require 'tempfile'
require 'subexec'
require 'stringio'
require 'pathname'
module MiniMagick
class << self
attr_accessor :processor
attr_accessor :timeout
# Experimental method for automatically selecting a processor
# such as gm. Only works on *nix.
#
# TODO: Write tests for this and figure out what platforms it supports
def choose_processor
if `type -P mogrify`.size > 0
return
elsif `type -P gm`.size > 0
self.processor = "gm"
end
end
def image_magick_version
@@version ||= Gem::Version.create(`mogrify --version`.split(" ")[2].split("-").first)
end
def minimum_image_magick_version
@@minimum_version ||= Gem::Version.create("6.6.3")
end
def valid_version_installed?
image_magick_version >= minimum_image_magick_version
end
end
MOGRIFY_COMMANDS = %w{adaptive-blur adaptive-resize adaptive-sharpen adjoin affine alpha annotate antialias append authenticate auto-gamma auto-level auto-orient background bench iterations bias black-threshold blue-primary point blue-shift factor blur border bordercolor brightness-contrast caption string cdl filename channel type charcoal radius chop clip clamp clip-mask filename clip-path id clone index clut contrast-stretch coalesce colorize color-matrix colors colorspace type combine comment string compose operator composite compress type contrast convolve coefficients crop cycle amount decipher filename debug events define format:option deconstruct delay delete index density depth despeckle direction type dissolve display server dispose method distort type coefficients dither method draw string edge radius emboss radius encipher filename encoding type endian type enhance equalize evaluate operator evaluate-sequence operator extent extract family name fft fill filter type flatten flip floodfill flop font name format string frame function name fuzz distance fx expression gamma gaussian-blur geometry gravity type green-primary point help identify ifft implode amount insert index intent type interlace type interline-spacing interpolate method interword-spacing kerning label string lat layers method level limit type linear-stretch liquid-rescale log format loop iterations mask filename mattecolor median radius modulate monitor monochrome morph morphology method kernel motion-blur negate noise radius normalize opaque ordered-dither NxN orient type page paint radius ping pointsize polaroid angle posterize levels precision preview type print string process image-filter profile filename quality quantize quiet radial-blur angle raise random-threshold low,high red-primary point regard-warnings region remap filename render repage resample resize respect-parentheses roll rotate degrees sample sampling-factor scale scene seed segments selective-blur separate sepia-tone threshold set attribute shade degrees shadow sharpen shave shear sigmoidal-contrast size sketch solarize threshold splice spread radius strip stroke strokewidth stretch type style type swap indexes swirl degrees texture filename threshold thumbnail tile filename tile-offset tint transform transparent transparent-color transpose transverse treedepth trim type type undercolor unique-colors units type unsharp verbose version view vignette virtual-pixel method wave weight type white-point point white-threshold write filename}
IMAGE_CREATION_OPERATORS = %w{canvas caption gradient label logo pattern plasma radial radient rose text tile xc }
class Error < RuntimeError; end
class Invalid < StandardError; end
class Image
# @return [String] The location of the current working file
attr_accessor :path
# Class Methods
# -------------
class << self
# This is the primary loading method used by all of the other class methods.
#
# Use this to pass in a stream object. Must respond to Object#read(size) or be a binary string object (BLOBBBB)
#
# As a change from the old API, please try and use IOStream objects. They are much, much better and more efficient!
#
# Probably easier to use the #open method if you want to open a file or a URL.
#
# @param stream [IOStream, String] Some kind of stream object that needs to be read or is a binary String blob!
# @param ext [String] A manual extension to use for reading the file. Not required, but if you are having issues, give this a try.
# @return [Image]
def read(stream, ext = nil)
if stream.is_a?(String)
stream = StringIO.new(stream)
elsif stream.is_a?(File)
if File.respond_to?(:binread)
stream = StringIO.new File.binread(stream.path.to_s)
else
stream = StringIO.new File.open(stream.path.to_s,"rb") { |f| f.read }
end
end
create(ext) do |f|
while chunk = stream.read(8192)
f.write(chunk)
end
end
end
# @deprecated Please use Image.read instead!
def from_blob(blob, ext = nil)
warn "Warning: MiniMagick::Image.from_blob method is deprecated. Instead, please use Image.read"
create(ext) { |f| f.write(blob) }
end
# Creates an image object from a binary string blob which contains raw pixel data (i.e. no header data).
#
# === Returns
#
# * [Image] The loaded image.
#
# === Parameters
#
# * [blob] String -- Binary string blob containing raw pixel data.
# * [columns] Integer -- Number of columns.
# * [rows] Integer -- Number of rows.
# * [depth] Integer -- Bit depth of the encoded pixel data.
# * [map] String -- A code for the mapping of the pixel data. Example: 'gray' or 'rgb'.
# * [format] String -- The file extension of the image format to be used when creating the image object. Defaults to 'png'.
