Webp-ffi | Ruby wrapper for libwebp

Webp-ffi [http://leopard.in.ua/webp-ffi/] Ruby wrapper for libwebp View the Project on GitHub le0pard/webp-ffi Download ZIP File Download TAR Ball View On GitHub Webp-ffi Ruby wrapper for libwebp. What is WebP? WebP is a new image format that provides lossless and lossy compression for images on the web. WebP lossless images are 26% smaller in size compared to PNGs. WebP lossy images are 25-34% smaller in size compared to JPEG images at equivalent SSIM index. WebP supports lossless transparency (also known as alpha channel) with just 22% additional bytes. Transparency is also supported with lossy compression and typically provides 3x smaller file sizes compared to PNG when lossy compression is acceptable for the red/green/blue color channels. WebP Gallery Installation Requirements First of all you should have install libraries: libpng, libjpeg and libtiff. For Ubuntu, Debian: sudo apt-get install libjpeg-dev libpng-dev libtiff-dev libwebp-dev For Fedora, CentOS: sudo dnf install libjpeg-devel libpng-devel libtiff-devel libwebp-devel For Mac OS: brew install libjpg libpng libtiff webp or (for MacPorts): sudo port install jpeg libpng tiff Next, you should install libwebp (if you didn’t install it by brew in Mac OS or by apt-get in Ubuntu or Debian). Webp library version should be >= 0.3.0. This gem is not support Windows systems. Final part Add this line to your application’s Gemfile: gem 'webp-ffi' And then execute: $ bundle Or install it yourself as: $ gem install webp-ffi Usage Encoder end Decoder versions Basic info about libwebp (encoder and decoder versions): $ irb 2.0.0p0 :001 > require 'webp_ffi' => true 2.0.0p0 :002 > WebP.decoder_version => "0.3.1" 2.0.0p0 :003 > WebP.encoder_version => "0.3.1" WebP size (width and height) Get size (width and height) from webp image: filename = File.expand_path(File.join(File.dirname(__FILE__), "spec/factories/4.webp")) WebP.webp_size(File.open(filename, "rb").read) => [2000, 2353] Encode WebP image Encode png, jpg or tiff image to webp: filename = File.expand_path(File.join(File.dirname(__FILE__), "spec/factories/4.png")) out_filename = File.expand_path(File.join(File.dirname(__FILE__), "tmp/4.webp")) WebP.encode(filename, out_filename) Encode png, jpg or tiff image to webp with options: WebP.encode(filename, out_filename, quality: 50, resize_w: 100, resize_h: 200) WebP.encode(filename, out_filename, quality: 75, crop_x: 0, cropt_y: 0, crop_w: 100, crop_h: 100) Possible encode options: lossless (int) - Lossless encoding (0=lossy(default), 1=lossless) quality (float) - between 0 (smallest file) and 100 (biggest) method (int) - quality/speed trade-off (0=fast, 6=slower-better) target_size (int) - if non-zero, set the desired target size in bytes. Takes precedence over the ‘compression’ parameter target_PSNR (float) - if non-zero, specifies the minimal distortion to try to achieve. Takes precedence over target_size segments (int) - maximum number of segments to use, in [1..4] sns_strength (int) - Spatial Noise Shaping. 0=off, 100=maximum filter_strength (int) - range: [0 = off .. 100 = strongest] filter_sharpness (int) - range: [0 = off .. 7 = least sharp] filter_type (int) - filtering type: 0 = simple, 1 = strong (only used if filter_strength > 0 or autofilter > 0) autofilter (int) - Auto adjust filter’s strength [0 = off, 1 = on] alpha_compression (int) - Algorithm for encoding the alpha plane (0 = none, 1 = compressed with WebP lossless). Default is 1 alpha_filtering (int) - Predictive filtering method for alpha plane. 0: none, 1: fast, 2: best. Default if 1 alpha_quality (int) - Between 0 (smallest size) and 100 (lossless). Default is 100 pass (int) - number of entropy-analysis passes (in [1..10]) show_compressed (int) - if true, export the compressed picture back. In-loop filtering is not applied preprocessing (int) - preprocessing filter (0=none, 1=segment-smooth) partitions (int) - log2(number of token partitions) in [0..3]. Default is set to 0 for easier progressive decoding partition_limit (int) - quality degradation allowed to fit the 512k limit on prediction modes coding (0: no degradation, 100: maximum possible degradation) width (int), height (int) - Input size (width x height) for YUV crop_x (int), crop_y (int), crop_w (int), crop_h (int) - crop picture with the given rectangle resize_w (int), resize_h (int) - resize picture (after any cropping) Decode WebP image Decode webp image (default format is png): filename = File.expand_path(File.join(File.dirname(__FILE__), "spec/factories/4.webp")) out_filename = File.expand_path(File.join(File.dirname(__FILE__), "tmp/4.png")) WebP.decode(filename, out_filename) Decode webp image to pam, ppm, pgm, bmp, tiff or yuv format of image: filename = File.expand_path(File.join(File.dirname(__FILE__), "spec/factories/4.webp")) out_filename = File.expand_path(File.join(File.dirname(__FILE__), "tmp/4.png")) WebP.decode(filename, out_filename, output_format: :pam) WebP.decode(filename, out_filename, output_format: :ppm) WebP.decode(filename, out_filename, output_format: :pgm) WebP.decode(filename, out_filename, output_format: :bmp) WebP.decode(filename, out_filename, output_format: :tiff) WebP.decode(filename, out_filename, output_format: :yuv) Decode webp image with options: WebP.encode(filename, out_filename, resize_w: 100, resize_h: 200) WebP.encode(filename, out_filename, crop_x: 0, cropt_y: 0, crop_w: 100, crop_h: 100) Possible decode options: bypass_filtering (bool) - disable in-loop filtering no_fancy_upsampling (bool) - don’t use the fancy YUV420 upscaler use_threads (bool) - use multi-threading crop_x (int), crop_y (int), crop_w (int), crop_h (int) - crop picture with the given rectangle resize_w (int), resize_h (int) - resize picture (after any cropping) Rails assets pipeline integration For integration with Rails 3+ you can use very simple rake task: # Place this code in lib/tasks/assets.rake require 'webp-ffi' namespace :assets do desc "Create .gz versions of assets" task :webp => :environment do image_types = /\.(?:png|jpe?g)$/ public_assets = File . join ( Rails . root , "public" , Rails . application . config . assets . prefix ) Dir [ " #{ public_assets } /**/*" ]. each do | filename | next unless filename =~ image_types mtime = File . mtime ( filename ) webp_file = " #{ filename } .webp" next if File . exist? ( webp_file ) && File . mtime ( webp_file ) >= mtime begin WebP . encode ( filename , webp_file ) File . utime ( mtime , mtime , webp_file ) puts "Webp converted image #{ webp_file } " rescue => e puts "Webp convertion error of image #{ webp_file } . Error info: #{ e . message } " end end end # Hook into existing assets:precompile task Rake :: Task [ "assets:precompile" ]. enhance do Rake :: Task [ "assets:webp" ]. invoke end end Contributing Fork it Create your feature branch ( git checkout -b my-new-feature ) Commit your changes ( git commit -am 'Add some feature' ) Push to the branch ( git push origin my-new-feature ) Create new Pull Request This project is maintained by le0pard Hosted on GitHub Pages — Theme by orderedlist