Files
danbooru/app/logical/danbooru_image_resizer.rb
2018-10-24 23:06:12 -07:00

109 lines
3.8 KiB
Ruby

module DanbooruImageResizer
extend self
# Taken from ArgyllCMS 2.0.0 (see also: https://ninedegreesbelow.com/photography/srgb-profile-comparison.html)
SRGB_PROFILE = "#{Rails.root}/config/sRGB.icm"
# http://jcupitt.github.io/libvips/API/current/libvips-resample.html#vips-thumbnail
THUMBNAIL_OPTIONS = { size: :down, linear: false, auto_rotate: false, export_profile: SRGB_PROFILE, import_profile: SRGB_PROFILE }
# http://jcupitt.github.io/libvips/API/current/VipsForeignSave.html#vips-jpegsave
JPEG_OPTIONS = { background: 255, strip: true, interlace: true, optimize_coding: true }
CROP_OPTIONS = { linear: false, auto_rotate: false, export_profile: SRGB_PROFILE, import_profile: SRGB_PROFILE, crop: :attention }
# XXX libvips-8.4 on Debian doesn't support the `Vips::Image.thumbnail` method.
# On 8.4 we have to shell out to vipsthumbnail instead. Remove when Debian supports 8.5.
def resize(file, width, height, quality = 90)
if Vips.at_least_libvips?(8, 5)
resize_ruby(file, width, height, quality)
else
resize_shell(file, width, height, quality)
end
end
def crop(file, width, height, quality = 90)
crop_shell(file, width, height, quality)
end
# https://github.com/jcupitt/libvips/wiki/HOWTO----Image-shrinking
# http://jcupitt.github.io/libvips/API/current/Using-vipsthumbnail.md.html
def resize_ruby(file, width, height, resize_quality)
output_file = Tempfile.new
resized_image = Vips::Image.thumbnail(file.path, width, height: height, **THUMBNAIL_OPTIONS)
resized_image.jpegsave(output_file.path, Q: resize_quality, **JPEG_OPTIONS)
output_file
end
def crop_ruby(file, width, height, resize_quality)
return nil unless Danbooru.config.enable_image_cropping
output_file = Tempfile.new
resized_image = Vips::Image.thumbnail(file.path, width, height: height, **CROP_OPTIONS)
resized_image.jpegsave(output_file.path, Q: resize_quality, **JPEG_OPTIONS)
output_file
end
def resize_shell(file, width, height, quality)
output_file = Tempfile.new(["resize", ".jpg"])
# --size=WxH will upscale if the image is smaller than the target size.
# Fix the target size so that it's not bigger than the image.
image = Vips::Image.new_from_file(file.path)
target_width = [image.width, width].min
target_height = [image.height, height].min
arguments = [
file.path,
"--eprofile=#{SRGB_PROFILE}",
"--iprofile=#{SRGB_PROFILE}",
"--size=#{target_width}x#{target_height}",
"--format=#{output_file.path}[Q=#{quality},background=255,strip,interlace,optimize_coding]"
]
success = system("vipsthumbnail", *arguments)
raise RuntimeError, "vipsthumbnail failed (exit status: #{$?.exitstatus})" if !success
output_file
end
def crop_shell(file, width, height, quality)
return nil unless Danbooru.config.enable_image_cropping
output_file = Tempfile.new(["crop", ".jpg"])
# --size=WxH will upscale if the image is smaller than the target size.
# Fix the target size so that it's not bigger than the image.
image = Vips::Image.new_from_file(file.path)
arguments = [
file.path,
"--eprofile=#{SRGB_PROFILE}",
"--iprofile=#{SRGB_PROFILE}",
"--smartcrop=attention",
"--size=#{width}x#{height}",
"--format=#{output_file.path}[Q=#{quality},background=255,strip,interlace,optimize_coding]"
]
success = system("vipsthumbnail", *arguments)
raise RuntimeError, "vipsthumbnail failed (exit status: #{$?.exitstatus})" if !success
output_file
end
def validate_shell(file)
temp = Tempfile.new("validate")
output, status = Open3.capture2e("vips stats #{file.path} #{temp.path}.v")
# png | jpeg | gif
if output =~ /Read Error|Premature end of JPEG file|Failed to read from given file/m
return false
end
return true
ensure
temp.close
temp.unlink
end
end