#
def import_pixels(blob, columns, rows, depth, map, format="png")
# Create an image object with the raw pixel data string:
image = create(".dat", validate = false) { |f| f.write(blob) }
# Use ImageMagick to convert the raw data file to an image file of the desired format:
converted_image_path = image.path[0..-4] + format
argument = "-size #{columns}x#{rows} -depth #{depth} #{map}:#{image.path} #{converted_image_path}"
cmd = CommandBuilder.new("convert", argument) #Example: convert -size 256x256 -depth 16 gray:blob.dat blob.png
image.run(cmd)
# Update the image instance with the path of the properly formatted image, and return:
image.path = converted_image_path
image
end
# Opens a specific image file either on the local file system or at a URI.
#
# Use this if you don't want to overwrite the image file.
#
# Extension is either guessed from the path or you can specify it as a second parameter.
#
# If you pass in what looks like a URL, we require 'open-uri' before opening it.
#
# @param file_or_url [String] Either a local file path or a URL that open-uri can read
# @param ext [String] Specify the extension you want to read it as
# @return [Image] The loaded image
def open(file_or_url, ext = nil)
file_or_url = file_or_url.to_s # Force it to be a String... hell or highwater
if file_or_url.include?("://")
require 'open-uri'
ext ||= File.extname(URI.parse(file_or_url).path)
self.read(Kernel::open(file_or_url), ext)
else
ext ||= File.extname(file_or_url)
File.open(file_or_url, "rb") do |f|
self.read(f, ext)
end
end
end
# @deprecated Please use MiniMagick::Image.open(file_or_url) now
def from_file(file, ext = nil)
warn "Warning: MiniMagick::Image.from_file is now deprecated. Please use Image.open"
open(file, ext)
end
# Used to create a new Image object data-copy. Not used to "paint" or that kind of thing.
#
# Takes an extension in a block and can be used to build a new Image object. Used
# by both #open and #read to create a new object! Ensures we have a good tempfile!
#
# @param ext [String] Specify the extension you want to read it as
# @param validate [Boolean] If false, skips validation of the created image. Defaults to true.
# @yield [IOStream] You can #write bits to this object to create the new Image
# @return [Image] The created image
def create(ext = nil, validate = true, &block)
begin
tempfile = Tempfile.new(['mini_magick', ext.to_s.downcase])
tempfile.binmode
block.call(tempfile)
tempfile.close
image = self.new(tempfile.path, tempfile)
if validate and !image.valid?
raise MiniMagick::Invalid
end
return image
ensure
tempfile.close if tempfile
end
end
end
# Create a new MiniMagick::Image object
#
# _DANGER_: The file location passed in here is the *working copy*. That is, it gets *modified*.
# you can either copy it yourself or use the MiniMagick::Image.open(path) method which creates a
# temporary file for you and protects your original!
#
# @param input_path [String] The location of an image file
# @todo Allow this to accept a block that can pass off to Image#combine_options
def initialize(input_path, tempfile = nil)
@path = input_path
@tempfile = tempfile # ensures that the tempfile will stick around until this image is garbage collected.
end
def escaped_path
Pathname.new(@path).to_s.inspect
end
# Checks to make sure that MiniMagick can read the file and understand it.
#
# This uses the 'identify' command line utility to check the file. If you are having
# issues with this, then please work directly with the 'identify' command and see if you
# can figure out what the issue is.
#
# @return [Boolean]
def valid?
