fixtures/cart_edges.png @@ -1,14 +1,14 @@ class EdgeDetector - VERBOSE=false + VERBOSE=true # Use Prewitt Edge Detection Y_MASK = [[-1, 0, 1], [-1, 0, 1], [-1, 0, 1]] - X_MASK = [[ 1, 1, 1], - [ 0, 0, 0], - [-1, -1, -1]] + X_MASK = [[ -1, -1, -1], + [ 0, 0, 0], + [ 1, 1, 1]] MAX_MAGNITUDE = begin QuantumRange @@ -71,7 +71,7 @@ class EdgeDetector if column == 0 || row == 0 || column == @img.right || row == @img.bottom magnitude = MAX_MAGNITUDE else - # for the 8 surrounding pixels to x,y, apply the filter value and add to the xsum + # for the 8 surrounding pixels to x,y, apply the filter [-1,0,1].each do |x_offset| [-1,0,1].each do |y_offset| @@ -85,7 +85,7 @@ class EdgeDetector end end - magnitude = xsum.abs + ysum.abs + magnitude = Math.sqrt(xsum * xsum + ysum * ysum) end magnitude = [magnitude, MAX_MAGNITUDE].min # cap at MAX_MAGNITUDE lib/seamcarver/edge_detector.rb @@ -14,7 +14,7 @@ describe EdgeDetector do ed = EdgeDetector.new(@fixtures_path + "/cart_gray.jpg") edges = ed.detect_edges - edges.should nearly_equal_image(@fixtures_path + "/cart_edges.jpg") + edges.should nearly_equal_image(@fixtures_path + "/cart_edges.png") end it "should only accept grayscale images for edge detection" do spec/edge_detector_spec.rb fixtures/cart_edges.jpg 8b51e700bafed256dadf6ea45dbe8e79c1ad99d8 Cory cory.forsyth@gmail.com http://github.com/bantic/image_labs/commit/bf5ce26a31be2cbf8bd6512fb3737139378e05e9 bf5ce26a31be2cbf8bd6512fb3737139378e05e9 2009-03-22T14:43:58-07:00 2009-03-22T14:43:58-07:00 Fixed Prewitt x-mask kernel and changed edge detection to use Math.sqrt 89cf9078efcfc577ee70432863e39175055db9ef Cory cory.forsyth@gmail.com