Module: CarrierWave::MiniMagick
- Extended by:
- ActiveSupport::Concern
- Defined in:
- lib/carrierwave/processing/mini_magick.rb
Overview
This module simplifies manipulation with MiniMagick by providing a set of convenient helper methods. If you want to use them, you’ll need to require this file:
require 'carrierwave/processing/mini_magick'
And then include it in your uploader:
class MyUploader < CarrierWave::Uploader::Base
include CarrierWave::MiniMagick
end
You can now use the provided helpers:
class MyUploader < CarrierWave::Uploader::Base
include CarrierWave::MiniMagick
process :resize_to_fit => [200, 200]
end
Or create your own helpers with the powerful minimagick! method, which yields an ImageProcessing::Builder object. Check out the ImageProcessing docs at github.com/janko-m/image_processing and the list of all available ImageMagick options at www.imagemagick.org/script/command-line-options.php for more info.
class MyUploader < CarrierWave::Uploader::Base
include CarrierWave::MiniMagick
process :radial_blur => 10
def radial_blur(amount)
minimagick! do |builder|
builder.radial_blur(amount)
builder = yield(builder) if block_given?
builder
end
end
end
Note
The ImageProcessing gem uses MiniMagick, a mini replacement for RMagick that uses ImageMagick command-line tools, to build a “convert” command that performs the processing.
You can find more information here:
Defined Under Namespace
Modules: ClassMethods
Instance Method Summary collapse
-
#convert(format, page = nil, &block) ⇒ Object
Changes the image encoding format to the given format.
-
#height ⇒ Object
Returns the height of the image in pixels.
-
#manipulate! ⇒ Object
Manipulate the image with MiniMagick.
-
#minimagick!(block = nil) ⇒ Object
Process the image with MiniMagick, using the ImageProcessing gem.
-
#resize_and_pad(width, height, background = :transparent, gravity = 'Center', combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the original aspect ratio.
-
#resize_to_fill(width, height, gravity = 'Center', combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the aspect ratio of the original image.
-
#resize_to_fit(width, height, combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the original aspect ratio.
-
#resize_to_limit(width, height, combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the original aspect ratio.
-
#width ⇒ Object
Returns the width of the image in pixels.
Instance Method Details
#convert(format, page = nil, &block) ⇒ Object
Changes the image encoding format to the given format
See www.imagemagick.org/script/command-line-options.php#format
Parameters
- format (#to_s)
-
an abreviation of the format
Yields
- MiniMagick::Image
-
additional manipulations to perform
Examples
image.convert(:png)
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# File 'lib/carrierwave/processing/mini_magick.rb', line 101 def convert(format, page=nil, &block) minimagick!(block) do |builder| builder = builder.convert(format) builder = builder.loader(page: page) if page builder end end |
#height ⇒ Object
Returns the height of the image in pixels.
Returns
- Integer
-
the image’s height in pixels
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# File 'lib/carrierwave/processing/mini_magick.rb', line 231 def height mini_magick_image[:height] end |
#manipulate! ⇒ Object
Manipulate the image with MiniMagick. This method will load up an image and then pass each of its frames to the supplied block. It will then save the image to disk.
NOTE: This method exists mostly for backwards compatibility, you should probably use #minimagick!.
Gotcha
This method assumes that the object responds to current_path
. Any class that this module is mixed into must have a current_path
method. CarrierWave::Uploader does, so you won’t need to worry about this in most cases.
Yields
- MiniMagick::Image
-
manipulations to perform
Raises
- CarrierWave::ProcessingError
-
if manipulation failed.
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# File 'lib/carrierwave/processing/mini_magick.rb', line 258 def manipulate! cache_stored_file! if !cached? image = ::MiniMagick::Image.open(current_path) image = yield(image) FileUtils.mv image.path, current_path image.run_command("identify", current_path) rescue ::MiniMagick::Error, ::MiniMagick::Invalid => e = I18n.translate(:"errors.messages.mini_magick_processing_error", :e => e) raise CarrierWave::ProcessingError, ensure image.destroy! if image end |
#minimagick!(block = nil) ⇒ Object
Process the image with MiniMagick, using the ImageProcessing gem. This method will build a “convert” ImageMagick command and execute it on the current image.
Gotcha
This method assumes that the object responds to current_path
. Any class that this module is mixed into must have a current_path
method. CarrierWave::Uploader does, so you won’t need to worry about this in most cases.
Yields
- ImageProcessing::Builder
-
use it to define processing to be performed
Raises
- CarrierWave::ProcessingError
-
if processing failed.
