Uniform Noise and Image Palette examples

Author: monkstone

basics/image/data/akt.jpg

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+#!/usr/bin/env jruby
+# After an idea by Kevin Workman and processing.py example by Jorg Kantel
+# https://happycoding.io/examples/p5js/images/image-palette
+# http://blog.schockwellenreiter.de/2021/08/2021080401.html
+
+require 'picrate'
+
+class ImagePalette < Processing::App
+  WIDTH = 800
+  HALF = 400
+  HEIGHT = 640
+  attr_reader :img, :img2, :palette, :pixel_array
+  MIN = 999_999
+  WEB = %w[#264653 #2a9d8f #e9c46a #f4a261 #e76f51].freeze
+
+  def settings
+    size(WIDTH, HEIGHT)
+  end
+
+  def setup
+    sketch_title('Image Palette')
+    @img = load_image(data_path('akt.jpg'))
+    @img2 = create_image(HALF, height, RGB)
+    @palette = web_to_color_array(WEB)
+    img.load_pixels
+    img2.load_pixels
+    no_loop
+  end
+
+  def draw
+    grid(HALF, height) do |x, y|
+      img_color = img.pixels[x + y * HALF]
+      img2.pixels[x + y * HALF] = get_palette_color(img_color)
+    end
+    image(img, 0, 0)
+    image(img2, HALF, 0)
+  end
+
+  def get_palette_color(img_color)
+    min_distance = MIN
+    img_r = img_color >> 16 & 0xFF
+    img_g = img_color >> 8 & 0xFF
+    img_b = img_color & 0xFF
+    target_color = 0
+    palette.each do |c|
+      palette_r = c >> 16 & 0xFF
+      palette_g = c >> 8 & 0xFF
+      palette_b = c & 0xFF
+      color_distance = dist(img_r, img_g, img_b,
+                            palette_r, palette_g, palette_b)
+      if color_distance < min_distance
+        target_color = c
+        min_distance = color_distance
+      end
+    end
+    target_color
+  end
+end
+
+ImagePalette.new

basics/image/image_palette.rb

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+### UniformNoise by micycle ###
+
+See [source code](https://github.com/micycle1/UniformNoise)
+You will need maven to build (no other dependencies)

external_library/java/uniform_noise/README.md

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+#!/usr/bin/env jruby
+require 'picrate'
+
+class UniformNoiseTest < Processing::App
+  load_library :uniform_noise
+
+  java_import 'micycle.uniformnoise.UniformNoise'
+  java_import 'java.awt.Color'
+
+  OCTAVES = 4
+
+  def setup
+    sketch_title 'Uniform Noise Test'
+    load_pixels
+    @unoise = UniformNoise.new
+  end
+
+  def draw
+    grid(width, height) do |x, y|
+      val = if x < width / 2
+              (SmoothNoise.noise(x * 0.015, y * 0.015, frame_count * 0.035) + 1) / 2
+            else
+              @unoise.uniform_noise(x * 0.0085, y * 0.0085, frame_count * 0.01, OCTAVES, 0.5)
+            end
+      pixels[y * width + x] = Color.HSBtoRGB(val, 1, 1)
+    end
+    update_pixels
+  end
+
+  def settings
+    size(800, 800, P2D)
+  end
+end
+
+UniformNoiseTest.new