run_command("identify", @path)
true
rescue MiniMagick::Invalid
false
end
# A rather low-level way to interact with the "identify" command. No nice API here, just
# the crazy stuff you find in ImageMagick. See the examples listed!
#
# @example
# image["format"] #=> "TIFF"
# image["height"] #=> 41 (pixels)
# image["width"] #=> 50 (pixels)
# image["colorspace"] #=> "DirectClassRGB"
# image["dimensions"] #=> [50, 41]
# image["size"] #=> 2050 (bits)
# image["original_at"] #=> 2005-02-23 23:17:24 +0000 (Read from Exif data)
# image["EXIF:ExifVersion"] #=> "0220" (Can read anything from Exif)
#
# @param format [String] A format for the "identify" command
# @see For reference see http://www.imagemagick.org/script/command-line-options.php#format
# @return [String, Numeric, Array, Time, Object] Depends on the method called! Defaults to String for unknown commands
def [](value)
# Why do I go to the trouble of putting in newlines? Because otherwise animated gifs screw everything up
case value.to_s
when "colorspace"
run_command("identify", "-quiet", "-format", format_option("%r"), escaped_path).split("\n")[0]
when "format"
run_command("identify", "-quiet", "-format", format_option("%m"), escaped_path).split("\n")[0]
when "height"
run_command("identify", "-quiet", "-format", format_option("%h"), escaped_path).split("\n")[0].to_i
when "width"
run_command("identify", "-quiet", "-format", format_option("%w"), escaped_path).split("\n")[0].to_i
when "dimensions"
run_command("identify", "-quiet", "-format", format_option("%w %h"), escaped_path).split("\n")[0].split.map{|v|v.to_i}
when "size"
File.size(@path) # Do this because calling identify -format "%b" on an animated gif fails!
when "original_at"
# Get the EXIF original capture as a Time object
Time.local(*self["EXIF:DateTimeOriginal"].split(/:|\s+/)) rescue nil
when /^EXIF\:/i
result = run_command('identify', '-quiet', '-format', "\"%[#{value}]\"", escaped_path).chop
if result.include?(",")
read_character_data(result)
else
result
end
else
run_command('identify', '-quiet', '-format', "\"#{value}\"", escaped_path).split("\n")[0]
end
end
# Sends raw commands to imagemagick's `mogrify` command. The image path is automatically appended to the command.
#
# Remember, we are always acting on this instance of the Image when messing with this.
#
# @return [String] Whatever the result from the command line is. May not be terribly useful.
def <<(*args)
run_command("mogrify", *args << escaped_path)
end
# This is used to change the format of the image. That is, from "tiff to jpg" or something like that.
# Once you run it, the instance is pointing to a new file with a new extension!
#
# *DANGER*: This renames the file that the instance is pointing to. So, if you manually opened the
# file with Image.new(file_path)... then that file is DELETED! If you used Image.open(file) then
# you are ok. The original file will still be there. But, any changes to it might not be...
#
# Formatting an animation into a non-animated type will result in ImageMagick creating multiple
# pages (starting with 0). You can choose which page you want to manipulate. We default to the
# first page.
#
# @param format [String] The target format... like 'jpg', 'gif', 'tiff', etc.
# @param page [Integer] If this is an animated gif, say which 'page' you want with an integer. Leave as default if you don't care.
# @return [nil]
def format(format, page = 0)
c = CommandBuilder.new('mogrify', '-format', format)
yield c if block_given?
c << @path
run(c)
old_path = @path.dup
@path.sub!(/(\.\w*)?$/, ".#{format}")
File.delete(old_path) if old_path != @path
unless File.exists?(@path)
begin
FileUtils.copy_file(@path.sub(".#{format}", "-#{page}.#{format}"), @path)
rescue => ex
raise MiniMagick::Error, "Unable to format to #{format}; #{ex}" unless File.exist?(@path)
end
end
ensure
Dir[@path.sub(/(\.\w+)?$/, "-[0-9]*.#{format}")].each do |fname|
File.unlink(fname)
end
end
# Collapse images with sequences to the first frame (ie. animated gifs) and
# preserve quality
def collapse!
run_command("mogrify", "-quality", "100", "#{path}[0]")
end
# Writes the temporary file out to either a file location (by passing in a String) or by
# passing in a Stream that you can #write(chunk) to repeatedly
#
# @param output_to [IOStream, String] Some kind of stream object that needs to be read or a file path as a String
# @return [IOStream, Boolean] If you pass in a file location [String] then you get a success boolean. If its a stream, you get it back.
