ /height/i
+            @stream.read(1)
+            @height = @stream.read_string_int
+            return if @width
+          elsif attr_name.join =~ /viewbox/i
+            values = attr_value.split(/\s/)
+            if values[2].to_f > 0 && values[3].to_f > 0
+              @ratio = values[2].to_f / values[3].to_f
+              @viewbox_width = values[2].to_i
+              @viewbox_height = values[3].to_i
+            end
+          end
+        when /\w/
+          attr_name << char
+        when "<"
+          attr_name = [char]
+        when ">"
+          state = :stop if state == :started
+        else
+          state = :started if attr_name.join == "<svg"
+          attr_name.clear
+        end
+      end
+    end
+  
+    def attr_value
+      @stream.read(1)
+  
+      value = []
+      while @stream.read(1) =~ /([^"])/
+        value << $1
+      end
+      value.join
+    end
+  end
+end

lib/fastimage/fastimage_parsing/tiff.rb

@@ -0,0 +1,16 @@
+module FastImageParsing
+  class Tiff < ImageBase # :nodoc:
+    def initialize(stream)
+      @stream = stream
+    end
+  
+    def dimensions
+      exif = Exif.new(@stream)
+      if exif.rotated?
+        [exif.height, exif.width, exif.orientation]
+      else
+        [exif.width, exif.height, exif.orientation]
+      end
+    end
+  end
+end

lib/fastimage/fastimage_parsing/type_parser.rb

@@ -0,0 +1,69 @@
+module FastImageParsing
+  class TypeParser
+    def initialize(stream)
+      @stream = stream
+    end
+    
+    # type will use peek to get enough bytes to determing the type of the image
+    def type
+      parsed_type = case @stream.peek(2)
+      when "BM"
+        :bmp
+      when "GI"
+        :gif
+      when 0xff.chr + 0xd8.chr
+        :jpeg
+      when 0x89.chr + "P"
+        :png
+      when "II", "MM"
+        case @stream.peek(11)[8..10]
+        when "APC", "CR\002"
+          nil  # do not recognise CRW or CR2 as tiff
+        else
+          :tiff
+        end
+      when '8B'
+        :psd
+      when "\xFF\x0A".b
+        :jxl
+      when "\0\0"
+        case @stream.peek(3).bytes.to_a.last
+        when 0
+          # http://www.ftyps.com/what.html
+          case @stream.peek(12)[4..-1]
+          when "ftypavif"
+            :avif
+          when "ftypavis"
+            :avif
+          when "ftypheic"
+            :heic
+          when "ftypmif1"
+            :heif
+          else
+            if @stream.peek(7)[4..-1] == 'JXL'
+              :jxl
+            end
+          end
+        # ico has either a 1 (for ico format) or 2 (for cursor) at offset 3
+        when 1 then :ico
+        when 2 then :cur
+        end
+      when "RI"
+        :webp if @stream.peek(12)[8..11] == "WEBP"
+      when "<s"
+        :svg if @stream.peek(4) == "<svg"
+      when /\s\s|\s<|<[?!]/, 0xef.chr + 0xbb.chr
+        # Peek 10 more chars each time, and if end of file is reached just raise
+        # unknown. We assume the <svg tag cannot be within 10 chars of the end of
+        # the file, and is within the first 1000 chars.
+        begin
+          :svg if (1..100).detect {|n| @stream.peek(10 * n).include?("<svg")}
+        rescue FiberError, FastImage::CannotParseImage
+          nil
+        end
+      end
+
+      parsed_type or raise FastImage::UnknownImageType
+    end
+  end
+end

lib/fastimage/fastimage_parsing/webp.rb

@@ -0,0 +1,60 @@
+module FastImageParsing
+  class Webp < ImageBase # :nodoc:
+    def dimensions
+      vp8 = @stream.read(16)[12..15]
+      _len = @stream.read(4).unpack("V")
+      case vp8
+      when "VP8 "
+        parse_size_vp8
+      when "VP8L"
+        parse_size_vp8l
+      when "VP8X"
+        parse_size_vp8x
+      else
+        nil
+      end
+    end
+    
+    def animated?
+      vp8 = @stream.read(16)[12..15]
+      _len = @stream.read(4).unpack("V")
+      case vp8
+      when "VP8 "
+        false
+      when "VP8L"
+        false
+      when "VP8X"
+        flags = @stream.read(4).unpack("C")[0]
+        flags & 2 > 0
+      else
+        nil
+      end
+    end
+    
+    private
+  
+    def parse_size_vp8
+      w, h = @stream.read(10).unpack("@6vv")
+      [w & 0x3fff, h & 0x3fff]
+    end
+
+    def parse_size_vp8l
+      @stream.skip(1) # 0x2f
+      b1, b2, b3, b4 = @stream.read(4).bytes.to_a
+      [1 + (((b2 & 0x3f) << 8) | b1), 1 + (((b4 & 0xF) << 10) | (b3 << 2) | ((b2 & 0xC0) >> 6))]
+    end
+
+    def parse_size_vp8x
+      flags = @stream.read(4).unpack("C")[0]
+      b1, b2, b3, b4, b5, b6 = @stream.read(6).unpack("CCCCCC")
+      width, height = 1 + b1 + (b2 << 8) + (b3 << 16), 1 + b4 + (b5 << 8) + (b6 << 16)
+
+      if flags & 8 > 0 # exif
+        # parse exif for orientation
+        # TODO: find or create test images for this
+      end
+
+      [width, height]
+    end
+  end
+end

lib/fastimage/version.rb

@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+class FastImage
+  VERSION = '2.4.0'
+end