Merge pull request #16 from fetlife/switch-to-magnus

Replace `rutie` with `magnus`

Author: Antti

.github/workflows/workflow.yml

@@ -9,10 +9,12 @@ jobs:
       - uses: ruby/setup-ruby-pkgs@v1
         with:
           ruby-version: 3.3.0
-      - run: sudo apt-get update && sudo apt-get install -y libopencv-dev
+      - run: sudo apt-get update && sudo apt-get install -y libopencv-dev libvips
       - run: gem update --system
-      - run: gem build libfacedetection.gemspec
-      - run: gem install $(ls -1 *.gem)
+      - run: rake gem
+      - run: gem install $(ls -1 pkg/*.gem)
+      - run: bundle install
+      - run: ruby tests/test_detection.rb
   # compile_native_gem:
   #   name: Compile native gem
   #   runs-on: ubuntu-latest

.gitignore

@@ -5,3 +5,4 @@
 /target
 Gemfile.lock
 .ruby-version
+*.gem

Cargo.lock

@@ -8,10 +8,9 @@ authors = ["Fetlife <[email protected]>"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-anyhow = "1.0.62"
 libfacedetection = { git = "https://github.com/fetlife/libfacedetection-rs.git", optional = true, rev="7426f33ba101514932a5ef58456761735c7bf3dc" }
-opencv = { version = "0.66", optional = true }
-rutie = { version="0.8.4", features = ["no-link"] }
+opencv = { version = "0.88.6", optional = true, features=["clang-runtime"] }
+magnus = { version="0.6.2" }
 
 [lib]
 name = "libfacedetection_ruby"

Cargo.toml

@@ -0,0 +1,47 @@
+module Libfacedetection
+  module FaceDetection
+    require 'ruby-vips'
+    require 'ffi'
+
+    LIB_FACEDETECTION_MAX_SIZE = 400.0
+
+    extend self
+
+    # vips_img: Vips::Image
+    def detect_faces(vips_img)
+      scale =
+      if vips_img.width > vips_img.height
+        LIB_FACEDETECTION_MAX_SIZE / vips_img.width
+      else
+        LIB_FACEDETECTION_MAX_SIZE / vips_img.height
+      end
+      # convert RGB -> BGR
+      rgb_bands = vips_img.bandsplit
+      bgr = Vips::Image.bandjoin([rgb_bands[2], rgb_bands[1], rgb_bands[0]])
+      # resize to a smaller size - libfacedetection works with smaller images
+      # or perhaps a larger one, but results are not guaranteed to be better
+      resized = bgr.resize(scale)
+
+      mem = resized.write_to_memory
+      ptr = FFI::MemoryPointer.from_string(mem)
+      faces = Libfacedetection.detect_libfacedetection_image_data(ptr.address, resized.width, resized.height)
+      faces.map do |face|
+        scale_face(face, scale)
+      end
+    end
+
+    private
+
+    def scale_face(face, scale)
+      face[:x] = (face[:x] / scale).round
+      face[:y] = (face[:y] / scale).round
+      face[:width] = (face[:width] / scale).round
+      face[:height] = (face[:height] / scale).round
+      face[:landmarks] = face[:landmarks].map do |landmark|
+        [(landmark[0] / scale).round, (landmark[1] / scale).round]
+      end
+      face
+    end
+  end
+
+end