# Writes the temporary image that we are using for processing to the output path
def write(output_to)
if output_to.kind_of?(String) || !output_to.respond_to?(:write)
FileUtils.copy_file @path, output_to
run_command "identify", output_to.to_s.inspect # Verify that we have a good image
else # stream
File.open(@path, "rb") do |f|
f.binmode
while chunk = f.read(8192)
output_to.write(chunk)
end
end
output_to
end
end
# Gives you raw image data back
# @return [String] binary string
def to_blob
f = File.new @path
f.binmode
f.read
ensure
f.close if f
end
def mime_type
format = self[:format]
"image/" + format.to_s.downcase
end
# If an unknown method is called then it is sent through the mogrify program
# Look here to find all the commands (http://www.imagemagick.org/script/mogrify.php)
def method_missing(symbol, *args)
combine_options do |c|
c.method_missing(symbol, *args)
end
end
# You can use multiple commands together using this method. Very easy to use!
#
# @example
# image.combine_options do |c|
# c.draw "image Over 0,0 10,10 '#{MINUS_IMAGE_PATH}'"
# c.thumbnail "300x500>"
# c.background background
# end
#
# @yieldparam command [CommandBuilder]
def combine_options(tool = :mogrify, &block)
c = CommandBuilder.new(tool)
c << @path if tool == :convert
block.call(c)
c << @path
run(c)
end
# Check to see if we are running on win32 -- we need to escape things differently
def windows?
RUBY_PLATFORM =~ /mswin|mingw|cygwin/
end
def composite(other_image, output_extension = 'jpg', &block)
begin
second_tempfile = Tempfile.new(output_extension)
second_tempfile.binmode
ensure
second_tempfile.close
end
command = CommandBuilder.new("composite")
block.call(command) if block
command.push(other_image.path)
command.push(self.path)
command.push(second_tempfile.path)
run(command)
return Image.new(second_tempfile.path, second_tempfile)
end
# Outputs a carriage-return delimited format string for Unix and Windows
def format_option(format)
windows? ? "\"#{format}\\n\"" : "\"#{format}\\\\n\""
end
def run_command(command, *args)
# -ping "efficiently determine image characteristics."
if command == 'identify'
args.unshift '-ping'
end
run(CommandBuilder.new(command, *args))
end
def run(command_builder)
command = command_builder.command
sub = Subexec.run(command, :timeout => MiniMagick.timeout)
if sub.exitstatus != 0
# Clean up after ourselves in case of an error
destroy!
# Raise the appropriate error
if sub.output =~ /no decode delegate/i || sub.output =~ /did not return an image/i
raise Invalid, sub.output
else
# TODO: should we do something different if the command times out ...?
# its definitely better for logging.. otherwise we dont really know
raise Error, "Command (#{command.inspect.gsub("\\", "")}) failed: #{{:status_code => sub.exitstatus, :output => sub.output}.inspect}"
end
else
sub.output
end
end
def destroy!
return if @tempfile.nil?
File.unlink(@tempfile.path) if File.exists?(@tempfile.path)
@tempfile = nil
end
private
# Sometimes we get back a list of character values
def read_character_data(list_of_characters)
chars = list_of_characters.gsub(" ", "").split(",")
result = ""
chars.each do |val|
result << ("%c" % val.to_i)
end
result
end
end
class CommandBuilder
attr :args
attr :command
def initialize(command, *options)
@command = command
@args = []
options.each { |arg| push(arg) }
end
def command
"#{MiniMagick.processor} #{@command} #{@args.join(' ')}".strip
end
def method_missing(symbol, *options)
guessed_command_name = symbol.to_s.gsub('_','-')
if guessed_command_name == "format"
raise Error, "You must call 'format' on the image object directly!"
elsif MOGRIFY_COMMANDS.include?(guessed_command_name)
add_command(guessed_command_name, *options)
self
elsif IMAGE_CREATION_OPERATORS.include?(guessed_command_name)
add_creation_operator(guessed_command_name, *options)
self
else
super(symbol, *args)
end
end
def +(*options)
push(@args.pop.gsub(/^-/, '+'))
if options.any?
options.each do |o|
push escape_string(o)
end
end
end
def add_command(command, *options)
push "-#{command}"
if options.any?
options.each do |o|
push escape_string(o)
end
end
end
def escape_string(value)
'"' + value + '"'
end
def add_creation_operator(command, *options)
creation_command = command
if options.any?
options.each do |option|
creation_command << ":#{option}"
end
end
push creation_command
end
def push(arg)
@args << arg.to_s.strip
end
alias :<< :push
end
end