ruby-on-rails - tutorial - file upload with carrierwave

Carrierwave RMagick no elimina la transparencia en convertir a jpg

Question

Estoy intentando subir un PNG y guardar un montón de miniaturas. Las miniaturas deberían ser JPG y no tener ninguna transparencia. De alguna manera, el archivo se guarda como jpg pero tiene transparencia ...

Aquí está mi Uploader:

# encoding: utf-8
class WinePhotoUploader < CarrierWave::Uploader::Base
# Include RMagick or MiniMagick support:
include CarrierWave::RMagick
# include CarrierWave::MiniMagick
# Choose what kind of storage to use for this uploader:
storage :file
# storage :fog
# Override the directory where uploaded files will be stored.
# This is a sensible default for uploaders that are meant to be mounted:
def store_dir
"assets/wines/#{version_name}"
end
CarrierWave::SanitizedFile.sanitize_regexp = /[^[:word:]/./-/+]/
# Provide a default URL as a default if there hasn''t been a file uploaded:
def default_url
# For Rails 3.1+ asset pipeline compatibility:
ActionController::Base.helpers.asset_path("pages/wines/#{version_name}/default.png")
end
process :for_all
process :convert => ''jpg''
version :croppable, :if => :new_upload? do
process :resize_and_pad => [1200, 1200, ''white'']
end
version :show, :if => :new_upload? do
process :resize_to_fit => [nil, ''425'']
end
version :general, :from_version => :show, :if => :new_upload? do
process :resize_and_pad => [150, 375, ''white'']
end
version :thumb, :from_version => :croppable, :if => :cropping? do
process :rotate_to => [-30]
process :crop_via_model
process :resize_to_fit => [150, 150]
end
def for_all
manipulate! do |img|
img.trim
img.gravity = Magick::CenterGravity
# I only use these two because this shit isn''t working...these don''t seem to help!
# Neither does the flatten method...even though other posts on stackoverflow.com say
# that it works.
img.background_color = ''white''
img.alpha Magick::OpaqueAlphaChannel
img.unsharp_mask 0.3, 0.3, 5, 0
img
end
end
def extend_to(w, h)
manipulate! do |img|
img.gravity = Magick::CenterGravity
img.extent w, h
img
end
end
def rotate_to(deg)
manipulate! do |img|
img.gravity = Magick::CenterGravity
img.distort Magick::ScaleRotateTranslateDistortion, deg
#img.repage # WTF?!?!?!? No repage method?!
img
end
end
def crop_via_model
manipulate! do |img|
img.gravity = Magick::CenterGravity
img.crop model.crop_x.to_i, model.crop_y.to_i, model.crop_w.to_i, model.crop_h.to_i
img
end
end
def flatten
manipulate! do |img|
img_list = Magick::ImageList.new
img_list.from_blob img.to_blob
img_list.new_image(img_list.first.columns, img_list.first.rows) { self.background_color = "white" } # Create new "layer" with white background and size of original image
img = img_list.reverse.flatten_images
img
end
end
def new_upload? picture
!model.cropping?
end
def cropping? picture
model.cropping?
end
# Add a white list of extensions which are allowed to be uploaded.
# For images you might use something like this:
def extension_white_list
%w(jpg jpeg gif png tif)
end
# Override the filename of the uploaded files:
# Avoid using model.id or version_name here, see uploader/store.rb for details.
def filename
"#{ model.get_permalink(:normalized => true) }.jpg"
end
# Remove this when https://github.com/carrierwaveuploader/carrierwave/issues/1164 is solved.
def recreate_versions!(*versions)
if versions.any?
from_versions = versions.group_by { |v| self.class.versions[v][:options][:from_version] }
from_versions.each do |from, versions|
next if from.nil?
file = CarrierWave::SanitizedFile.new(self.versions[from.to_sym].file)
store_versions!(file, versions)
end
else
super(*versions)
end
end
end

Oh ... y aparentemente carrierwave no parece querer registrar nada, así que no puedo decir lo que está haciendo.

Answer 1

Parece que hay una peculiaridad con imagemagick y el orden de las operaciones al convertir tipos de archivos.

El problema completo de github se puede encontrar aquí: https://github.com/carrierwaveuploader/carrierwave/issues/133#issuecomment-615254

Básicamente manipulate se llama una vez por cada process que tiene. manipulate abre la ruta actual del archivo, realiza cambios y luego escribe. Debido a esto, parece que las líneas de process que se llaman después de la conversión de formato se realizan en el archivo original, no en el archivo recién convertido.

Para solucionar esto, debe realizar todas sus operaciones de process dentro de un solo bloque de manipulate o asegurarse de que la conversión sea el último process en ejecutarse.

El ejemplo de esto del problema de Github es:

process :convert_and_scale
def convert_and_scale
manipulate! do |img|
img.format ''png''
img.resize ''100x32''
img
end
end