Object
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
# File lib/mini_magick.rb, line 154 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
@deprecated Please use Image.read instead!
# File lib/mini_magick.rb, line 81 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
@deprecated Please use MiniMagick::Image.open(file_or_url) now
# File lib/mini_magick.rb, line 140 def from_file(file, ext = nil) warn "Warning: MiniMagick::Image.from_file is now deprecated. Please use Image.open" open(file, ext) end
Creates an image object from a binary string blob which contains raw pixel data (i.e. no header data).
The loaded image.
String -- Binary string blob containing raw pixel data.
Integer -- Number of columns.
Integer -- Number of rows.
Integer -- Bit depth of the encoded pixel data.
String -- A code for the mapping of the pixel data. Example: 'gray' or 'rgb'.
String -- The file extension of the image format to be used when creating the image object. Defaults to 'png'.
# File lib/mini_magick.rb, line 101 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
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
# File lib/mini_magick.rb, line 181 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
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
# File lib/mini_magick.rb, line 125 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
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]
# File lib/mini_magick.rb, line 62 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
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.
# File lib/mini_magick.rb, line 255 def <<(*args) run_command("mogrify", *args << escaped_path) 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 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
# File lib/mini_magick.rb, line 220 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\:/ 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
Collapse images with sequences to the first frame (ie. animated gifs) and preserve quality
# File lib/mini_magick.rb, line 298 def collapse! run_command("mogrify", "-quality", "100", "#{path}[0]") 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]
# File lib/mini_magick.rb, line 356 def combine_options(tool = :mogrify, &block) c = CommandBuilder.new(tool) c << @path if tool == :convert block.call(c) c << @path run(c) end
# File lib/mini_magick.rb, line 370 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
# File lib/mini_magick.rb, line 424 def destroy! return if @tempfile.nil? File.unlink(@tempfile.path) if File.exists?(@tempfile.path) @tempfile = nil end
# File lib/mini_magick.rb, line 186 def escaped_path Pathname.new(@path).to_s.inspect 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]
# File lib/mini_magick.rb, line 273 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
Outputs a carriage-return delimited format string for Unix and Windows
# File lib/mini_magick.rb, line 389 def format_option(format) windows? ? "\"#{format}\\n\"" : "\"#{format}\\\\n\"" end
If an unknown method is called then it is sent through the mogrify program Look here to find all the commands (www.imagemagick.org/script/mogrify.php)
# File lib/mini_magick.rb, line 340 def method_missing(symbol, *args) combine_options do |c| c.method_missing(symbol, *args) end end
# File lib/mini_magick.rb, line 333 def mime_type format = self[:format] "image/" + format.to_s.downcase end
# File lib/mini_magick.rb, line 402 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/ || sub.output =~ /did not return an image/ 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
# File lib/mini_magick.rb, line 393 def run_command(command, *args) # -ping "efficiently determine image characteristics." if command == 'identify' args.unshift '-ping' end run(CommandBuilder.new(command, *args)) end
Gives you raw image data back @return [String] binary string
# File lib/mini_magick.rb, line 325 def to_blob f = File.new @path f.binmode f.read ensure f.close if f 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]
# File lib/mini_magick.rb, line 197 def valid? run_command("identify", @path) true rescue MiniMagick::Invalid false end
Check to see if we are running on win32 – we need to escape things differently
# File lib/mini_magick.rb, line 366 def windows? RUBY_PLATFORM =~ /mswin|mingw|cygwin/ 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
# File lib/mini_magick.rb, line 308 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
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