Class | MiniMagick::Image |
In: |
lib/mini_magick/image/info.rb
lib/mini_magick/image.rb |
Parent: | Object |
path | [R] | @return [String] The location of the current working file |
tempfile | [R] | @return [Tempfile] The underlying temporary file |
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 [Tempfile] You can write bits to this object to create the new
Image
@return [MiniMagick::Image] The created image
Creates an image object from a binary string blob which contains raw pixel data (i.e. no header data).
@param blob [String] Binary string blob containing raw pixel data. @param columns [Integer] Number of columns. @param rows [Integer] Number of rows. @param depth [Integer] Bit depth of the encoded pixel data. @param map [String] A code for the mapping of the pixel data. Example:
'gray' or 'rgb'.
@param format [String] The file extension of the image format to be
used when creating the image object.
Defaults to ‘png’. @return [MiniMagick::Image] The loaded image.
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 {.open} which creates a temporary file for you and protects your original.
@param input_path [String, Pathname] The location of an image file @yield [MiniMagick::Tool::Mogrify] If block is given, {combine_options}
is called.
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.
@param path_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 @param options [Hash] Specify options for the open method @return [MiniMagick::Image] The loaded image
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 read(size) or be a binary string object (BLOBBBB)
Probably easier to use the {.open} method if you want to open a file or a URL.
@param stream [read, 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 [MiniMagick::Image]
Use this method if you want to access raw Identify‘s format API.
@example
image["%w %h"] #=> "250 450" image["%r"] #=> "DirectClass sRGB"
@param value [String] @see www.imagemagick.org/script/escape.php @return [String]
Collapse images with sequences to the first frame (i.e. animated gifs) and preserve quality.
@param frame [Integer] The frame to which to collapse to, defaults to `0`. @return [self]
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 "blue" end
@yield [MiniMagick::Tool::Mogrify] @see www.imagemagick.org/script/mogrify.php @return [self]
@example
first_image = MiniMagick::Image.open "first.jpg" second_image = MiniMagick::Image.open "second.jpg" result = first_image.composite(second_image) do |c| c.compose "Over" # OverCompositeOp c.geometry "+20+20" # copy second_image onto first_image from (20, 20) end result.write "output.jpg"
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.
If you would like to convert between animated formats, pass nil as your page and ImageMagick will copy all of the pages.
@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. Default 0 will convert only the first page; 'nil' will convert all pages.
@param read_opts [Hash] Any read options to be passed to ImageMagick
for example: image.format('jpg', page, {density: '300'})
@yield [MiniMagick::Tool::Convert] It optionally yields the command,
if you want to add something.
@return [self]
Returns a matrix of pixels from the image. The matrix is constructed as an array (1) of arrays (2) of arrays (3) of unsigned integers:
1) one for each row of pixels 2) one for each column of pixels 3) three elements in the range 0-255, one for each of the RGB color channels
@example
img = MiniMagick::Image.open 'image.jpg' pixels = img.get_pixels pixels[3][2][1] # the green channel value from the 4th-row, 3rd-column pixel
It can also be called after applying transformations:
@example
img = MiniMagick::Image.open 'image.jpg' img.crop '20x30+10+5' img.colorspace 'Gray' pixels = img.get_pixels
In this example, all pixels in pix should now have equal R, G, and B values.
@return [Array] Matrix of each color of each pixel
Runs `identify` on itself. Accepts an optional block for adding more options to `identify`.
@example
image = MiniMagick::Image.open("image.jpg") image.identify do |b| b.verbose end # runs `identify -verbose image.jpg`
@return [String] Output from `identify` @yield [MiniMagick::Tool::Identify]
Returns layers of the image. For example, JPEGs are 1-layered, but formats like PSDs, GIFs and PDFs can have multiple layers/frames/pages.
@example
image = MiniMagick::Image.new("document.pdf") image.pages.each_with_index do |page, idx| page.write("page#{idx}.pdf") end
@return [Array<MiniMagick::Image>]
If an unknown method is called then it is sent through the mogrify program.
@see www.imagemagick.org/script/mogrify.php @return [self]
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]
Runs `identify` on the current image, and raises an error if it doesn‘t pass.
@raise [MiniMagick::Invalid]
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 [String, Pathname, read] Some kind of stream object
that needs to be read or a file path as a String