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# File 'lib/carrierwave/processing/mini_magick.rb', line 291 def minimagick!(block = nil) builder = ImageProcessing::MiniMagick.source(current_path) builder = yield(builder) result = builder.call result.close # backwards compatibility (we want to eventually move away from MiniMagick::Image) if block image = MiniMagick::Image.new(result.path, result) image = block.call(image) result = image.instance_variable_get(:@tempfile) end FileUtils.mv result.path, current_path if File.extname(result.path) != File.extname(current_path) move_to = current_path.chomp(File.extname(current_path)) + File.extname(result.path) file.content_type = ::MiniMime.lookup_by_filename(move_to).content_type file.move_to(move_to, , ) end rescue ::MiniMagick::Error, ::MiniMagick::Invalid => e = I18n.translate(:"errors.messages.mini_magick_processing_error", :e => e) raise CarrierWave::ProcessingError, end |
#resize_and_pad(width, height, background = :transparent, gravity = 'Center', combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the original aspect ratio. If necessary, will pad the remaining area with the given color, which defaults to transparent (for gif and png, white for jpeg).
See www.imagemagick.org/script/command-line-options.php#gravity for gravity options.
Parameters
- width (Integer)
-
the width to scale the image to
- height (Integer)
-
the height to scale the image to
- background (String, :transparent)
-
the color of the background as a hexcode, like “#ff45de”
- gravity (String)
-
how to position the image
- combine_options (Hash)
-
additional ImageMagick options to apply before resizing
Yields
- MiniMagick::Image
-
additional manipulations to perform
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# File 'lib/carrierwave/processing/mini_magick.rb', line 204 def resize_and_pad(width, height, background=:transparent, gravity='Center', combine_options: {}, &block) width, height = resolve_dimensions(width, height) minimagick!(block) do |builder| builder.resize_and_pad(width, height, background: background, gravity: gravity) .apply() end end |
#resize_to_fill(width, height, gravity = 'Center', combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the aspect ratio of the original image. If necessary, crop the image in the larger dimension.
Parameters
- width (Integer)
-
the width to scale the image to
- height (Integer)
-
the height to scale the image to
- gravity (String)
-
the current gravity suggestion (default: ‘Center’; options: ‘NorthWest’, ‘North’, ‘NorthEast’, ‘West’, ‘Center’, ‘East’, ‘SouthWest’, ‘South’, ‘SouthEast’)
- combine_options (Hash)
-
additional ImageMagick options to apply before resizing
Yields
- MiniMagick::Image
-
additional manipulations to perform
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# File 'lib/carrierwave/processing/mini_magick.rb', line 174 def resize_to_fill(width, height, gravity = 'Center', combine_options: {}, &block) width, height = resolve_dimensions(width, height) minimagick!(block) do |builder| builder.resize_to_fill(width, height, gravity: gravity) .apply() end end |
#resize_to_fit(width, height, combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the original aspect ratio. The image may be shorter or narrower than specified in the smaller dimension but will not be larger than the specified values.
Parameters
- width (Integer)
-
the width to scale the image to
- height (Integer)
-
the height to scale the image to
- combine_options (Hash)
-
additional ImageMagick options to apply before resizing
Yields
- MiniMagick::Image
-
additional manipulations to perform
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# File 'lib/carrierwave/processing/mini_magick.rb', line 149 def resize_to_fit(width, height, combine_options: {}, &block) width, height = resolve_dimensions(width, height) minimagick!(block) do |builder| builder.resize_to_fit(width, height) .apply() end end |
#resize_to_limit(width, height, combine_options: {}, &block) ⇒ Object
Resize the image to fit within the specified dimensions while retaining the original aspect ratio. Will only resize the image if it is larger than the specified dimensions. The resulting image may be shorter or narrower than specified in the smaller dimension but will not be larger than the specified values.
Parameters
- width (Integer)
-
the width to scale the image to
- height (Integer)
-
the height to scale the image to
- combine_options (Hash)
-
additional ImageMagick options to apply before resizing
Yields
- MiniMagick::Image
-
additional manipulations to perform
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# File 'lib/carrierwave/processing/mini_magick.rb', line 125 def resize_to_limit(width, height, combine_options: {}, &block) width, height = resolve_dimensions(width, height) minimagick!(block) do |builder| builder.resize_to_limit(width, height) .apply() end end |
#width ⇒ Object
Returns the width of the image in pixels.
Returns
- Integer
-
the image’s width in pixels
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# File 'lib/carrierwave/processing/mini_magick.rb', line 220 def width mini_magick_image[:width] end |